Perinatal expression of adenylyl cyclase subtypes in rat brown
adipose tissue.
Chaudhry, Archana, Laurie A. Muffler, Ruihong Yao, and James G.
Granneman.
Cellular and Clinical Neurobiology Program, Department of
Psychiatry and Behavioral Neurosciences, Wayne State University
School of Medicine, Detroit MI
APStracts 3:0001R, 1996.
The ability of norepinephrine to stimulate adenylyl cyclase (AC)
activity increases during the perinatal period in rat brown adipose
tissue (BAT), and this increase is associated with changes in the
activities of both Gs[alpha] and AC. The purpose of this study was to
determine which AC subtypes are present in neonatal BAT and to
examine whether the perinatal increase in AC activity corresponds to
an increase in the expression of a particular AC subtype. Analysis of
AC messenger RNAs (mRNAs) by nuclease protection assay demonstrated
the presence of mRNAs encoding AC-III, AC-IV, AC-VI and AC-IX in
embryonic and postnatal BAT. Of the subtypes detected, only AC-III
mRNA levels increased substantially during the perinatal period. The
increase in AC-III expression was paralleled by an increase in
isoproterenol (ISO)-stimulated AC activity. Treatment of neonates
with the sympathetic neurotoxin 6-hydroxydopamine (6-HDA) abolished
the perinatal increase in both AC activity and AC-III mRNA levels,
but had no effect on the expression of other AC subtypes. These
results strongly indicate that the increase in AC activity during the
perinatal period is due to an increase in the expression of AC-III.
Received 12 May 1995; accepted in final form 18 October 1995.
APS Manuscript Number R289-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 22 January 96