Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of hydralazine (3 mg/kg) and the angiotensin I-converting enzyme (ACE) inhibitor captopril (SQ 14,225) (100 mg/kg) on mean arterial blood pressure, plasma renin activity, urinary volume and urinary Na+,K+, and aldosterone concentrations were examined in spontaneously hypertensive rats of the Okamoto and Aoki strain (SHR) after oral daily dosing for 2 weeks, 3 or 6 months. Captopril caused progressive cumulative reductions in blood pressure resulting in normalization of pressure after 6 months of dosing. Hydralazine also significantly reduced blood pressure but not to the level of normotensive rats of the Wistar-Kyoto strain (WKY). Reductions in heart size paralleled the changes in blood pressure, normalization of cardiac hypertrophy occurring after captopril but not hydralazine. Plasma renin activity increased approximately 2-3 fold after hydralazine and 15-fold after captopril. Neither hydralazine nor captopril had any consistent effects on 24-hr urine volume, urinary Na+,K+ or aldosterone excretion. These results indicate that chronic inhibition of ACE with captopril induces normalization of blood pressure in SHR, a normal-renin model of hypertension.
 ...
PMID:Effects of chronic treatment with captopril (SQ 14,225), an orally active inhibitor of angiotensin I-converting enzyme, in spontaneously hypertensive rats. 23

Purified peptidyl dipeptidase (angiotensin I converting enzyme or kininase II) from human lung or hog kidney is inhibited by commercially prepared plasma protein preparations, by human serum albumin and by the additive albumin stabilizer, acetyltryptophan. After the initial steps of purification, albumin was detected by immunodiffusion as a component in human lung peptidyl dipeptidase preparation. Fragment C of albumin (sequence 124-298) is a more potent inhibitor than the parent molecule (Ki = 1.7 X 10(-5)M). Reduction and carboxymethylation of five of the six S-S bridges in Fragment C yield the most potent noncompetitive inhibitor (Ki = 3 X 10(-6)M). Reduction of the sixth bridge raises the K1. This indicates that maintenance of the tertiary structure in Fragment C is of importance for the inhibition. Neither albumin nor Fragment C are substrates of the enzyme. Fragment C and its derivative also inhibit the inactivation of bradykinin by the purified human enzyme and by the peptidyl dipeptidase on the surface of intact cultured human endothelial cells.
Hypertension
PMID:Inhibition of human peptidyl dipeptidase (angiotensin I converting enzyme: kininase II) by human serum albumin and its fragments. 23 85

1. The response of arterial blood pressure, plasma renin activity and plasma aldosterone concentration to inhibition of angiotensin I converting enzyme (kininase II) with captopril has been studied in patients with severe, treatment-resistant, malignant hypertension. 2. Nine patients with a past history of severe hypertension, supine diastolic blood pressure greater than 120 mmHg before conventional antihypertensive therapy and resistant to conventional antihypertensive therapy were studied. 3. Captopril administration resulted in a marked decrease in arterial blood pressure and plasma aldosterone concentration and an increase in plasma renin activity. 4. Although arterial blood pressure remained significantly below the values observed during the control period, pressure did tend to increase again after 3 days. Addition of hydrochlorothiazide kept arterial pressure significantly below pretreatment control values.
 ...
PMID:Response of arterial blood pressure, plasma renin activity and plasma aldosterone concentration to long-term administration of captopril in patients with severe, treatment-resistant malignant hypertension. 39 84

We assessed the role of the renin-angiotensin system in the response of the renal circulation to restriction of sodium intake in 38 normal patients. Both saralasin (10 to 30 ng/kg/min), an angiotensin antagonist, and SQ 20881 (30 to 300microgram/kg), a converting enzyme inhibitor, induced a dose-related increase in renal blood flow (xenon 133 washout) only when the resin-angiotension system was activated by restriction of sodium intake to 10 MEq/day. Increasing doses of saralasin (100 to 1,000 ng/kg/min) reduced renal blood flow, presumably due to the angiotensin-like action of this partial agonist. The renal vascular response to SQ 20881 paralleled the endocrine response: An identical threshold dose (30 microgram/kg) increased renal blood flow and reduced plasma angiotensin II concentration, which fell despite a progressive rise of plasma renin activity. Plasma bradykinin concentration did not change in response to SQ 20881, which also blocks kininase II. Both agents also induced a small but consistent and statistically significant reduction in arterial blood pressure, which will be important in assessing the pathogenetic significance of a blood pressure reduction in patients with hypertension. This study indicates that angiotensin mediates the renal vascular response to restriction of salt intake in normal man and provides an approach to assessing the role played by angiotensin in the pathogenesis of functional renal disease.
 ...
PMID:Renal vascular response to interruption of the renin-angiotensin system in normal man. 59 39

Although there is impressive documentation linking severe hypertension to renal insufficiency, corresponding data for mild-to-moderate hypertension are only now starting to emerge. As a result, it is only now becoming evident that a much larger portion of the hypertensive population could be susceptible to drug accumulation owing to renal insufficiency. Angiotensin-converting enzyme (ACE) inhibitor therapy routinely requires dosage adjustment in the instance of renal insufficiency, as all currently marketed ACE inhibitors are renally eliminated. Such dosage adjustments are usually considered a way to minimize side effects and to limit the duration of any induced hypotension. Dosage adjustment is usually considered at creatinine clearance levels between 30 and 60 ml/min. This is somewhat problematic, as physicians generally rely on serum creatinine determinations to assess renal function, and serum creatinine values are notoriously poor predictors of actual creatinine clearance. This is particularly true in the elderly population, where a greater disparity between the serum creatinine and creatinine clearance commonly exists, with moderate renal insufficiency frequently going unrecognized. Thus, the development of other ACE inhibitors eliminated via renal/hepatic routes may prove to be advantageous in that dosage adjustments might not be required in the setting of declining renal function, whether age-related or not. Fosinopril, a new phosphorus-containing ACE inhibitor, is administered as a prodrug and is hydrolyzed to the pharmacologically active diacid, fosinoprilat.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Kinetics of angiotensin-converting enzyme inhibitors in renal failure. 128 26

Angiotensin-converting enzyme (ACE) inhibitors are established in the treatment of hypertension and heart failure; both conditions are complicated by resistance to insulin-mediated glucose disposal. The defect in essential hypertension is both tissue and pathway specific, i.e., confined to nonoxidative (glycogen synthetic) routes of intracellular glucose utilization in skeletal muscle, whereas heart failure and non-insulin-dependent diabetes mellitus (NIDDM) are associated with more widespread abnormalities of carbohydrate and lipid metabolism. Thus, the mechanisms of the insulin resistance in hypertension, NIDDM, and heart failure are fundamentally different, so metabolic responses to drug therapy may not be the same in all insulin-resistant states. There have been conflicting reports about the effects of ACE inhibitors on insulin sensitivity and glycemic control. A number of studies, both with captopril and with enalapril, have shown small increases in insulin sensitivity, and there is evidence that this is due to enhanced glucose uptake into skeletal muscle. The interpretation of these studies, however, is often compromised by poor trial design, lack of full placebo data, various indirect measurements of insulin sensitivity, and heterogeneous patient populations in whom the biochemical mechanisms of insulin resistance (and drug responses) may not be the same. Overall, there probably is a modest class effect of ACE inhibitors that enhances insulin-mediated glucose disposal; the mechanism of this effect is likely to be a combination of increased muscle blood flow, local renin-angiotensin system blockade, and elevated kinin levels.
 ...
PMID:Angiotensin-converting enzyme inhibitors and insulin sensitivity: metabolic effects in hypertension, diabetes, and heart failure. 128 42

Insulin resistance and hyperinsulinemia is now recognized in non-insulin-dependent diabetes, essential hypertension, obesity, atherosclerotic heart disease, dyslipidemia, heart failure, and in heavy smokers. Several mechanisms have been proposed to explain hyperinsulinemia, insulin resistance and its relationship to hypertension; reduced sodium excretion, activation of the sympathetic nervous system, increased activity of the sodium/hydrogen pump, and stimulation of cellular growth. Some of the nonpharmacological methods to control hyperinsulinemia are of benefit in the management of hypertension, most notably weight loss, exercise program, and reduced salt intake. High-fiber and reduced-protein diets also reduce hyperinsulinemia. Thiazide diuretics can result in insulin resistance, and insulin secretion may be inhibited, possibly associated with concomitant hypokalemia. beta-Blockers result in some reduction of glucose tolerance and mask some of the features of hypoglycemia. Angiotensin-converting enzyme (ACE) inhibitors and alpha-receptor blockers do not effect insulin resistance; probably the same is true for calcium antagonists. Although the effect on risk factors should not be discounted, it is the effect of treatment on hard end points, cerebrovascular accidents, myocardial infarction, or death that is most important. Evidence in hypertension is at present restricted to diuretics and beta-blocking drugs.
 ...
PMID:Hypertension and insulin resistance. 128 47

Angiotensin-converting enzyme (ACE) inhibitors are increasingly used to control hypertension although cough, sometimes severe enough to require discontinuance, is a well-described side effect of these drugs. Manufacturers' labeling indicates that this side effect occurs with a much lower frequency than is reported in the literature. This article describes the incidence of cough as a side effect of ACE inhibitors in a small inner-city practice and presents two reports of patients who required discontinuance of ACE inhibitors for this symptom. It is suggested that, consistent with the recent literature, the incidence of this symptom is more frequent than suggested by manufacturers' labeling, at least in this population.
 ...
PMID:Cough requiring discontinuance of angiotensin-converting enzyme inhibitors in an urban inner-city population. 129 95

Angiotensin-converting enzyme (ACE) inhibitors act by lowering the level of angiotensin II. The therapeutic benefits of these drugs and their potential side-effects therefore result from suppression of the physiological effects of angiotensin II. It is rational to prescribe an ACE inhibitor when the renin-angiotensin system is activated, as in renin-dependent essential hypertension, malignant hypertension and hypertension associated with heart failure. The beneficial effects of ACE inhibitor must be weighed against the special risks of renovascular hypertension: risk of renal artery thrombosis in case of unilateral stenosis and risk of renal failure if the stenosis is bilateral or affects a solitary kidney. In some situations the renin-angiotensin system is not directly involved in hypertension but may play a local haemodynamic role, as in some cases of primary or diabetic nephropathy. In such case the ACE inhibitors are thought to exert a protective effect. ACE inhibitors were reputed to be less effective in the elderly than in younger patients, but we now know that they can be prescribed with equal success in both instances to reduce peripheral resistance and improve regional blood flow as well as arterial compliance. Finally, ACE inhibitors can be prescribed, albeit with limited effectiveness, when the renin-angiotensin system is not activated, as in low renin hypertension and idiopathic hyperaldosteronism due to adrenal hyperplasia. They are ineffective in case of Conn's adenoma and contra-indicated in pregnant women.
 ...
PMID:[For which hypertensive patient should angiotensin-converting enzyme inhibitor be prescribed or forbidden?]. 129 38

Angiotensin-converting enzyme (ACE) inhibitors are now widely used as first-line treatment of essential hypertension. Their effectiveness is potentiated by a low-salt diet and, above all, by the simultaneous prescription of diuretics. When secondary hypertension is suspected, ACE inhibitors are a good pharmacological tool to study the renin-angiotensin system. Since activation of this system is the main mechanism responsible for renovascular hypertension, ACE inhibitors are very useful for diagnosis. Conversely, blood pressure is not influenced by ACE inhibitors in primary hyperaldosteronism because of the low plasma renin and angiotensin II levels. Pheochromocytoma activates the renin-angiotensin system, and ACE inhibitors combined with beta-blockers enable the hypertension to be controlled prior to surgical treatment of the tumour. Finally, ACE inhibitors can be used to explore the renin-angiotensin system in the experimental model of renovascular hypertension and therefore contribute to our knowledge of the complex pathophysiology of this most frequent type of secondary hypertension.
 ...
PMID:[Usefulness of converting enzyme inhibitors in the diagnosis of arterial hypertension]. 129 39


1 2 3 4 5 6 7 8 9 10 Next >>