velocities in the forward and reverse directions was 54.5: 1 , somewhat lower than that previously reported (McQuate & Utter, 1959). Product-inhibition experiments with a non-saturating concentration of the constant substrate showed that in every case competitive inhibition occurs. This is consistent with a rapidequilibrium random Bi Bi mechanism for the reverse reaction, a similar mechanism to...

Background. Previous studies have shown that global left ventricular function is depressed after myocardial infarction. However, little is known about the effects of myocardial infarction on contractility and the passive-elastic properties of residual myocardium. Methods and Results. We evaluated isometric function and passive myocardial stiffness in isolated, noninfarcted left ventricular papi...

Electrochemical biosensors that combine high selectivity of biochemical affinity with precise electrochemical detection are one the most necessary and powerful tools for assessing environmental pollution. This review addresses assess pollutant toxicity. using enzyme activity inhibition, DNA, whole cells, cytochrome P450 will be introduced, their advantages applications discussed, trends challen...

BACKGROUND Plasma aldosterone levels are elevated in patients with chronic heart failure (CHF) taking angiotensin-converting enzyme (ACE) inhibitors. Elevated aldosterone levels may reflect incomplete inhibition of the vascular converting enzyme during long-term ACE inhibition. We simultaneously measured plasma aldosterone levels and the degree of inhibition of the vascular converting enzyme in...

BACKGROUND AND PURPOSE The aim of the study was to selectively examine the effects of converting enzyme inhibition on the large brain arteries by using concomitant inhibition of carbonic anhydrase to cause severe dilatation of mainly parenchymal resistance vessels. METHODS Cerebral blood flow was measured using the xenon-133 injection technique in three groups of Wistar rats either during car...

To determine the contribution of kidney-derived renin and angiotensin converting enzyme to circulating and tissue levels of angiotensin peptides, we measured angiotensin (Ang)-(1-7), Ang II, Ang-(1-9), and Ang I in plasma, kidney, lung, heart, aorta, brown adipose tissue, adrenal, pituitary, and brain of five groups of male Sprague-Dawley rats: control rats, rats given the converting enzyme inh...

Hypertension and diabetes mellitus are strongly associated conditions from epidemiologic, genetic, and pathophysiologic points of view. The prevalence of hypertension is high in patients with diabetes, and, conversely, many patients with essential hypertension are glucose intolerant. Proteinuria appears in 40-50% of patients with insulin-dependent diabetes mellitus and 20-30% of patients with n...

Background Chronic treatment with high doses of angiotensin-converting enzyme (ACE) inhibitors prolongs survival after myocardial infarction. Since the plasma reninangiotensin system (RAS) is not consistently activated in the chronic phase after myocardial infarction, the beneficial effects of ACE inhibition have been attributed, in part, to inhibition of an activated tissue RAS. However, a rel...

The adaptive fermentation of galactose by yeast is inhibited by fluoride and azide. At sufficiently low concentrations, however, it is stimulated. From a mathematical analysis, using the known fact that fluoride inhibits the enzymes enolase and adenosinetriphosphatase, it is possible to infer the existence of such stimulation. Conditions for this effect are derived which relate the sensitivitie...