Biomaterial Database

Factors controlling the release of renin. A micropuncture study in the cat. 1977

T Morgan, and A Gillies

Blood was collected by micropuncture from the efferent arteriole and superficial venules of the cat's kidney. Blood samples were also collected from the femoral artery and the renal vein. The blood renin concentrations (ng A1 m1-1 2h-1) in a basal state were 37.2 +/- 3.5 (S.E.M.) (n equal to 60) (artery), 32.5 +/- 5.2 [7] (efferent arteriole), 53.5 +/- 4(116) (superficial venule), 54.2+/- 5.4 (43) (renal vein). The corresponding values after haemorrhase were 389 +/- 98 (21), 345 +/- 115 (6), 963 +/- 208 (37), 907 +/- 290 (17), ng A1 m1-1 2h-1. The efferent arteriolar renin did not differ from that in the artery but the concentrations in superficial venular blood and renal vein were higher than arterial concentration. Thus renin entered the circulation between the efferent arteriole and the superficial venule. The blood renin concentration of different superficial venules at a steady arterial renin concentration varied markedly. Into certain venules there appeared to be little or no renin secretion, into others a marked renin secretion, suggesting a heterogeneity of renin secretion by the different nephrons. When the flow of tubular fluid to the macula densa of a group of nephrons was blocked, the renin concentration fell and was significantly less than the renin concentration in venules draining non blocked nephrons and less than in the renal vein. These results suggest that the juxtaglomerular apparatus of the nephrons do not release renin in a synchronous fashion. The release appears to be episodic and is inhibited when flow to the macula densa is ceased. This implies that a high sodium concentration at the macula densa stimulates renin release.

UI	MeSH Term	Description	Entries
D007606	Juxtaglomerular Apparatus	A complex of cells consisting of juxtaglomerular cells, extraglomerular mesangium lacis cells, the macula densa of the distal convoluted tubule, and granular epithelial peripolar cells. Juxtaglomerular cells are modified SMOOTH MUSCLE CELLS found in the walls of afferent glomerular arterioles and sometimes the efferent arterioles. Extraglomerular mesangium lacis cells are located in the angle between the afferent and efferent glomerular arterioles. Granular epithelial peripolar cells are located at the angle of reflection of the parietal to visceral angle of the renal corpuscle.	Apparatus, Juxtaglomerular
D007686	Kidney Tubules, Distal	The portion of renal tubule that begins from the enlarged segment of the ascending limb of the LOOP OF HENLE. It reenters the KIDNEY CORTEX and forms the convoluted segments of the distal tubule.	Distal Kidney Tubule,Distal Renal Tubule,Distal Kidney Tubules,Distal Renal Tubules,Kidney Tubule, Distal,Renal Tubule, Distal,Renal Tubules, Distal,Tubule, Distal Kidney,Tubule, Distal Renal,Tubules, Distal Kidney,Tubules, Distal Renal
D011677	Punctures	Incision of tissues for injection of medication or for other diagnostic or therapeutic procedures. Punctures of the skin, for example may be used for diagnostic drainage; of blood vessels for diagnostic imaging procedures.	Micropunctures,Micropuncture,Puncture
D012083	Renin	A highly specific (Leu-Leu) endopeptidase that generates ANGIOTENSIN I from its precursor ANGIOTENSINOGEN, leading to a cascade of reactions which elevate BLOOD PRESSURE and increase sodium retention by the kidney in the RENIN-ANGIOTENSIN SYSTEM. The enzyme was formerly listed as EC 3.4.99.19.	Angiotensin-Forming Enzyme,Angiotensinogenase,Big Renin,Cryorenin,Inactive Renin,Pre-Prorenin,Preprorenin,Prorenin,Angiotensin Forming Enzyme,Pre Prorenin,Renin, Big,Renin, Inactive
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D005246	Feedback	A mechanism of communication within a system in that the input signal generates an output response which returns to influence the continued activity or productivity of that system.	Feedbacks
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23