AJP - Regulatory, Integrative and Comparative Physiology, Vol 266, Issue 6 1891-R1895, Copyright © 1994 by American Physiological Society
Olfactory bulbectomy counteracts inhibitory effect of food restriction on reproductive function
D. R. Pieper, C. A. Lobocki and K. H. Karo
Department of Physiology, Providence Hospital, Southfield, Michigan 48037.
Previous studies have shown that bilateral removal of the olfactory bulbs
(BX) results in a large increase in gonadotropin secretion in golden
hamsters. The principal question addressed by the present study was whether
BX would offset the inhibitory effect of food restriction on reproductive
function. BX or sham (SH) BX male golden hamsters were fed ad libitum or
were restricted to only enough food to maintain them at 70% of the body
weight of control groups fed ad libitum. The SH-70% group underwent marked
testicular regression after approximately 6-8 wk, but the testes size of
the BX-70% hamsters decreased only in proportion to the decrease in body
weight. The BX food-restricted group had to be fed more food to maintain
the same weight as the SH-70% hamsters, and the BX-70% group also had a
higher core body temperature, lower percent body fat, and higher serum free
thyroxine levels than SH food-restricted animals. In summary, removal of
the olfactory bulbs appears to facilitate tonic gonadotropin secretion,
such that food restriction is no longer capable of inducing testicular
regression. In addition, the olfactory bulbs may have a strong influence on
metabolic function in golden hamsters.
