0000000000054444
AUTHOR
U. Walter
Studies on erythrocyte acetylcholinesterase in essential hypertension.
There is accumulating evidence that acetylcholinesterase (AChE might be involved in the transport of sodium across biological membranes. Consequently, because in primary hypertension abnormalities in the transport of sodium by red blood cells have been documented. AChE activities were measured in hemoglobin-free red-blood-cell membranes of patients with essential hypertension. In the absence of any effectors, the Michaelis constant of AChE for acetylcholine (Km) was 1.57 . 10(-5) mol/l, both in normotensives and in hypertensives. Sodium inhibited AChE at low substrate concentrations, whereas the enzyme was activated by sodium at moderate and high substrate levels. With increasing sodium, th…
Untersuchungen über die pH-Abhängigkeit, Hemmbarkeit und Reaktivierbarkeit von Angiotensin II-amid-spaltenden Aminopeptidasen menschlicher Erythrozyten
In menschlichen Erythrozytenfraktionen (hamoglobinfreie Erythrozytenmembranen; membranfreies Hamolysat; durch DEAE-Cellulose von Hamoglobin befreite Enzym-Protein-Fraktion) wurde mit Hilfe eines NADH-abhangigen optischen Tests mit Asparaginyl1-Angiotensin II-amid als Substrat die Aminopeptidaseaktivitat untersucht.
Effects of a Brief Web-Based "Social Norms"-Intervention on Alcohol, Tobacco and Cannabis Use Among German University Students: Results of a Cluster-Controlled Trial Conducted at Eight Universities.
Background and Aim: “Social norms” (SN)-interventions are aimed at changing existing misperceptions regarding peer substance use by providing feedback on actual norms, thereby affecting personal substance use. It is unknown whether SN-intervention effects previously demonstrated in US students can be replicated in German students. The aim of the INSIST-study was to examine the effects of a web-based SN-intervention on substance use.Design: Cluster-controlled trial.Setting: Eight Universities in Germany.Participants and Measurements: Students were recruited at four intervention vs. four delayed intervention control Universities. 4,463 students completed baseline, 1,255 students (59% female) …
ATPase Aktivität und Natriumtransport an Erythrocyten bei essentieller Hypertonie
Die Geschwindigkeitskonstante des „Gesamt“ Natriumefflux aus Erythrocyten war bei Patienten mit essentieller Hypertonie im Vergleich zu einem normotonen Kontrollkollektiv erniedrigt und beruhte auf einem verminderten „Ouabain-abhangigen“ (aktiven) Natriumtransport. Die Geschwindigkeitskonstanten des „Ouabain-unabhangigen“, des „Ouabain-unabhangigen Furosemid-abhangigen“ und des „Ouabain-unabhangigen Furosemid-unabhangigen“ Natriumefflux waren bei Hypertonikern und Normotonikern gleich. Ouabain hemmte bei beiden Kollektiven den Natriumefflux um rund 74%, Furosemid um weitere 13%. Der verminderte aktive Natriumtransport an Erythrocyten essentieller Hypertoniker ging mit einer erniedrigten Na-…
Inhibition of molybdenum blue formation by ATP.
Molybdenum blue formation was not affected by the presence of ATP up to a concentration of 1.2 muM/l. At higher concentrations the color development was inhibited relative to ATP concentration, finally reaching complete inhibition. Auto-hydrolysis of ATP was found at a rate of 1.4%/h. An exact determination of inorganic phosphate in the presence of easily hydrolyzed phosphate esters requires the measurement of extinction at fixed time intervals and extrapolation back to time zero.
Angiotensin II-Stoffwechsel bei Angiotensininfusion und bei Kochsalzentzug
1. Bei funf normotonen Probanden wurde im arteriellen und venosen Plasma des Unterarms vor und nach diatetischem Salzentzug sowie vor und wahrend Infusion von Angiotensin II-amid Angiotensin II (A II) und der Angiotensinmetabolit Angiotensin (3–8)-Hexapeptid (H) nach dunnschichtchromatographischer Trennung radioimmunologisch bestimmt.
Tagesprofile von Plasmaaldosteron,-Cortisol, -Renin, -Angiotensinogen und -Angiotensinasen bei Normalpersonen
Plasma cortisol and renin were estimated in 1 h intervals, plasma aldosterone, angiotensinogen and angiotensinases in 3 h intervals over periods of 24 h in six normal volunteers (age 20-26) under control conditions and subsequently under suppression of ACTH release by dexamethasone. Highest cortisol levels were found around 7 a.m., minimum levels between 9 p.m. and 1 a.m. Dexamethasone reduced cortisol to constantly low concentrations. Aldosterone was highest around 4 a.m. under control conditions and under dexamethasone, and showed lowest concentrations between 4 and 10 p.m. There were no significant differences between mean aldosterone concentrations at corresponding time points of the co…