Pharmacological doses of calcitonin reduce sex hormone levels in rat plasma.

Administration of a pharmacological dose of salmon calcitonin into rats (10 MRC U/kg body weight) significantly reduced plasma concentrations of testosterone and estradiol in a time-dependent fashion. This apparently was mediated by a diminished secretion of luteinizing hormone and follicle-stimulating hormone, the levels of which were also significantly reduced after 1 h of calcitonin administration.