AJP - Regulatory, Integrative and Comparative Physiology, Vol 272, Issue 3 935-R939, Copyright © 1997 by American Physiological Society
Effects of the fructose analog, 2,5-anhydro-D-mannitol, on food intake and estrous cyclicity in Syrian hamsters
J. E. Schneider
Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
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 analog that is thought to
trigger eating in rats by depleting intracellular levels of ATP. 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 h 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 2,5-AM-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 plus the fatty acid oxidation inhibitor
methyl palmoxirate, or vehicle every 6 h over the first 48 h of the estrous
cycle and were tested for indexes of estrous cyclicity at the end of the
cycle. All hamsters showed normal estrous cycles, regardless of 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 do not increase food intake or inhibit estrous cyclicity in
Syrian hamsters.
