Biomaterial Database

The influence of sodium intake on physiological responses to angiotensin II in conscious dogs. 1984

M E Olsen, and E F Meydrech

The renin-angiotensin system (RAS) is suppressed either by high sodium intake or by high levels of angiotensin II (A II). Therefore in prior studies it has been difficult to sort out the influence on the cardiovascular homeostases of different levels of A II and different levels of sodium in the diet respectively. The present study examines the quantitative effects of A II on mean arterial blood pressure (MABP), electrolyte excretion and hormone secretion in conscious dogs on low, normal and high sodium intake with the endogenous RAS blocked with continuous intravenous infusion of enalapril (MK-421). Fourteen dogs on three different Na diets, low, normal and high (5, 30 and 250 mmol/day), were infused continuously with enalapril, 4 mg/kg/day and studied with superinfused A II at rates of 0, 1, 3, 6 and 12 ng/kg/min., each period lasting one week. Converting enzyme inhibitor (CEI) decreased MABP equally in dogs on low and normal sodium intake to about 80% of control, but did not have a significant effect in dogs on high sodium intake. The initial infusion of angiotensin II at the lowest rate had a pronounced effect on MABP in the normal and high sodium states, but had no effect on MABP in the sodium depleted dogs. However, at the higher rates of infusion, the angiotensin II increased the pressure to a similar degree at all levels of sodium intake.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D009318	Natriuresis	Sodium excretion by URINATION.	Natriureses
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.
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
D012084	Renin-Angiotensin System	A BLOOD PRESSURE regulating system of interacting components that include RENIN; ANGIOTENSINOGEN; ANGIOTENSIN CONVERTING ENZYME; ANGIOTENSIN I; ANGIOTENSIN II; and angiotensinase. Renin, an enzyme produced in the kidney, acts on angiotensinogen, an alpha-2 globulin produced by the liver, forming ANGIOTENSIN I. Angiotensin-converting enzyme, contained in the lung, acts on angiotensin I in the plasma converting it to ANGIOTENSIN II, an extremely powerful vasoconstrictor. Angiotensin II causes contraction of the arteriolar and renal VASCULAR SMOOTH MUSCLE, leading to retention of salt and water in the KIDNEY and increased arterial blood pressure. In addition, angiotensin II stimulates the release of ALDOSTERONE from the ADRENAL CORTEX, which in turn also increases salt and water retention in the kidney. Angiotensin-converting enzyme also breaks down BRADYKININ, a powerful vasodilator and component of the KALLIKREIN-KININ SYSTEM.	Renin-Angiotensin-Aldosterone System,Renin Angiotensin Aldosterone System,Renin Angiotensin System,System, Renin-Angiotensin,System, Renin-Angiotensin-Aldosterone
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D004039	Diet, Sodium-Restricted	A diet which contains very little sodium chloride. It is prescribed by some for hypertension and for edematous states. (Dorland, 27th ed)	Diet, Low-Salt,Diet, Low-Sodium,Diet, Salt-Free,Diet, Low Salt,Diet, Low Sodium,Diet, Salt Free,Diet, Sodium Restricted,Diets, Low-Salt,Diets, Low-Sodium,Diets, Salt-Free,Diets, Sodium-Restricted,Low-Salt Diet,Low-Salt Diets,Low-Sodium Diet,Low-Sodium Diets,Salt-Free Diet,Salt-Free Diets,Sodium-Restricted Diet,Sodium-Restricted Diets
D004151	Dipeptides	Peptides composed of two amino acid units.	Dipeptide
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004656	Enalapril	An angiotensin-converting enzyme inhibitor that is used to treat HYPERTENSION and HEART FAILURE.	Enalapril Maleate,MK-421,MK421,Renitec,Renitek,MK 421,Maleate, Enalapril
D000450	Aldosterone	A hormone secreted by the ADRENAL CORTEX that regulates electrolyte and water balance by increasing the renal retention of sodium and the excretion of potassium.	Aldosterone, (+-)-Isomer,Aldosterone, (11 beta,17 alpha)-Isomer