Effect of chronic unpredictable mild stress on brain-pancreas relative protein in rat brain and pancreas.
Brain-pancreas relative protein (BPRP) is a novel protein whose biological function remains unknown. Here, we report a possible role of BPRP in male rats exposed to chronic unpredictable mild stress (CUMS) to induce depression for 3 weeks. Compared to unstressed rats, those exposed to CUMS showed significantly less weight gain with age, decreased consumption of (and preference for) sucrose without a change in total fluid consumption. Exposure to CUMS significantly reduced open-field exploration, rearing and grooming indicative of lethargy, apathy and bodily neglect, respectively. Brain MAO-A and MAO-B activity were both significantly increased in the stressed rats. These results verified induction of depressive symptoms by CUMS. The stressed animals showed a significant reduction in pancreatic BPRP, which was accompanied by an increase in levels of blood sugar and a decrease of insulin. But they showed no apparent alteration in levels or distribution of BPRP in the hippocampal formation, which nevertheless displayed a thinner dentate granule cell layer perhaps related to elevated MAO-B activity. These findings suggest that stress-induced reduction of pancreatic BPRP may cause diabetic symptoms. Whether those symptoms in turn contribute to the onset of depression requires further study.
Lin
Yan-Hua
YH
Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100083, China.
Liu
Ai-Hua
AH
Xu
Ying
Y
Tie
Lu
L
Yu
He-Ming
HM
Li
Xue-Jun
XJ
D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight; D002908:Chronic Disease; D003863:Depression / Q000209:etiology / Q000378:metabolism*; D048909:Diabetes Complications / Q000378:metabolism; D003920:Diabetes Mellitus / Q000378:metabolism; D004195:Disease Models, Animal; D004435:Eating / Q000502:physiology / Q000523:psychology; D005106:Exploratory Behavior / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009928:Organ Specificity; D010179:Pancreas / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013315:Stress, Psychological / Q000150:complications / Q000378:metabolism*
D009419:Nerve Tissue Proteins; D008995:Monoamine Oxidase