IBIMOL   23987
INSTITUTO DE BIOQUIMICA Y MEDICINA MOLECULAR PROFESOR ALBERTO BOVERIS
Unidad Ejecutora - UE
artículos
Título:
Mitochondrial dysfunction as a mediator of hippocampal apoptosis in a model of hepatic encephalopathy.
Autor/es:
BUSTAMANTE, J.; LORES-ARNAIZ, S.; TALLIS, S.; ROSELLÓ, D.; LAGO, N.; LEMBERG, A.; BOVERIS, A. ; PERAZZO, JC.
Revista:
MOLECULAR AND CELLULAR BIOCHEMISTRY
Editorial:
SPRINGER
Referencias:
Año: 2011
ISSN:
0300-8177
Resumen:
Abstract. In this study here we describe the presence of apoptosis, associated with a
mitochondrial dysfunction in the hippocampus of animals in a model of minimal hepatic
encephalopathy (MHE). This experimental model was studied after 10 days of induced
portal vein calibrated stricture, leading to portal hypertension and to a moderate
hyperammonemia, without the presence of other evident central nervous system
changes. The molecular mechanisms here proposed, indicate the presence of apoptosis
intrinsic pathways, that point to hippocampal mitochondria as an important mediator of
the hypertension and slight hyperammonemia observed. In this model of MHE, the
presence of DNA fragmentation in positive GFAP cells is documented by 2.3-times
increased number of TUNEL-positive cells. These findings together with 5 times higher
expression of the proapoptotic member of the Bcl-2 family, Bax, associated to the outer
mitochondrial membrane, indicate the presence of apoptosis in this experimental model.
A detailed analysis of the hippocampal mitochondrial physiology was performed after
mitochondrial isolation. The determination of the respiratory rate in the presence of
malate plus glutamate and ADP showed 45% decrease in respiratory control in MHE
animals as compared with the Sham group. A marked decrease of cytochrome oxidase
(complex IV of the electron transport chain) was also observed, showing 46% less
activity in hippocampal mitochondria from MHE animals. In addition, mitochondria
from these animals showed less ability to maintain membrane potential (´ém) which
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
mitochondrial dysfunction in the hippocampus of animals in a model of minimal hepatic
encephalopathy (MHE). This experimental model was studied after 10 days of induced
portal vein calibrated stricture, leading to portal hypertension and to a moderate
hyperammonemia, without the presence of other evident central nervous system
changes. The molecular mechanisms here proposed, indicate the presence of apoptosis
intrinsic pathways, that point to hippocampal mitochondria as an important mediator of
the hypertension and slight hyperammonemia observed. In this model of MHE, the
presence of DNA fragmentation in positive GFAP cells is documented by 2.3-times
increased number of TUNEL-positive cells. These findings together with 5 times higher
expression of the proapoptotic member of the Bcl-2 family, Bax, associated to the outer
mitochondrial membrane, indicate the presence of apoptosis in this experimental model.
A detailed analysis of the hippocampal mitochondrial physiology was performed after
mitochondrial isolation. The determination of the respiratory rate in the presence of
malate plus glutamate and ADP showed 45% decrease in respiratory control in MHE
animals as compared with the Sham group. A marked decrease of cytochrome oxidase
(complex IV of the electron transport chain) was also observed, showing 46% less
activity in hippocampal mitochondria from MHE animals. In addition, mitochondria
from these animals showed less ability to maintain membrane potential (´ém) which
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
mitochondrial dysfunction in the hippocampus of animals in a model of minimal hepatic
encephalopathy (MHE). This experimental model was studied after 10 days of induced
portal vein calibrated stricture, leading to portal hypertension and to a moderate
hyperammonemia, without the presence of other evident central nervous system
changes. The molecular mechanisms here proposed, indicate the presence of apoptosis
intrinsic pathways, that point to hippocampal mitochondria as an important mediator of
the hypertension and slight hyperammonemia observed. In this model of MHE, the
presence of DNA fragmentation in positive GFAP cells is documented by 2.3-times
increased number of TUNEL-positive cells. These findings together with 5 times higher
expression of the proapoptotic member of the Bcl-2 family, Bax, associated to the outer
mitochondrial membrane, indicate the presence of apoptosis in this experimental model.
A detailed analysis of the hippocampal mitochondrial physiology was performed after
mitochondrial isolation. The determination of the respiratory rate in the presence of
malate plus glutamate and ADP showed 45% decrease in respiratory control in MHE
animals as compared with the Sham group. A marked decrease of cytochrome oxidase
(complex IV of the electron transport chain) was also observed, showing 46% less
activity in hippocampal mitochondria from MHE animals. In addition, mitochondria
from these animals showed less ability to maintain membrane potential (´ém) which
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
mitochondrial dysfunction in the hippocampus of animals in a model of minimal hepatic
encephalopathy (MHE). This experimental model was studied after 10 days of induced
portal vein calibrated stricture, leading to portal hypertension and to a moderate
hyperammonemia, without the presence of other evident central nervous system
changes. The molecular mechanisms here proposed, indicate the presence of apoptosis
intrinsic pathways, that point to hippocampal mitochondria as an important mediator of
the hypertension and slight hyperammonemia observed. In this model of MHE, the
presence of DNA fragmentation in positive GFAP cells is documented by 2.3-times
increased number of TUNEL-positive cells. These findings together with 5 times higher
expression of the proapoptotic member of the Bcl-2 family, Bax, associated to the outer
mitochondrial membrane, indicate the presence of apoptosis in this experimental model.
A detailed analysis of the hippocampal mitochondrial physiology was performed after
mitochondrial isolation. The determination of the respiratory rate in the presence of
malate plus glutamate and ADP showed 45% decrease in respiratory control in MHE
animals as compared with the Sham group. A marked decrease of cytochrome oxidase
(complex IV of the electron transport chain) was also observed, showing 46% less
activity in hippocampal mitochondria from MHE animals. In addition, mitochondria
from these animals showed less ability to maintain membrane potential (´ém) which
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
mitochondrial dysfunction in the hippocampus of animals in a model of minimal hepatic
encephalopathy (MHE). This experimental model was studied after 10 days of induced
portal vein calibrated stricture, leading to portal hypertension and to a moderate
hyperammonemia, without the presence of other evident central nervous system
changes. The molecular mechanisms here proposed, indicate the presence of apoptosis
intrinsic pathways, that point to hippocampal mitochondria as an important mediator of
the hypertension and slight hyperammonemia observed. In this model of MHE, the
presence of DNA fragmentation in positive GFAP cells is documented by 2.3-times
increased number of TUNEL-positive cells. These findings together with 5 times higher
expression of the proapoptotic member of the Bcl-2 family, Bax, associated to the outer
mitochondrial membrane, indicate the presence of apoptosis in this experimental model.
A detailed analysis of the hippocampal mitochondrial physiology was performed after
mitochondrial isolation. The determination of the respiratory rate in the presence of
malate plus glutamate and ADP showed 45% decrease in respiratory control in MHE
animals as compared with the Sham group. A marked decrease of cytochrome oxidase
(complex IV of the electron transport chain) was also observed, showing 46% less
activity in hippocampal mitochondria from MHE animals. In addition, mitochondria
from these animals showed less ability to maintain membrane potential (´ém) which
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
mitochondrial dysfunction in the hippocampus of animals in a model of minimal hepatic
encephalopathy (MHE). This experimental model was studied after 10 days of induced
portal vein calibrated stricture, leading to portal hypertension and to a moderate
hyperammonemia, without the presence of other evident central nervous system
changes. The molecular mechanisms here proposed, indicate the presence of apoptosis
intrinsic pathways, that point to hippocampal mitochondria as an important mediator of
the hypertension and slight hyperammonemia observed. In this model of MHE, the
presence of DNA fragmentation in positive GFAP cells is documented by 2.3-times
increased number of TUNEL-positive cells. These findings together with 5 times higher
expression of the proapoptotic member of the Bcl-2 family, Bax, associated to the outer
mitochondrial membrane, indicate the presence of apoptosis in this experimental model.
A detailed analysis of the hippocampal mitochondrial physiology was performed after
mitochondrial isolation. The determination of the respiratory rate in the presence of
malate plus glutamate and ADP showed 45% decrease in respiratory control in MHE
animals as compared with the Sham group. A marked decrease of cytochrome oxidase
(complex IV of the electron transport chain) was also observed, showing 46% less
activity in hippocampal mitochondria from MHE animals. In addition, mitochondria
from these animals showed less ability to maintain membrane potential (´ém) which
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
In this study here we describe the presence of apoptosis, associated with a
mitochondrial dysfunction in the hippocampus of animals in a model of minimal hepatic
encephalopathy (MHE). This experimental model was studied after 10 days of induced
portal vein calibrated stricture, leading to portal hypertension and to a moderate
hyperammonemia, without the presence of other evident central nervous system
changes. The molecular mechanisms here proposed, indicate the presence of apoptosis
intrinsic pathways, that point to hippocampal mitochondria as an important mediator of
the hypertension and slight hyperammonemia observed. In this model of MHE, the
presence of DNA fragmentation in positive GFAP cells is documented by 2.3-times
increased number of TUNEL-positive cells. These findings together with 5 times higher
expression of the proapoptotic member of the Bcl-2 family, Bax, associated to the outer
mitochondrial membrane, indicate the presence of apoptosis in this experimental model.
A detailed analysis of the hippocampal mitochondrial physiology was performed after
mitochondrial isolation. The determination of the respiratory rate in the presence of
malate plus glutamate and ADP showed 45% decrease in respiratory control in MHE
animals as compared with the Sham group. A marked decrease of cytochrome oxidase
(complex IV of the electron transport chain) was also observed, showing 46% less
activity in hippocampal mitochondria from MHE animals. In addition, mitochondria
from these animals showed less ability to maintain membrane potential (´ém) which
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
´ém) which
was 13% lower than the Sham group. Light scattering experiments showed that
mitochondria from MHE animals were more sensitive to swell in the presence of
increased calcium concentrations as compared with the Sham group. In addition, in
vitro studies performed in mitochondria from Sham animals showed that mitochondrial
permeability transition (MPT) could be a mitochondrial mediator of the apopototic
signaling in the presence of NH4
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
+ and calcium.
4
+ and calcium.and calcium.