Microinfusion of bombesin into the hypothalamic paraventricular nucleus produces hypothermia in the insulin-pretreated rat.
Bombesin-like peptides are widely distributed in the mammalian central nervous system and participate in the regulation of a variety of autonomic functions. Central injection of bombesin produces hypothermia at normal ambient temperatures, but only if the rat has been food-deprived or made hypoglycemic with insulin. Two experiments were conducted to reevaluate the impact of bombesin microinfusion into the hypothalamic paraventricular nucleus (PVN) on core body temperature and feeding behavior. In Experiment 1, bombesin (0.05 and 0.1 microgram/1.0 microliter) produced hypothermia, but not hypophagia, in rats (n = 5) pretreated with insulin (10 U/kg; IM). Since a similar response was observed in rats with injection sites adjacent to the PVN, a smaller injection volume was evaluated in Experiment 2. Hypothermia, but not hypophagia, was observed in rats (n = 5) pretreated with insulin following bombesin (0.025 and 0.05 micrograms/0.5 microliter). Bombesin did not produce hypothermia in rats with injection sites outside of the PVN. These findings suggest that the PVN is a sensitive site for bombesin-induced hypothermia.
Babcock
A M
AM
Department of Psychology, University of South Alabama, Mobile 36688.
Barton
C
C
D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D001839:Bombesin / Q000008:administration & dosage / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects; D005508:Food Deprivation; D007328:Insulin / Q000494:pharmacology*; D008845:Microinjections; D010286:Paraventricular Hypothalamic Nucleus / Q000033:anatomy & histology; D011897:Random Allocation; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D001839:Bombesin