INVESTIGADORES
SANCHEZ POZZI Enrique Juan
artículos
Título:
Ovine Prolactin Increases Hepatic UDP- Glucuronosyltransferase Activity in Ovariectomized Rats
Autor/es:
LUQUITA, MARCELO G; CATANIA, VIVIANA A; ENRIQUE JUAN SANCHEZ POZZI; MOTTINO, ALDO D
Revista:
JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS
Editorial:
AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS
Referencias:
Año: 1996 vol. 278 p. 921 - 925
ISSN:
0022-3565
Resumen:
The potential role of prolactin in modulating hepatic UDP- glucuronosyltransferase (UGT) activity was studied. Ovariectomized adult female rats were treated with ovine prolactin
(oPRL) at doses of 150, 200, 260, and 310 micrograms/100 g b.wt. per
day, for 4 days. Enzyme assays were performed in native and activated
microsomes with p-nitrophenol as substrate. Activation was achieved
either by including UDP-N-acetylglucosamine
in the incubation mixtures or by preincubating native microsomes with
palmitoyl-lysophosphatidylcholine. Data obtained with UDP-N-acetylglucosamine as activator showed that increasing doses of oPRL produced a progressive increase in enzyme activity
up to a maximum of about 35% over basal values. Immunoblotting of
microsomal protein with anti-UGT antiserum revealed also a
dose-dependent increase in the immunoreactive protein. A kinetic method
for measuring glucuronidating enzyme content confirmed the result of the
immunoblot. oPRL induced minor changes in the physicochemical
properties of the microsomal membrane. Consistent with this observation,
studies performed with palmitoyl-lysophosphatidylcholine as activator
showed no change in UGT latency, suggesting that the functional
characteristics of the enzyme were not substantially affected by oPRL.
The current data support the conclusion that prolactin may act as a modulator of UGT activity by increasing the amount of enzyme.