抄録
Variation of the hypothalamic CRF activity following various stressful stimuli was examined in the normal and adrenalectomized rats by use of the intrapituitary microinjection method. Following stimuli were used such as systemic injections of vasopressin, epinephrine and histamine or exposure to ether vapor plus laparotomy, to formalin gas, to noise or strong light as a strange environment. In spite of the postulated difference among these stimuli, the animals responded rather uniformly with an increment of CRF activity in the median eminence, although the magnitude of the response was variable depending possibly upon the intensity of the stimulus applied. Hypothalamic CRF content of adrenalectomized rats remained unchanged even 20 days, postoperatively, but a marked increment of the activity was demonstrated after a stressful stimulus. Furthermore, there was observed a marked variation in the responsiveness of CRF activity to stress depending on the time of day. Physiological implications of these findings were briefly discussed.
