AJP - Regulatory, Integrative and Comparative Physiology, Vol 264, Issue 3 573-R577, Copyright © 1993 by American Physiological Society
Glucoprivation induces anestrus and lipoprivation may induce hibernation in Syrian hamsters
J. E. Schneider, D. G. Friedenson, A. J. Hall and G. N. Wade
Department of Psychology, University of Massachusetts, Amherst 01003.
Previous results supported the notion that estrous cycles in Syrian
hamsters are responsive to the general availability of metabolic fuels,
rather than to either fatty acid or glucose availability per se. To test
this idea, we monitored estrous cycles in hamsters that were fed ad libitum
and treated with a range of doses of 2-deoxy-D-glucose (2-DG), an inhibitor
of glucose utilization. Hamsters treated with 2-DG at doses ranging from
750-1,250 mg/kg showed normal estrous cycles, but higher doses (1,750 or
2,000 mg/kg) induced anestrus. While it is clear from these data that
estrous cycles are affected by glucoprivation, it is not clear whether they
are responsive to decreased fatty acid availability. Groups of hamsters
were fed ad libitum and treated with a range of doses of methyl palmoxirate
(MP), an inhibitor of fatty acid utilization. Some of the hamsters that
received the highest doses became torpid and thus were not tested for
lordosis. None of the euthermic, MP-treated hamsters became anestrous.
Other experiments examined the role of glucose availability in fasted
hamsters. Hamsters with a high body fat content were protected from
fasting-induced anestrus. In contrast, fat food-deprived hamsters treated
with low doses of 2-DG (750 mg/kg) became anestrous. Thus fatty acids
mobilized from adipose tissue did not prevent fasting-induced anestrus when
glucose utilization was blocked. One interpretation is that during fasting
fatty acid utilization spares glucose for other tissues involved in the
control of estrous cycles.(ABSTRACT TRUNCATED AT 250 WORDS)
