IMBICE   05372
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA CELULAR
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Testicular Function in Fructose-Induced Insulin-Resistant Rats.
Autor/es:
LI MARQUES; CM MELLILLO; A RASHIA; B MAIZTEGUI; MO SUESCUN
Lugar:
Washington, DC
Reunión:
Congreso; 91st Annual Meeting ENDO 09; 2009
Institución organizadora:
The Endocrine Society
Resumen:
P3-284] Testicular Function in Fructose-Induced Insulin-Resistant Rats.
LI Marques, CM Mellillo, A Rashia, B Maiztegui, MO Suescun,
Reproductive Endocrinology, IMBICE, CIC-CCT La Plata-CONICET, La
Plata, Argentina; Chair of Endocrinology, Fac de Ciencias Exactas, UNLP,
La Plata, Argentina; CENEXA, UNLP-CCT La Plata-CONICET, La Plata,
Argentina
Lately, there has been increasing evidence of the interaction between the
metabolic syndrome (MS) and testicular function. Although the exact
pathophysiological mechanisms remain unclear, some peripheral signals such
as adipocyte- and stomach-derived Leptin and Ghrelin respectively, appear to
play crucial roles in such interaction. A key factor contributing to the MS is
insulin resistance (IR) and the subsequent insulin increase. The aim of the
present study was to analyze IR effect on testicular steroidogenesis and the
action of Leptin and Ghrelin as possible links between IR and testicular
dysfunction. Fructose-rich diet (FRD) is a good experimental model of MS and
IR. Normal male rats were fed with a standard commercial diet and water
without (control, C ) or with 10% fructose (FRD) for three weeks. Blood glucose
(strips), triglyceride (commercial kit) and insulin (radioimmunoassay) levels
were measured at sacrifice. In vitro testosterone production by purified Leydig
cells (LC) isolated from C and FRD rats was evaluated. The direct effect of
Ghrelin (1nM) and Leptin (1nM) on testosterone production by LC incubated
during 3 h under basal and hCG-stimulated conditions in FRD and C groups
was also compared. Finally, mRNA Ghrelin receptor (GHS-r) expression
(relative to -actin expression) by RT-PCR real time was evaluated in aliquots of
testicular tissue and LC from FRD and C rats. FRD rats presented
normoglycemia but impaired glucose tolerance, hypertriglyceridemia,
hyperinsulinemia, and increased HOMA-IR index. Results showed that hCG
(0.1-10 ng/mL) stimulated testosterone production was lower (30%) in purified
LC from FRD than in C rats, p<0.05. We observed a similar inhibitory effect of
Leptin on hCG-stimulated testosterone production by FRD and C purified LC
(Leptin 1nM, hCG 1ng/mL, FRD: 49% vs C: 50%, NS). However Ghrelin
inhibited differentially hCG-stimulated testosterone production in both groups
(Ghrelin 1nM, hCG 1 ng/mL, FRD: 35% vs C: 23 %, p<0.05). Moreover, mRNA
GHSr-1a expression showed a five fold increase in testicular tissue and LC from
FRD respect to C rats, p<0.05. Our data show that in vitro steroidogenic activity
by LC, direct Ghrelin effect on hCG-stimulated testosterone production by
purified LC and mRNA GHSr-1a expression in testicular tissue are altered
under insulin resistance conditions, which suggests a pivotal local role of
Ghrelin in testicular dysfunction.
Supported by A grant from Consejo Nacional de Investigaciones Cientificas y
Tecnicas (CONICET), PIP 5331.
by LC, direct Ghrelin effect on hCG-stimulated testosterone production by
purified LC and mRNA GHSr-1a expression in testicular tissue are altered
under insulin resistance conditions, which suggests a pivotal local role of
Ghrelin in testicular dysfunction.
Supported by A grant from Consejo Nacional de Investigaciones Cientificas y
Tecnicas (CONICET), PIP 5331.
by LC, direct Ghrelin effect on hCG-stimulated testosterone production by
purified LC and mRNA GHSr-1a expression in testicular tissue are altered
under insulin resistance conditions, which suggests a pivotal local role of
Ghrelin in testicular dysfunction.
Supported by A grant from Consejo Nacional de Investigaciones Cientificas y
Tecnicas (CONICET), PIP 5331.
by LC, direct Ghrelin effect on hCG-stimulated testosterone production by
purified LC and mRNA GHSr-1a expression in testicular tissue are altered
under insulin resistance conditions, which suggests a pivotal local role of
Ghrelin in testicular dysfunction.
Supported by A grant from Consejo Nacional de Investigaciones Cientificas y
Tecnicas (CONICET), PIP 5331.
by LC, direct Ghrelin effect on hCG-stimulated testosterone production by
purified LC and mRNA GHSr-1a expression in testicular tissue are altered
under insulin resistance conditions, which suggests a pivotal local role of
Ghrelin in testicular dysfunction.
Supported by A grant from Consejo Nacional de Investigaciones Cientificas y
Tecnicas (CONICET), PIP 5331.
by LC, direct Ghrelin effect on hCG-stimulated testosterone production by
purified LC and mRNA GHSr-1a expression in testicular tissue are altered
under insulin resistance conditions, which suggests a pivotal local role of
Ghrelin in testicular dysfunction.
Supported by A grant from Consejo Nacional de Investigaciones Cientificas y
Tecnicas (CONICET), PIP 5331.
in vitro steroidogenic activity
by LC, direct Ghrelin effect on hCG-stimulated testosterone production by
purified LC and mRNA GHSr-1a expression in testicular tissue are altered
under insulin resistance conditions, which suggests a pivotal local role of
Ghrelin in testicular dysfunction.
Supported by A grant from Consejo Nacional de Investigaciones Cientificas y
Tecnicas (CONICET), PIP 5331.
Date: Friday, June 12, 2009Friday, June 12, 2009
Session Info: POSTER SESSION: BASIC/TRANSLATIONAL - Testicular
Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM)
Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM)
Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM)
Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM)
Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM)
Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM)
POSTER SESSION: BASIC/TRANSLATIONAL - Testicular
Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM)
Presentation Time: 1:30 PM1:30 PM
Room: Halls A & BHalls A & B