Pressor Activity in Extracts of the Corpuscles of Stannius From the European Eel ( Anguilla Anguilla L.)

SUMMARY Extracts of corpuscles of Stannius from the silver eel have been shown to contain a substance with a powerful pressor action on intravenous injection into the rat. This material resembles mammalian renin in being non-diffusible through cellophane, heat-labile, and destroyed by acidification to pH 2. The effect in the rat differs, however, from that produced by mammalian renin in being more prolonged, and frequently biphasic. Pressor activity has also been demonstrated in extracts of kidneys from freshwater silver eels. Incubation of kidney extract with mammalian renin-substrate produced an angiotensin-like pressor substance. Both renal and corpuscular extracts had a prolonged pressor effect on intravenous injection into the eel. The identities of these pressor materials have not been finally established. Removal of the corpuscles of Stannius from freshwater silver eels was followed by a drop in blood pressure to levels normally found in eels adapted to seawater. The possible existence, in the eel, of a renin-angiotensin system analogous to that existing in mammals is discussed.