Effect of fish angiotensins and angiotensin-like substances on killifish calcium regulation

• Published in: General and comparative endocrinology Vol. 43; no. 3; pp. 292 - 298
• Main Authors: Pang, Peter K.T., Pang, Rosemary K., Liu, Vernon K.Y., Sokabe, Hirofumi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.1981
• Subjects: Angiotensin II - pharmacology; Animals; Biological Assay; Calcium - blood; Dose-Response Relationship, Drug; Endocrine Glands - physiology; Fishes - blood; Fishes - physiology; Humans; Kidney - analysis; Killifishes - blood; Male
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1016/0016-6480(81)90287-2

Preparations of fish Stannius corpuscles (C.S.) were studied in the killifish hypocalcemic bioassay. Homogenates of C.S. from killifish, catfish, cod, carp, salmon, and goosefish produced hypocalcemia in the assay fish. Acetic acid (0.25 M) extraction, dialysis, ether extraction, and lyophilization did not affect the hypocalcemic activity. Boiling destroyed the activity. Angiotensin-like substances generated by incubating carp or goosefish C.S. with homologous plasma produced dose-related hypocalcemia in the assay animals. However, synthetic (Asp 1, Ile 5)A II (human angiotensin II) and fish angiotensins generated by incubating carp or eel kidney with homologous plasma produced significant hypercalcemia in the killifish bioassay. We concluded that fish C.S. contain a protein which, when incubated with plasma, generates a hypocalcemic substance with an angiotensin-like pressor property. This hypocalcemic pressor substance is different from true angiotensin which is pressor and hypercalcemic in killifish.