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

In gravid women who are destined to develop pregnancy-induced hypertension (PIH), normal pregnancy-associated refractoriness to the pressor effects of administered angiotensin II (A-II) is lost several weeks before the onset of hypertension. From a study of the determinants of A-II pressor responsiveness in normal gravid women, it appears likely that the loss of resistance to A-II is principally unrelated to plasma renin activity or to plasma A-II levels. However, it recently has been shown that the vascular refractoriness to A-II in normal women can be reduced significantly by the administration of the prostaglandin synthetase inhibitors, indomethacin or aspirin. In seven women who had developed PIH and who had lost their refractoriness to A-II, the infusion of 5alpha-pregnan-3,20-dione (5alpha-DHP) was associated with restoration of refractoriness to the pressor effects of A-II. Moreover, in five normotensive gravid women beyond 28 weeks' gestation in whom the refractoriness to A-II was reduced by the administration of indomethacin, the intravenous infusion of 5alpha-DPH was associated with restoration of refractoriness to the pressor effects of A-II. These observations are consistent with the view that a progesterone metabolite(s) may be important in the maintenance of normal blood pressure during human pregnancy.
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PMID:Modification of vascular responsiveness to angiotensin II in pregnant women by intravenously infused 5alpha-dihydroprogesterone. 9 97

During the public information programme, "Frankfurter Gesundheitstage" 1990 (Frankfurt Days for Health), organised by the Frankfurt Public Health Office, informations on healthy lifestyle and prevention of diseases were available, as well as a screening programme for cardiovascular diseases. 1,875 persons took part in that screening programme. Their total cholesterol, blood pressure and body weight were measured; they were asked about their age and body weight, activities in sports, smoking behaviour, medications, and their personal and family history for cardiovascular diseases. After accounting for sex and age, the results were compared with the representative epidemiological data of the DHP-Surveys, as well as other representative data of Germany. Body mass index was lower than expected; the heavily obese underrepresented. Mean of serum-cholesterol and blood pressure were comparable with the DHP-Survey, as well as the prevalence of hypercholesterolaemia. The prevalence of hypertension was less than expected. Smokers were underrepresented; in women aged greater than 40 years the prevalence of smoking did not differ from the representative data, and in women aged 30-50 years the prevalence of heavy smokers was much higher than expected. Our data are not representative: participation was voluntary, and it may be supposed that especially people who take care of their health and thus may exhibit less risk factors than others took part in the programme. Direct conclusions from our data on the prevalence of cardiovascular risk factors of the Frankfurt population are hence not possible. It may be speculated, however, that the extremely high lung cancer mortality of women in Frankfurt can be explained by the high prevalence of heavily smoking women.
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PMID:[Cardiovascular risk factors in participants of screening procedures in the framework of the Frankfurter Health Days 1990--comparison with representative screenings]. 155 87

We measured the synthesis of progesterone (P) from pregnenolone and its conversion into 20 alpha-dihydroprogesterone (20 alpha-DHP) in placentas obtained from 12 patients with severe pregnancy-induced hypertension and from 24 normotensive patients. There was no significant difference between placentas from hypertensive and normotensive patients with respect to mitochondrial 3 beta-hydroxysteroid dehydrogenase: delta 5-isomerase activity both before and after labor, indicating that the capacity of this organ to synthesize P remains unchanged during labor in both groups of patients. There was a significant (p less than 0.05) difference in 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSDH) activity in placental supernatants obtained from normotensive patients before (853.58 +/- 293 pmoles of 20 alpha-DHP/mg of protein/hr) and after (1,156.66 +/- 280 pmoles/mg of protein/hr) labor. In contrast, 20 alpha-HSDH activity in placental supernatants obtained from hypertensive women before (644.30 +/- 236 pmoles/mg of protein/hr) and after (697.17 +/- 524 pmoles/mg of protein/hr) labor was not significantly different. As a consequence, the endogenous 20 alpha-DHP concentration, which was significantly increased after labor in placentas from normotensive women, remained unchanged in placenta from women with pregnancy-induced hypertension. These results indicate that premature activation of the P to 20 alpha-DHP pathway causing "in situ" P withdrawal does not seem to be an adequate explanation for the increased contractility and the tendency to preterm labor commonly exhibited by patients with pregnancy-induced hypertension
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PMID:Synthesis and catabolism of progesterone in placentas from normotensive and severely hypertensive patients before and after parturition. 694 91

We report a 46-year-old man with primary aldosteronism presenting hypokalemia, periodic paralysis and hypokalemic myopathy whose clinical course paralleled with the dosage of benidipine hydrochloride, a dihydropyridine calcium channel blocker (DHP-CCB), administered for the treatment of hypertension. To see relations between DHP-CCB and episodes of motor weakness in patients with primary aldosteronism, we surveyed retrospectively the history of motor weakness and anti-hypertensive drugs in 14 consecutive cases with primary aldosteronism in our institute. Five patients out of 11 cases (45.5%) who had received DHP-CCB experienced muscle weakness, however, the rest of three patients receiving other anti-hypertensive drug had not experienced weakness. Though, less attention has been paid as thiazide diuretics, it is reported that DHP-CCB also induces hypokalemia through several mechanisms. However, the occurrence of motor weakness by DHP-CCB is very rare. Our results show that primary aldosteronism should be taken into account when we encounter patients manifesting episodic motor weakness by the use of DHP-CCB.
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PMID:[A case of primary aldosteronism presenting hypokalemic myopathy induced by benidipine hydrochloride; a dihydropyridine calcium channel blocker]. 1100 26

In September, 2000, the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health called an early halt to the amlodipine arm of the African American Study of Kidney Disease and Hypertension (AASK) trial after careful deliberation by an independent data and safety monitoring board. An interim analysis of the AASK at 3 years revealed a renoprotective effect of the angiotensin-converting enzyme inhibitor ramipril as compared to the dihydropyridine calcium channel blocker (DHP-CCB) amlodipine in patients with mild to moderate renal insufficiency. This differential effect was independent of the blood pressure (BP) levels reached and was evident in proteinuric patients and suggestive in patients with baseline proteinuria < 300 mg/d, but was not conclusive. The AASK trial data suggest that DHP-CCBs should be used cautiously in the presence of mild to moderate renal insufficiency. Judgment should be reserved for the use of other CCBs, such as verapamil or diltiazem, since these are fundamentally different CCBs with the potential for a different impact on hypertensive nephrosclerosis. The blinded observation period for AASK will be completed at the end of September, 2001, at which time additional, clinically useful information is expected to become available. (c)2001 Le Jacq Communications, Inc.
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PMID:The African American Study of Kidney Disease and Hypertension (AASK): new findings. 1149 55

Even well-conducted randomized controlled trials can only reduce uncertainty, not eliminate it. The trials presented in this article all have gaps, and like many studies, some raise more questions than answers. A summary of the current trials, however, can be presented as follows. For patients with essential hypertension who are at high risk for cardiovascular disease, the use of diuretic therapy (excluding simultaneous use of ACE or CCB) resulted in outcomes at least equivalent to the use of either ACE or CCB without diuretics. Naturally, the dilemma for clinicians is that these drugs are most often used in combination with thiazide diuretics, as indicated by the RENAAL trial where 80% of ARB were used with diuretics in patients with type II diabetes and known nephropathy. The increased risk of heart failure observed with ACE and CCB in that trial may be relevant only to patients in whom diuretics were not also used. The study does raise important awareness, however, that ACE or CCB use without diuretic therapy is no better than diuretic therapy, and may be associated with higher risk of certain outcomes. A substantial number of patients with essential hypertension might achieve adequate blood pressure control with diuretic monotherapy. If so, that certainly has important implications for the cost of medical care in this country. For African Americans with essential hypertension, ACE may have advantages as a component of therapy in comparison with CCBs or beta-blockers, although diuretics should probably be the cornerstone of therapy for them and supported by the Seventh Joint National Committee. For patients with proteinuric renal disease, whether associated with diabetes or hypertension, it should be considered inappropriate to use DHP CCB as monotherapy in any setting, whether as part of a clinical trial or in clinical practice. These drugs should not be considered as ethical placebo arms in trials, most especially in diabetic nephropathy, nor should they be used without an ACE or ARB in patients with proteinuric renal disease in the absence of documented contraindications or intolerance to ACE, ARB, or non-DHP CCB (which are now considered second-line agents for proteinuric renal disease, and are acceptable placebo or comparison arms in clinical trials). For patients with type I diabetes, ACE remain the cornerstone of therapy. Because of recent RENAAL and IDNT trial results, the greatest benefit for slowing progression of renal disease in type II diabetic nephropathy now belongs to ARBs. In contrast, however, the HOPE trial showed that ACE, specifically ramipril, had the greatest evidence for prevention of cardiovascular outcomes in patients with renal insufficiency, regardless of diabetic status. Cardiovascular outcomes were secondary end points in the RENAAL and IDNT trials, and with the exception of heart failure for losartan, no benefits on cardiovascular outcomes were statistically significant. Progression of renal disease has only been studied in a relatively small cohort of Israeli patients comparing enalapril with nifedipine. These gaps lead to a classic dilemma in medical decision-making. Because evidence has shown that patients with elevated serum creatinine (greater than or equal to 1.4 mg/dL) are just as likely to die from cardiovascular disease as they are to reach end-stage renal disease, which outcome should be the focus for clinicians, or for researchers? Using a strictly evidence-based approach, this question can only be answered by yet another large, long, randomized, controlled trial. Given the similarity of actions between the ARB and ACE, it is likely there is considerable overlap of both benefits and side-effects between the two, although ARB may have a lower incidence of cough and hyperkalemia. The decision of which antihypertensive agents to use will have to be tailored carefully to the needs of the patient and careful consideration of both medical and economic factors. Regardless of the choice between an ACE or ARB, however, post hoc analysis of clinical trials [21,47] and observational data clearly indicate that patients with chronic kidney disease, even if considered mild (ie, serum creatinine greater than or equal to 1.4 mg/dL) are at significantly greater risk of cardiovascular morbidity and mortality compared with those with better kidney function. As stated in a recent review by the authors of the HOPE trial [50], "the frequent practice of withholding ACE [or ARB] in patients with mild renal insufficiency is unwarranted," because not only are these patients precisely those who might benefit most from their use, but safety and tolerability are generally excellent. Based on the results of the AASK trial, the authors add the same for the use of ACE inhibitors in African Americans.
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PMID:What have we learned from the current trials? 1487 Oct 59

The prototype 1,4-dihydropyridine (1,4-DHP) nifedipine, indicated for the management of hypertension and angina pectoris, has drawbacks of rapid onset of vasodilating action and a short half-life. Several newer analogues have been designed to offset these problems and these include mebudipine and dibudipine. These analogues contain t-butyl substituents that have been selected to alter the fast metabolism without altering pharmacological activity. In this study, the metabolism of mebudipine and dibudipine by isolated rat hepatocytes has been investigated. These compounds were extensively metabolized in 2 h by oxidative pathways, analogous to those known for nifedipine, and by O-glucuronidation after hydroxylation of the t-butyl substituents. The in-vitro half-lives of mebudipine (22 +/- 7.1 min) and dibudipine (40 +/- 9.8 min) were significantly longer than that of nifedipine (5.5 +/- 1.1 min), which was investigated in parallel in this study. These newer 1,4-DHPs address the problem of the short half-life of nifedipine and have potential for further development in view of their comparable potency to nifedipine.
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PMID:Metabolism of the dihydropyridine calcium channel blockers mebudipine and dibudipine by isolated rat hepatocytes. 1552 56

Although end-stage renal disease (ESRD) currently affects only a small percentage (<0.2%) of the US population, its precursor, the mild and moderate forms of chronic kidney disease (CKD), affects 11% of the population, with significant growth in both ESRD and CKD anticipated in the rapidly aging US population. The primary diagnoses in the majority of ESRD patients are diabetes and hypertension. Results of clinical studies demonstrate that the level of proteinuria and sympathetic activation contribute to the progression of CKD to ESRD. There are sufficient clinical data to demonstrate that the dihydropyridine calcium channel blocker (DHP CCB) class of antihypertensives such as amlodipine and nifedipine, although effective in reducing systemic hypertension, lack activity in reducing proteinuria or attenuating sympathetic activity. Experimental studies and a limited number of clinical studies suggest that non-DHP CCBs, including verapamil and diltiazem, have a mechanism of action that differs from DHP CCBs. Non-DHP CCBs could potentially attenuate sympathetic activity and reduce protein excretion in patients with CKD.
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PMID:Calcium channel blockers and the kidney. 1585 Jul 65

Calcium channel blockers are widely used in therapy for hypertension and angina pectoris, and among these blockers some 1,4-dihydropyridines (e.g. amlodipine, nitrendipine and nifedipine) have had widespread clinical use. In this work we investigated the vascular effects of four bis-1,4-dihydropyridines (bis-DHPs: 01-04), structurally related to nifedipine, in which a second 1,4-dihydropyridinic moiety was incorporated in the corresponding arylic moiety in para and meta position. Of these four bis-DHPs, the meta regioisomers (bis-DHP-03 and bis-DHP-04; 0.01-3.16 mg kg(-1)) and nifedipine induced a greater decrease on diastolic and systolic blood pressure than the para isomers (bis-DHP-01 and bis-DHP-02), as shown in two experimental models: normotensive and spontaneously hypertensive rats. Complementarily, bis-DHPs action was examined in intact and endothelium-denuded rat aorta, depolarized by KCl [80 mM] in one group and stimulated by noradrenaline (1 x 10(-7) M) in another and the corresponding IC(50) values were obtained (1.5 x 10(-6)-2. 4 x 10(-7)M). Later, the relaxing action of bis-DHP-03,04 and nifedipine on the contraction evoked by Ca(2+) in K(+)-depolarized rat aorta was analyzed and the corresponding EC(50) values for the meta isomers and nifedipine were obtained. The results showed a concentration dependent vasodilating activity in both KCl precontracted and noradrenaline stimulated aorta rings. The apparent order of potency with and without endothelium in both experimental models was nifedipine >bis-DHP-04 >bis-DHP-03. The cumulative concentration-effect curves for Ca(2+) in the presence of the bis-DHPs tested show the same potency order. Unlike nifedipine, the tested compounds are not photosensitive, which makes them more attractive in therapy for hypertension related diseases.
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PMID:Vasodilator effects of bis-dihydropyridines structurally related to nifedipine. 1701 93

Self blood pressure measurements (home BP) and/or ambulatory BP measurements are recommended in mild to moderate hypertension (140/90 - 179/109 mmHg) in order to confirm sustained hypertension and identify white coat and masked hypertension. The evaluation of target organ damages (TOD) has to be integrated in cardiovascular risk estimate and taken into account in the management of hypertensive patients. Beside echocardiography, there is a place for the screening of microalbuminuria in non diabetic hypertensive patients, but these investigations should not be performed systematically. Arterial stiffness evaluation and carotid intima-media thickness quantification are not yet recommended. Cardiovascular risk (CV risk) estimate plays a pivotal role in the therapeutic decision and strategy. The cardiovascular risk grade is based on [1] the list of cardiovascular risk factors (same list AFSSAPS recommendations on dyslipidemia), [2] the presence or absence of TOD and [3] cardiovascular complications: "low", "medium", and "high" CV risk. Lifestyle modifications are recommended in all hypertensive patients. Five antihypertensive drugs are recommended for first line therapy: beta-blockers, thiazide diuretics, ACEIs, ARA II and CCBs (and fixed low dose combinations with AFSSAPS agreement for first line). In order to initiate the treatment, Evidence-based therapy (according to clinical trials conducted in different clinical situations), certain comorbid conditions (compelling indications), efficacy and side-effects in a previous experience, and the cost are the determinants of the first choice. Most hypertensive patients require more than one agent to achieve target blood pressure and for second line therapy the recommended combinations are: betablockers-diuretics, ACEIs-diuretics, ARAII-diuretics, betablockers-CCBs (DHP), ACEIs-CCBs, ARA II-CCBs and CCBs-diuretics. The delay to establish a combination therapy depend on CV risk. The BP goals are those recommended by ESH-ESC 2003: BP<140/90 mmHg in all, BP<130/80 mmHg in diabetic patients and in patients with chronic renal failure. Beside lowering BP, the reduction in proteinuria <500 mg/24 h is a new goal in these high risk patients. These guidelines provide a tool for every day practice and applicability should be evaluated.
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PMID:[French as 2005-recommendations on the management of arterial hypertension]. 1740 53


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