Renin-angiotensin system in vertebrates: phylogenetic view of structure and function

Abstract

Renin substrate, biological renin activity, and/or renin-secreting cells in kidneys evolved at an early stage of vertebrate phylogeny. Angiotensin (Ang) I and II molecules have been identified biochemically in representative species of all vertebrate classes, although variation occurs in amino acids at positions 1, 5, and 9 of Ang I. Variations have also evolved in amino acid positions 3 and 4 in some cartilaginous fish. Angiotensin receptors, AT and AT homologues, have been identified molecularly or characterized pharmacologically in nonmammalian vertebrates. Also, various forms of angiotensins that bypass the traditional renin-angiotensin system (RAS) cascades or those from large peptide substrates, particularly in tissues, are present. Nonetheless, the phylogenetically important functions of RAS are to maintain blood pressure/blood volume homeostasis and ion-fluid balance via the kidney and central mechanisms. Stimulation of cell growth and vascularization, possibly via paracrine action of angiotensins, and the molecular biology of RAS and its receptors have been intensive research foci. This review provides an overview of: (1) the phylogenetic appearance, structure, and biochemistry of the RAS cascade; (2) the properties of angiotensin receptors from comparative viewpoints; and (3) the functions and regulation of the RAS in nonmammalian vertebrates. Discussions focus on the most fundamental functions of the RAS that have been conserved throughout phylogenetic advancement, as well as on their physiological implications and significance. Examining the biological history of RAS will help us analyze the complex RAS systems of mammals. Furthermore, suitable models for answering specific questions are often found in more primitive animals.

Effects of chronic exposure to 12‰ saltwater on the endocrine physiology of juvenile American alligator (Alligator mississippiensis)

“…Although non-mammalian vertebrate kidneys do not possess JG or have rudimentary JG, there are functional baroreceptor mechanisms in fish [e.g. toadfish (Opsanus tau) (Nishimura et al, 1979), reptiles (turtle, Pseudemys scripta) (Stephens and Creekmore, 1984) and birds (Nishimura, 2017)]. Indeed, in common slider turtles (Pseudemys scripta), barostatic mechanisms were responsible for renin release following hypotension caused by hemorrhage (Stephens and Creekmore, 1984).…”

“…Thus, these findings correspond well with results from the present study in which ALDO levels were not significantly different in SW alligators compared with FW alligators after 5 weeks. ALDO secretion in vertebrates is regulated by ANG II in addition to the adrenocorticotropic hormone (ACTH) and plasma K + (Nishimura, 2017). It has previously been demonstrated that ALDO and CORT secretions in alligators are stimulated by ACTH, which is released from the pituitary gland (Lance and Lauren, 1984;Morici, 1996).…”

“…The renin-angiotensin-aldosterone system (RAAS) is an endocrine system that regulates blood pressure and water-salt balance in all vertebrates (Morici, 1996;Nishimura, 2017;Silldorff and Stephens, 1992a,b). The main enzymes are renin and angiotensin-converting enzyme (ACE), which convert angiotensinogen to angiotensin I (ANG I) and ANG I to angiotensin II (ANG II), respectively.…”

Resveratrol promotes regression of renal carcinoma cells via a renin-angiotensin system suppression-dependent mechanism

“…The renin-angiotensin system (RAS) is classically described as an important endocrine system that regulates blood pressure and electrolyte balance. Studies have demonstrated that RAS may be involved in numerous pathophysiological processes, such as maintaining blood pressure/blood volume homeostasis and ion-fluid balance, phylogenetic advancement, growth promotion and angiogenesis, ontogeny and phylogeny (6). RAS is also involved in several cancers, including glioblastoma multiform (7), and bladder (8) and renal (9) cancers.…”

The Amphibious Mudskipper: A Unique Model Bridging the Gap of Central Actions of Osmoregulatory Hormones Between Terrestrial and Aquatic Vertebrates

“…In mammals, the renin-angiotensin cascade is initiated by the release of renin from the juxtaglomerular cells in the renal afferent arteriole. Renin is released by hypovolemia and subsequent decreases in perfusion pressure at the arteriole ( Kobayashi and Takei, 1996 ; Nishimura, 2017 ). The principal action of the active principle, Ang II, is to restore blood volume by retaining NaCl and water.…”