evidence is presented to support the hypothesis that a transient curtailment in the inhibitory influence of hypothalamic opioid peptides in the morning of proestrus , sets in motion a chain of temporally-related events starting with augmentation of adrenergic tone , leading to accumulation of neuropeptide y and lhrh in the median eminence and culminating in episodic lhrh and lh hypersecretion in the afternoon of proestrus .
C0020663
hypothalamic
C0023610
lhrh