[Structural similarities between the hypocalcemia hormone of the corpuscles of Stannius of the eel (Anguilla anguilla L.) and the mammalian parathyroid hormone].

Extracts of the corpuscules of Stannius enhance Eel gill calcium efflux and increase bone resorption in the Rat. Thus the hormone is hypocalcaemic in the Eel although hypercalcaemic in the Rat. We show here that a 15 min. pulse perfusion of a synthetic fragment of human PTH 1-34 had a similar effect on gill calcium fluxes to that of CS extract. Further, we found that Eel plasma contains a substance reacting with five different antibodies against bovine PTH. The concentration of this plasma material is enhanced seven-fold by parenteral calcium and rendered extremely low or absent by CS removal. A convenient name for this major calcium-regulating hormone is parathyrine of the corpuscles of Stannius (PCS) since this reflects both its glandular source and chemical structure.