Comparative morphology of juxtaglomerular cells. I. Juxtaglomerular cells in fish

Abstract

By the use of the Bowie staining technique, juxtaglomerular cells or their homologues were identified in almost every member of Osteichthyes studied. Despite the fact that juxtaglomerular cells in the mammal, at least, belong to the sodium-retaining rennin–angiotensin–aldosterone system they occurred with frequency in salt-water as well as freshwater fish. Early evidence for the presence of renin in the kidney of certain freshwater fish was strengthened by the identification of granulated afferent arteriolar cells in the kidneys of these species. In an attempt to determine which structural components are necessary for the development of juxtaglomerular cells, their anatomical relationships in the fish were compared with the ones existing in higher forms.