Biomaterial Database

Response of the renin-aldosterone system and antidiuretic hormone to oral water loading and hypertonic saline infusion during and after pregnancy. 1982

M B Vaklotton, and J M Davison, and A M Riondel, and M D Lindheimer

Amongst the man physiological changes in human pregnancy are the sustained stimulation of the renin-angiotensin system and a decreases in plasma osmolality (Posm). In this study the effect osmolar and water loading on the renin-angiotensin system and arginine vasopressin (AVP) secretion has been tested in seven women during the third trimester and again 8-10 weeks after delivery. Pregnant women had markedly increased plasma renin substrate (PRS), plasma renin activity (PRA) and plasma renin concentration (PRC) values as well as aldosterone levels when compared to their post-partum values. Osmolar loading with intravenous infusion of hypertonic saline resulted in a decrease in PRA and aldosterone levels both during and after pregnancy but even at the end of the infusion the pregnant women still had values greater than the pre-infusion levels obtained post-partum. Surprisingly, oral water loading also significantly decreased PRA and aldosterone levels in pregnancy, possibly related to the redistribution of extracellular fluid centrally when the pregnant women were in left lateral recumbency. Despite the decreased basal Posm of pregnancy, urinary AVP increased and decreased appropriately during osmolar and water loading. Exact characterisation of the resetting of the threshold for AVP secretion in pregnancy awaits the development of a reliable radioimmunoassay for the determination of AVP in human pregnancy plasma.

UI	MeSH Term	Description	Entries
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011263	Pregnancy Trimester, Third	The last third of a human PREGNANCY, from the beginning of the 29th through the 42nd completed week (197 to 294 days) of gestation.	Pregnancy, Third Trimester,Trimester, Third,Last Trimester,Last Trimesters,Pregnancies, Third Trimester,Pregnancy Trimesters, Third,Third Pregnancy Trimester,Third Pregnancy Trimesters,Third Trimester,Third Trimester Pregnancies,Third Trimester Pregnancy,Third Trimesters,Trimester, Last,Trimesters, Last,Trimesters, Third
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
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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
D001127	Arginine Vasopressin	The predominant form of mammalian antidiuretic hormone. It is a nonapeptide containing an ARGININE at residue 8 and two disulfide-linked cysteines at residues of 1 and 6. Arg-vasopressin is used to treat DIABETES INSIPIDUS or to improve vasomotor tone and BLOOD PRESSURE.	Argipressin,Vasopressin, Arginine,Arg-Vasopressin,Argipressin Tannate,Arg Vasopressin
D012462	Saline Solution, Hypertonic	Hypertonic sodium chloride solution. A solution having an osmotic pressure greater than that of physiologic salt solution (0.9 g NaCl in 100 ml purified water).	Hypertonic Saline Solution,Hypertonic Solution, Saline,Sodium Chloride Solution, Hypertonic,Hypertonic Saline Solutions,Hypertonic Solutions, Saline,Saline Solutions, Hypertonic,Sodium Chloride Solutions, Hypertonic,Saline Hypertonic Solution,Saline Hypertonic Solutions,Solution, Hypertonic Saline,Solution, Saline Hypertonic,Solutions, Hypertonic Saline,Solutions, Saline Hypertonic
D012965	Sodium Chloride	A ubiquitous sodium salt that is commonly used to season food.	Sodium Chloride, (22)Na,Sodium Chloride, (24)NaCl