Effects of goldthioglucose on neuropeptide y messenger rna levels
in the mouse hypothalamus.
Marks, Jonathan L, Kay Waite, David Cameron-Smith, Stephen C Blair,
and Gregory J. Cooney.
Department of Clinical Endocrinology, Westmead Hospital, Westmead,
NSW, 2145 Australia and Department of Endocrinology, Royal Prince
Alfred Hospital, Camperdown, NSW, 2050 Australia
APStracts 2:0347R, 1995.
Elevated hypothalamic neuropeptide Y expression is found in several
rodent genetic models of obesity, but any association in non-genetic
models of obesity is unclear. Consequently, we have measured NPY mRNA
levels in the ventromedial hypothalamus of a well characterized model
of obesity, the goldthioglucose (GTG) injected mouse. Fourteen days
after injection (early stage), animals were hyperphagic but not
obese, hyperglycemic or overtly hyperinsulinemic. Ten weeks after
treatment (late stage), animals were obese, markedly hyperinsulinemic
and hyperglycemic. In both the early and late stages, NPY mRNA levels
were reduced in the arcuate nucleus of GTG-injected animals. Although
overnight fasting doubled NPY mRNA levels in control animals, there
was no change at either stage in GTG-injected animals. NPY mRNA
levels in the deep layers of the cerebral cortex and in the dentate
gyrus were not affected by GTG treatment or overnight fasting. We
conclude that GTG treatment reduces the expression of NPY mRNA in the
arcuate nucleus and that therefore increased hypothalamic NPY
expression is unlikely to be an important factor causing the obesity
and other metabolic changes found in this model.
Received 27 July 1995; accepted in final form 11 December 1995.
APS Manuscript Number R456-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 December 95