Effects of intracerebroventricularly and intraperitoneally administered growth hormone on body weight and food intake in fa/fa Zucker rats.
Growth hormone (GH) possesses multiple metabolic effects, in particular with regard to glucose and lipid homeostasis. Studies on the effects of GH on body weight and food and water intake are scarce and have yielded controversial results. We investigated the effects of different modes of GH administration on the parameters of body weight and food intake as well as on insulin and leptin concentrations in fa/fa Zucker rats. In control experiments, aqua pro injection was given. GH was administered over a time period of 11 days at a daily dose of 250 microg intraperitoneally (i.p.) and 25 microg intracerebroventricularly (i.c.v.). While both food intake and body weight were found to be unaltered in the four groups after this observation period, there was an enhanced food intake and consecutively an increase in body weight over the day period when compared to the night period in the groups of rats that received GH i.c.v. or i.p. This tendency was also shown for water intake. Insulin and leptin concentrations were similar in all groups. Thus, injection of GH appears to modify food intake-related behavior, since the periods of enhanced food and water intake were shifted from night- to daytime. Thus, while in general the metabolic parameters remained unchanged, the activity pattern was clearly modified.
Schulz
Carla
C
Department of Endocrinology and Metabolism, University Clinic of Magdeburg, Germany.
Wieczorek
Ingo
I
Reschke
Kirsten
K
Lehnert
Hendrik
H
D000818:Animals; D001835:Body Weight / Q000187:drug effects*; D002352:Carrier Proteins / Q000235:genetics; D004195:Disease Models, Animal; D004435:Eating / Q000187:drug effects*; D005247:Feeding Behavior; D013006:Growth Hormone / Q000008:administration & dosage*; D006720:Homozygote; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D007328:Insulin / Q000097:blood*; D020738:Leptin / Q000097:blood*; D008297:Male; D024821:Metabolic Syndrome; D009154:Mutation; D051381:Rats; D011924:Rats, Zucker; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D013997:Time Factors
D002352:Carrier Proteins; D007328:Insulin; D020738:Leptin; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D013006:Growth Hormone