Ingestion, body weight and activity of rats receiving repeated intracerebroventricular infusions of rat satietin.
Satietin is a putative satiety agent that is found in a variety of species including man and the rat. In the first experiment male Sprague-Dawley rats were fitted with chronic third ventricle cannulas and placed in activity wheels. After recovery, animals were intracerebroventricularly (ICV) infused with either sterile rat satietin (r-SAT) (100 micrograms/rat) dissolved in 10 microliters saline (n = 6) or sterile saline (n = 8). Infusions were repeated the next two days. Infusions of r-SAT had no effect on the rats' water intake or activity but did suppress (p less than 0.05) their food consumption when compared to the controls, but only after the first and second infusions. Thus tolerance to r-SAT quickly developed using this schedule of administration. Notably, body weight of the r-SAT infused rats remained attenuated (p less than 0.01) for four days following the first infusion. In the second experiment the rats were ICV infused every fourth day with either r-SAT (100 micrograms/rat) (n = 10) or saline (n = 8) for a total of three infusions. Food, but not water, intake was significantly suppressed after the first and second infusions and lowered nonsignificantly after the third. Body weight was significantly reduced after the first r-SAT infusion and remained statistically reduced for seven days after the third infusion; at a time when the rats' food intake was normal. These data suggest that in addition to a r-SAT suppression of feeding, other r-SAT induced changes (possibly metabolic) may help reduce the rats' body weight. The above dose of r-SAT had no affect on the animals' rectal temperature. The data of the above two experiments reveal that r-SAT infused ICV into rats can suppress the animals' food intake and lead to a prolonged attenuation of body weight.
Bellinger
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Department of Physiology, Baylor College of Dentistry, Dallas, TX 75246.
Mendel
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D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects*; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects*; D006020:Glycopeptides / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains
D006020:Glycopeptides; C035102:satietin