[Centrally and peripherally induced anorectic actions of salmon calcitonin (sCT) in rats: separation of its novel derivative [Gly8]-sCT].
It has been reported based on animal studies that salmon calcitonin (sCT), besides hypocalcemic action, exhibits a variety of pharmacological actions. The anorectic action has been observed to ensue not only by central administration but also by peripheral injection, indicating that in clinical use to induce hypocalcemia or for other therapeutic purposes, the anorectic action may develop as a side effect. While studying the anorectic effect of [Gly8]-sCT in rats, a derivative of sCT having rather stronger hypocalcemic potency than the mother molecule, it was found that on peripheral injection, the derivative practically lacks the anorectic effect. Thus, a pharmacological evaluation of the novel peptide was made. When injected subcutaneously in rats at a dose level of 1 U/kg, sCT and the derivative induced similar patterns of hypocalcemia in either of which hypocalcemia reached a peak between 1 and 3 hr after injection. No notable difference existed between the action of the two peptides. In rats which were trained to take the daily food need within 2 hr (17:00 approximately 19:00), an intracerebroventricular injection of 1 U/rat of either peptide 30 min before food presentation significantly reduced both food and water intake, causing a loss of body weight as compared with the control which received the injection of saline alone. By subcutaneous injection of 100 U/kg, sCT was also active to decrease food and water intake. The effect was found to last longer than 24 hr and to cause a marked loss in body weight. In contrast, such effects did not develop in rats treated with the derivative. Both peptides were able to suppress the specific binding of 125I-sCT to the membrane fraction of rat brain and kidney.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D001067:Appetite Depressants / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D001921:Brain / Q000378:metabolism; D002116:Calcitonin / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*; D002118:Calcium / Q000097:blood; D007276:Injections, Intraventricular; D007279:Injections, Subcutaneous; D007668:Kidney / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface / Q000378:metabolism
D001067:Appetite Depressants; D001786:Blood Glucose; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface; C028815:salmon calcitonin; C044980:calcitonin, salmon, Gly(8)-; D002116:Calcitonin; D002118:Calcium