Abstract:
Hypothalamus plays an important role in energy balance. The hypothalamus ventromedial nucles （VMH） is considered as the brain′s “satiety center”. Neuropeptide Y（NPY） in hypothalamus is a potent orexigenic peptides. To investigate the regulatory role of NPY under different energy demands and food supply, we used mandarin vole (Microtus mandarinus) as the animal model, the expressions of NPY and peptidylglycine α-amidating monooxygenase （PAM） in VMH were observed among lactating females, non-lactating females, and fasting females. The results were as follows: the higher levels of NPY positive neurons were observed in lactating females and fasting females in comparison with non-lactating females;PAM positive neurons of fasting females significantly increased compared with non-lactating females, while there was no remarkable difference between lactating females and non-lactating females. Our results suggest that NPY in VMH also exerts an important role in food consumption and energy balance, which can be activated to increase food intake and reduce energy expenditure in states of lactation and food deprivation; both ascending NPY and PAM neurons were found among fasting females in comparison with non-lactating females，which enable females to meet the requirement of energy and nutriment for themselves. Meanwhile,the expression of PAM largely depends on the physiological situation.
