The fructose analogue, 2,5-anhydro-d-mannitol, neither increases
food intake nor inhibits estrous cyclicity in syrian hamsters.
Schneider, Jill E.
Department of Biological Sciences, Lehigh University, Bethlehem,
Pennsylvania 18015
APStracts 3:0385R, 1996.
Hyperphagia and anovulation are both triggered by prior food
deprivation or other treatments that decrease intracellular
availability of metabolic fuels in most species studied. Syrian
hamsters fail to show compensatory hyperphagia, but do show anestrus
in response to these energetic challenges. In the present
experiments, we examined food intake, plasma glucose levels and
estrous cyclicity in Syrian hamsters in response to 2,5-anhydro-D
-mannitol (2,5-AM), a fructose analogue that is thought to trigger
eating in rats by depleting intracellular levels of ATP without
initiating compensatory sympathoadrenal responses. In experiment 1,
female estrous cycling hamsters were treated with 100, 200, 400 or
800 mg/kg 2,5-AM or the vehicle by intraperitoneal injection. Food
intake was measured 1, 2, 4, 8, and 24 hours after treatment. There
were no statistically significant increases in food intake in
response to any dose of 2,5-AM. In experiment 2, blood samples were
drawn at 0, 1, 3, 5, 7 and 25 h after hamsters were treated with 0 or
400 mg/kg 2,5-AM. 2,5-AM treatment resulted in a mild but significant
decrease in plasma glucose levels similar to those seen in 2,5AM
-treated rats, suggesting that 2,5- AM has similar effects on fuel
metabolism in rats and hamsters. In experiment 3, hamsters received
2,5-AM, 2,5-AM + the fatty acid oxidation inhibitor, methyl
palmoxirate (MP) or vehicle every 6 hours over the first 48 h of the
estrous cycle and were tested for indices of estrous cyclicity at the
end of the cycle. All hamsters showed normal estrous cycles,
regardless of the treatment. If 2,5-AM has similar metabolic
consequences in rats and hamsters, the present results suggest that
decreased intracellular levels of ATP and mild hypoglycemia neither
increase food intake nor inhibit estrous cyclicity in Syrian
hamsters. In Syrian hamsters, mechanisms that increase food intake
and inhibit estrous cycles are triggered under the same conditions
that initiate compensatory sympathoadrenal responses.
Received 21 October 1996; accepted in final form 24 May 1996.
APS Manuscript Number R295-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 November 1996