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)

Although the role of renin in hypertension continues to be incompletely defined, recent progress in the chemistry of renin has been considerable. Extensive purifications of hog kidney renin and the renin-like mouse submaxillary gland enzyme have been achieved. Various inhibitory peptides based on tetradecapeptide renin substrate have been useful in renin kinetic studies and in renin affinity chromatography. Classification of renin as an acid protease results from its marked inhibition by pepstatin and from the discovery that free carboxyl at the active site is essential for activity in human and hog kidney and mouse submaxillary gland enzymes. The presence of pseudorenin in all tissues has limited the use of model peptides as renin substrates in plasma and crude tissue extracts, since the proteolytic properties of the two enzymes are nearly identical. The existence of renin in multiple, chromatographically separable forms has been known. More recently inactive forms have been found in plasma, amniotic fluid, and hog and rabbit kidneys. Prolonged storage or treatment with acid, trypsin, or pepsin causes activation; in some instances the conversion is from a higher than normal molecular weight. The implications of these findings with respect to the renin-angiotensin system need much further investigation.
 ...
PMID:New developments in our knowledge of the chemistry of renin. 1 50

1 (t-Butyl-amino-3-ol-2-propyl) oximino-9 fluorene is a new beta2-adrenoceptor blocking agent with a pA2 of 9.23+/-0.25 on isolated trachea. 2 It provokes hypertension in normotensive rats and does not prevent arterial hypertension in SHR rats, although it does prevent the renin secretion normally induced by isoprenaline infusion.
 ...
PMID:A potent new beta2-adrenoceptor blocking agent. 1 16

Six patients with permanent hypertension with renal artery stenosis were treated by conservative reparative surgery appart from one of them (unilateral nephrectomy) and were all seen again at the 8th month at the earliest in the absence of any anti-hypertensive therapy. Study of the renin-angiotensin system carried out on a normal sodium diet, after stopping all anti-hypertensive treatment for at least 15 days, was combined with the anti-hypertensive response under the influence of a beta-blocker. There were two types of response pre-operatively: firstly, with beta-blockers alone a normal blood pressure which remained normal postoperatively; the second group of patients remained hypertensive, requiring the addition of diuretics, and remained hypertensive after surgery. This response, although non-specific, would appear to represent an important element in assessing the curability of reno-vascular hypertension.
 ...
PMID:[The renin-angiotensin-aldosterone system in hypertensive subjects. III- The use of beta-blockers in reno-vascular hypertension (author's transl)]. 2 Jun 2

Several experimental observations accumulated during recent years have suggested an active participation of the sympathetic system in the pathogenesis and maintenance of hypertension in various experimental models of hypertension. The evaluation of sympathetic tone by various indirect means in human hypertension has also revealed that the sympathetic system plays an important role in the maintenance of hypertension in a subgroup of the human hypertensive population. The study of circulating catecholamines, which appears to be the best and most reliable indirect means to evaluate the sympathetic activity in the human, at present, has indicated that 25 to 40 per cent of patients with essential hypertension are characterized by higher basal circulating catecholamines and by a higher sympathetic reactivity in response to postural changes. These hyperadrenergic patients are also characterized by a higher heart rate, heart contractility, cardiac index and probably by higher plasma renin activity. The identification of these patients as a separate entity is desirable since it is possible that the evolution of the hypertensive disease and the response to therapy differ in this group of patients. The study of these patients could lead to a better understanding of the mechanisms underlying the pathogenesis of cardiovascular complications and to the development of more rational and efficient therapeutic approaches.
 ...
PMID:The sympathetic system in hypertension. 2 13

1. Two main physiopathological approaches to the treatment of hypertension are discussed, the first based on renin profiling and the second on haemodynamic measurements. 2. Reduction in plasma renin activity does not appear to be a clinically important mechanism in the hypotensive effect of beta-adrenergic blockers and of alpha-methyldopa. In particular, alpha-methyldopa has been found equally effective as a hypotensive agent both in normal renin and in low renin hypertensive patients. 3. Diuretics are certainly possessed of a renin-stimulating action, but in most patients this action does not obscure the hypotensive effect of these drugs. 4. Responders and non-responders to the hypotensive activity of beta-adrenergic blockers do not differ among them in their control haemodynamics.
 ...
PMID:Considerations on physiopathological approaches to the treatment of hypertension. 2 89

The influence of the dosage or duration of treatment on the incidence and severity of clonidine withdrawal responses was examined in normotensive rats. Clonidine (0.01 or 0.1 mg/kg i.m.) was administered either in single doses, or twice daily for 3 days or 3 weeks. Rats were then anesthetized and arterial catheters were inserted. Significant overshoots in blood pressure and heart rate, reaching peak values 16 to 26 hr after the last injection, occurred in all clonidine-treated rats, but in no control rats. The overshoots after single injections of clonidine were as great as those after suspension of sustained treatment. Moreover, withdrawal responses were as great after the low dose as they were after the 10-fold greater dose. Only plasma renin activity showed a significantly greater elevation during withdrawal of the high dose of clonidine. Since ganglionic blockade reduced blood pressures and heart rates to the same levels in rats with clonidine withdrawal hypertension as in control rats, the withdrawal overshoots appear to be nervously mediated. Neither the dosage nor the duration of treatment could be shown to determine the magnitude of the response to withdrawal of clonidine.
 ...
PMID:Withdrawal of clonidine: effects of varying dosage or duration of treatment on subsequent blood pressure and heart rate responses. 2 15

Sequential changes in plasma renin activity and urinary aldosterone and noradrenaline were assessed in eight patients with severe hypertension after minoxidil had been added to their treatment. Doses of 2.5--27.5 (mean 12.5) mg/day reduced the mean blood pressure from 166/113 +/-6/2 mm Hg to 124/88+/-4/2 mm Hg in one week. Plasma renin activity and urinary aldosterone and noradrenaline increased twofold to threefold initially but returned to baseline values within two to three weeks and remained unchanged during a mean follow-up of 5.1 months. Beta-blocking drugs were then withdrawn slowly in six patients without adverse effects, though blood pressure and heart rate increased in three patients, who required minimal doses of beta-blockers. Plasma renin activity and urinary aldosterone and noradrenaline did not change significantly after beta-blockade had been stopped. We conclude that the need for beta-blockade is greatly reduced with long-term minoxidil treatment and that it may be unnecessary in some patients.
 ...
PMID:Need for beta-blockade in hypertension reduced with long-term minoxidil. 2 11

In a field study comprising 678 patients with arterial hypertension efficacy and tolerance of the stable combination VKB 105 consisting of 10 mg Pindolol (Visken) and 5 mg Clopamid (Brinaldix) were investigated. Treatment with 1--2 tablets of VKB per day resulted in a successful therapy in 94% of all patients corresponding on the average to a reduction in blood pressure to 145/85 mm Hg within 14 days. In mean arterial pressures ranging between 120 and 170 mm Hg a positive linear relationship between the individual initial value and the hypotensive effect of the combination could be observed. A controlled omission trial disclosed qualitatively the respective contribution to the effect of the two components Pindolol and Clopamid. With a systematic case control of the serum potassium under the combined therapy with VKB 105 and during a monotherapy with Clopamid and antihypokalaemic effect of Pindolol could be demonstrated diminishing the tendency for potassium loss. The result revealed a far-reaching potassium neutrality of diuresis-depending stimulation of renin by the beta-receptor blocker. In 61 patients altogether subjective side-effects could be recorded, such as vertigo (5%), palpitations (2.8%), fatigue (2%), insomina (1.9%), nausea (1.7%) and vomiting (0.8%). Laboratory controls gave no indication for clinically relevant changes.
 ...
PMID:[A field study with the combination of Pindolol and Clopamid in antihpertensive therapy (author's transl)]. 3 34

Recent research shows that the renin-angiotensin-aldosterone axis either maintains or causes some or all of the high blood pressure of most patients and demonstrates anew that renin-sodium profiling defines this involvement. Performed with a serum potassium measurement, this now reliable test is useful for primary screening and then, in conjunction with renal vein renin studies or an aldosterone profile, for diagnosis or exclusion of surgically curable renovascular or adrenocortical hypertensions. For the remaining majority with essential hypertension, renin profiling exposes the relative participation of either vasoconstriction or volume factors, thereby guiding simpler, more specific, and predictably effective antirenin or antivolume treatments. Renin profiling identifies those in whom treatment should begin with a beta-blocker as opposed to a diuretic while not infrequently also providing baseline information about severity and prognosis in individual patients.
 ...
PMID:Renin profiling for diagnosis and treatment of hypertension. 3 92

The condition of the sympatheticoadrenal system and blood renin activity were studied in healthy children and in children suffering from primary arterial hypertension and treated with beta-blocking agents (Obzidan, Visken). A hypotensive effect was noted in the group of patients suffering from primary arterial hypertension with a high blood renin level and increased excretion of catecholamines in the urine.
 ...
PMID:[State of the sympathetic-adrenal system and renin activity in the blood in children with primary arterial hypertension in the process of beta-blockader treatment]. 3 7


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