Growth hormone and prolactin levels in stress-induced food intake dysregulation

The hormonal mechanism involved in stress-induced dysregulation of feeding behaviour is not known. In this study anterior pituitary hormones: GH and prolactin/PRL were analyzed, immediately and 60 min. after 1 hr immobilization stress, in rats with enhanced or with diminished food intake. The results show, in rats with diminished food intake after stress, a fall in GH level from 3.9 mU/l to 2.3 mU/l upon exposure and 1.5 mU/l 60 min. after stress. The PRL level elevated to 26.0 mU/l upon exposure to stress in comparison to 9.6 mU/l in the control group, and reached near normal values after 60 min. In rats with enhanced food intake after stress, the GH and PRL levels did not change immediately after stress. Sixty minutes after stress a fall in GH level to 2.4 mU/l was noted, and an elevation of PRL level to 21.9 mU/l. So the change in levels of pituitary hormones in these rats were slower and less pronounced than in rats with suppressed food intake.