[Comparative effects of an extract of Anguilla Stannius corpuscles and of an active fragment of human parathyroid hormone (1-34 hPTH) on an anuran batracian, Xenopus laevis].

Parathyrin of the corpuscles of Stannius (PCS), glands which are restricted to Holostei and Teleostei, resembles mammalian parathyroid hormone secreted by the parathyroids. These glands made their first phylogenic appearance with Amphibians, whereas the Stannius corpuscles disappeared. We have compared, in the clawed toad, Xenopus laevis, the effects of injections of extracts of corpuscles of Stannius and of the active synthetic fragment of parathyrin (1-34 hPTH). Both hormones elicited hypocalcemia and hypophosphatemia within a 4 days treatment. These results are interpreted according to the hypothesis that in the most primitive Amphibians there are receptors leading to hypocalcemic effect co-existing with the appearance of "new" glands which secrete a hypercalcemic hormone in mammals.