Sexual differentiation of the effects of emotional stress on food intake in rats.
Although gender differences in the response to stress have been reported, differences in stress-induced changes in feeding behavior have not been well studied. In this report, inhibition of food intake was compared in male and female rats following 1 h of restraint, electric footshock, or emotional stress induced by a communication box. Although the three stressors inhibited food intake in both genders, only emotional stress caused a gender difference, a greater inhibition of food intake in female rats (48%) than in male rats (22%). The inhibition of food intake by emotional stress in female rats was more prominent during proestrus than the other phases of estrous cycle. In female rats in proestrus emotional stress showed a greater inhibition of food intake than footshock and restraint. Ovariectomy reduced the inhibition of food intake by emotional stress to the same level as that in male, and replacement with estradiol restored the inhibition to the level of the normal female rats. A corticotropin-releasing factor (CRF) type 1 receptor antagonist prevented emotional stress-induced inhibition of food intake, indicating the involvement of CRF type 1 receptor in emotional stress-induced inhibition of food intake. These results suggest that female rats show a greater inhibition of food intake in response to emotional stress than male rats and that estrogen plays a role in the gender difference.
Department of Physiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8602 Japan.
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Kuriyama
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Shibasaki
D000704:Analysis of Variance; D000818:Animals; D004435:Eating / Q000187:drug effects / Q000502:physiology* / Q000523:psychology; D004597:Electroshock / Q000009:adverse effects; D004644:Emotions / Q000502:physiology*; D015914:Estrogen Replacement Therapy / Q000379:methods; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D008297:Male; D010052:Ovariectomy / Q000379:methods; D011725:Pyridines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018019:Receptors, Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors; D012149:Restraint, Physical / Q000379:methods; D012727:Sex Characteristics; D013315:Stress, Psychological / Q000503:physiopathology*; D000099052:CRF Receptor, Type 1
D011725:Pyridines; D011743:Pyrimidines; D018019:Receptors, Corticotropin-Releasing Hormone; C117406:CRA1000; D000099052:CRF Receptor, Type 1