PHYLOGENETIC ASPECTS OF THE RENIN-ANGIOTENSIN SYSTEM

Abstract

Publisher Summary This chapter discusses the phylogenetic aspects of the renin–angiotensin system (RAS). There are three general facets to the phylogeny of the RAS: the morphological characteristics, the biochemistry, and the physiology. Morphologically, the elements comprise the juxtaglomerular (JG) cells, the macula densa (MD), and the extraglomerular mesangium, lying between the JG cells and the MD. These structures together form the JG apparatus of the mammalian kidney, but this arrangement may be unique to this group. Granular epithelioid cells have not been demonstrated in all types; thus, elasmobranchs and cyclostomes apparently lack these cells and in some bony fish, renal pressor activity occurs in the absence of recognizable JG-type cells. The complete chemical structure of any renin is not known. Various angiotensins have, however, been identified using chemical and pharmacological criteria. Mammalian, avian, reptilian, and teleostean materials reveal that positions 1, 5, and 9 of the decapeptide are variable substitution sites during evolution.