Biomaterial Database

Influence of potassium, sodium, perfusion pressure, and isoprenaline on renin release induced by acute calcium deprivation. 1979

J C Fray, and C S Park

1. These studies were conducted in isolated perfused rat kidneys to determine the influence of perfusion pressure, isoprenaline, K, and Na on renin release stimulated by acute Ca deprivation.2. Removing Ca from the perfusion medium for 10 min stimulated renin release and reintroducing Ca returned it toward control values.3. Lowering concentration of Ca in the perfusion medium from 5 to 0 mM increased the effectiveness of low perfusion pressure (50 mmHg) and isoprenaline (2.43 muM) in stimulating renin release.4. At higher perfusion pressure (150 mmHg), renin release was inhibited in perfusion medium containing 2.5 mM-Ca but not in medium containing no Ca. In fact, high perfusion pressure stimulated renin release when the perfusion medium was without Ca.5. Raising concentration of K in the perfusion medium partially inhibited the renin release induced by Ca deprivation. Adding 5 mM-EGTA to Ca-deprived medium stimulated a greater rate of renin release than that of Ca-deprived medium alone. This greater renin release was also partially inhibited by raising K concentration in the perfusion medium.6. Lowering concentration of Na in the perfusion medium from 145 to 25 mM partially inhibited the renin release induced by Ca deprivation in the presence of low perfusion pressure or isoprenaline.7. These findings support the hypothesis that a decreased concentration of Ca in the cytoplasm of the juxtaglomerular cell stimulates renin release and increased Ca inhibits renin release. The sequence of events which leads to changes in cytoplasmic Ca might depend on the concentration of Ca in the perfusion medium, the renal perfusion pressure, the membrane potential of the juxtaglomerular cells, and Ca-Na exchange mechanisms.

UI	MeSH Term	Description	Entries
D007545	Isoproterenol	Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.	Isoprenaline,Isopropylarterenol,4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol,Euspiran,Isadrin,Isadrine,Isopropyl Noradrenaline,Isopropylnoradrenaline,Isopropylnorepinephrine,Isoproterenol Hydrochloride,Isoproterenol Sulfate,Isuprel,Izadrin,Norisodrine,Novodrin,Hydrochloride, Isoproterenol,Noradrenaline, Isopropyl,Sulfate, Isoproterenol
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D008297	Male		Males
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011312	Pressure	A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Pressures
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
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
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
D012636	Secretory Rate	The amount of a substance secreted by cells or by a specific organ or organism over a given period of time; usually applies to those substances which are formed by glandular tissues and are released by them into biological fluids, e.g., secretory rate of corticosteroids by the adrenal cortex, secretory rate of gastric acid by the gastric mucosa.	Rate, Secretory,Rates, Secretory,Secretory Rates