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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The genetic and cultural heritability and intercorrelation of traits related to hypertension have been carried out in 98 Utah pedigrees (2,500 person) and 58 sibships with two or more hypertensive persons (131 hypertensive persons). Although none of these traits has been established as a marker for "sodium-sensitive hypertension," many of them are related at least indirectly to both electrolyte metabolism and risk of hypertension. Significant recessive monogenic effects and high total heritability (52-84%) were found for urinary kallikrein, high fat pattern index, intraerythrocytic sodium, Na-Li countertransport, and ouabain binding sites. Familial correlations more strongly attributable to shared environment than to genetic effects were found for Na,K-ATPase pump activity, intraerythrocytic magnesium, plasma digoxin-like factor, plasma renin activity, and plasma sodium concentration. All anthropometric variables tested showed highly significant genetic heritability with low and insignificant shared family environmental effects. Several of the genetically determined cellular cation tests also correlated with other genetic traits including plasma lipids, anthropometric measurements, and other cellular cation tests. Among hypertensive individuals with familial dyslipidemic hypertension, plasma insulin levels correlated with obesity and lipid abnormalities and with several cellular cation flux tests associated with hypertension.
Hypertension 1991 Jan
PMID:Genetic traits related to hypertension and electrolyte metabolism. 198 14

Hypertension in insulin resistance states is generally attributed to hyperinsulinemia, with resulting increases in renal sodium retention and/or sympathetic nervous system activity. However, recent data from our laboratory suggest that cellular insulin resistance, rather than hyperinsulinemia per se, may lead to hypertension. The basic tenet proposed in this review is that the common mechanism involved in the development of hypertension in both type I and type II diabetes mellitus is a deficiency of insulin at the cellular level. Recent observations suggest that impaired cellular response to insulin predisposes to increased vascular smooth muscle (VSM) tone (the hallmark of hypertension in the diabetic state). For example, recently reported studies from our laboratory demonstrate that insulin in physiological doses attenuates the vascular contractile response to phenylephrine, serotonin, and potassium chloride. Thus, insulin appears to normally modulate (attenuate) VSM contractile responses to vasoactive factors, and insulin resistance should accordingly be associated with enhanced vascular reactivity. Abnormal VSM cell calcium [Ca2+]i homeostasis may be the nexus between insulin resistance and increased VSM tone. The genetically obese, hyperinsulinemic, insulin-resistant Zucker rat demonstrates increased vascular reactivity, reduced membrane Ca2(+)-ATPase activity, increased cellular Ca2+ levels, and a marked impairment in vascular smooth muscle Ca2+ efflux compared to lean controls. Insulin stimulates membrane Ca-ATPase, blocks Ca2+ currents, and Ca2(+)-driven action potentials. Thus, an insulin-resistant state as exists in the Zucker rat may be associated with increased Ca2+ influx through voltage-dependent sarcolemmal Ca2+ channels and/or decreased production or activation of the VSM cell Ca-ATPase pump.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Mechanisms of hypertension in diabetes. 202 49

The pathophysiology of hypertension in the black population differs to some extent from that of the nonblack population. Although black hypertensives exhibit enhanced sodium retention, expanded plasma volume, lower plasma renin activity, and a greater increase in blood pressure in response to high levels of Na+ intake compared with nonblack hypertensives, there is considerable heterogeneity in these studies. Alterations in ion transport mechanisms, such as a decrease in Na+K(+)-ATPase activity and Na+K+ cotransport, have been demonstrated in the black hypertensive population. Those features provide the physiologic basis for the differential response to monotherapy with diuretics and, perhaps, with calcium channel blockers, that is observed in black hypertensives, particularly when compared with responses to beta-blockers or angiotensin converting enzyme inhibitors.
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PMID:Pathophysiology of hypertension in blacks. 207 24

The association between arterial hypertension and obesity has been known for many years and demonstrated by epidemiological studies. The physiopathological mechanisms involved consist of increased extracellular volumes, hyperactivity of the sympathetic nervous system and the renin-angiotensin-aldosterone system, and abnormal ion exchanges between extra- and intracellular compartments. Recent studies have demonstrated an association between arterial hypertension and insulin resistance. Insulin resistance may well be the most important aetiological factor in this type of arterial hypertension as it stimulates both renal sodium reabsorption and sympathetic nervous system activity and reduces vascular Na-K-ATPase activity.
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PMID:[Arterial hypertension in patients with obesity. Role of hyperinsulinism and insulin resistance]. 209 34

In the presence of NADPH cytochrome P-450-dependent monooxygenases oxidize arachidonic acid giving rise to four epoxyeicosatrienoic acids (EETs) which are hydrolyzed enzymatically to dihydroxyeicosatrienoic acids (DHETs). EETs generate vasodilators. Allylic oxidation forms hydroxyeicosatetraenoic acids, of which 12(R)HETE is an inhibitor of Na(+)-K(+)-ATPase and renin release. Finally, omega and omega-1 hydroxylation of arachidonic acid generates 20- and 19-HETEs which are involved in the development of hypertension in SHR rats.
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PMID:Cytochrome P-450 metabolites of arachidonic acid: implications for blood pressure regulation. 212 86

The cardiac changes resulting from mechanical overload of the left ventricle have been well documented and a variety of compensatory mechanisms described. These include a decrease in maximum velocity (V0) of shortening in the absence of reduction in active tension (P0), and a reversible decrease in myofibrillar adenosine triphosphatase activity resulting from isoenzymic shift from, predominantly, a form of myosin with high ATPase activity (V1) to another with low (V3). The thermodynamic advantage of the transition is the hypertrophied muscle possesses a more energy-efficient form of contraction. These reversible transitions resulted from altered gene expression of isoenzymic forms of myosin heavy chain. It must be borne in mind that the adaptational modifications just described appear to occur only in smaller animals such as the rat, that possesses several myosin isozymes. In large mammals it is mainly the V3 form of myosin that is present, which does not change with altered contractile state. Responses of the large arteries to hypertension have been poorly studied. This is surprising when one recalls that degenerative disease of such vessels, that include the aorta, carotids and ileo-femoral arteries is almost an obligatory concomitant of hypertension. Such studies as have been carried out indicate that hyperplasia is specific for abdominal aortic stenosis while hypertrophy is found in aortic smooth muscle in rats with systemic hypertension. Mechanically, an increase in V0 with no change in P0 have been reported; an increase in myofibrillar ATPase activity was also reported. Though two myosin heavy chain isozymes have been found in aortic smooth muscle densitometry did not reveal any difference in distribution between tissues from control and hypertensive rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cardiovascular adaptations to mechanical overload. 213 92

The causes of elevated intra-erythrocyte calcium in the offspring of essential hypertensive patients are unknown. Fourteen children with and without a family history of essential hypertension were chosen to compare erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity (Rbc-M Ca2(+)-Mg2(+)-ATPase activity) measured by biochemical methods. We found that Rbc-M Ca2(+)-Mg2(+)-ATPase activity was lower in children with family history of hypertension compared with children with no family history (2.16 +/- 1.10 vs 3.36 +/- 1.19 microM Pi/mg protein/hour P less than 0.01). These results suggest that the reduced Rbc-M Ca2(+)-Mg2(+)-ATPase activity may be one of the mechanisms causing the high erythrocyte calcium levels in the offspring of essential hypertensive patients.
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PMID:Comparison of erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity in children with and without family history of essential hypertension. 214 Jan 35

Calpain, a calcium-dependent, neutral cysteine-protease was purified from the erythrocyte cytosol of subjects having essential hypertension (HTN), sickle cell anaemia, (SCA), or kwashiorkor (KWA). Identical electrophoretic mobility on SDS-polyacrylamide gradient gel, sensitivity to micromolar amounts of Ca2+, absolute requirement for a reducing environment and a high susceptibility to inhibition by leupeptin and thiol-group modifying reagents confirm that calpain preparations from these erythrocytes are equivalent to calpain I. Whereas the extent of calpain activation of erythrocyte membrane Ca2(+)-pumping ATPase of normal subjects was almost equal to that due to calmodulin, calpain activation of the HTN and SCA pump was greater than activation by calmodulin. Like in normal membranes, exogenous calmodulin protected the Ca2(+)-pumping ATPase of these erythrocytes against calpainization; the degree of protection by calmodulin is least in SCA and HTN. Electrophoretic separation of erythrocyte membranes and the purified Ca2(+)-pumping ATPase of HTN, SCA and KWA subjects does not indicate the presence of fragments resulting from the proteolytic action of calpain.
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PMID:Comparative action of calpain on erythrocyte Ca2(+)-pumping ATPase in sickle cell anaemia, essential hypertension and kwashiorkor. 214 87

In this model hypertension developed as early as 1 wk. post-surgery and was associated with reduction in Ca2(+)-ATPase activity in cerebral vessels indicating that abnormalities in ionic calcium in vessel walls occur early in the evolution of hypertension. This study supports previous observations that cerebral cortical arterioles develop increased permeability to endogenous plasma proteins in chronic hypertension. The principal mechanism resulting in this increased permeability is enhanced pinocytosis. Ca2(+)-ATPase localisation in endothelial pinocytotic vesicles helped to localise transendothelial channels in occasional vessels of hypertensive rats. The latter findings reinforce the concept that in pathologic states associated with cerebral oedema, pinocytotic vesicles fuse to form transendothelial channels which transport plasma proteins into brain.
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PMID:Presence of transendothelial channels in cerebral endothelium in chronic hypertension. 215 Oct 11

Canrenone, a metabolic product of spironolactone, which competes with ouabain for binding to Na-K-ATPase at the digitalis receptor site and by itself inhibits Na-K-ATPase, was administered intramuscularly to reduced renal mass-saline drinking hypertensive and reduced renal mass-distilled water drinking normotensive rats for 8 days. Reduced renal mass-saline hypertension in the rat, is a low renin, volume expanded form of hypertension. Rats with this type of hypertension have been shown to have depressed arterial Na-K pump activity and increased Na-K pump inhibitory activity in their plasma. Canrenone treatment caused a progressive decrease in blood pressure in the hypertensive rats and this was associated with normalization of Na-K pump activity in arteries. Water and salt intake and excretion did not change. On the other hand, canrenone progressively increased blood pressure in the normotensive rats and this was associated with positive inotropy in isolated papillary muscles. These findings suggest that the depressed pump activity and the pump inhibitor play a role in reduced renal mass-saline hypertension in the rat and that the rise in blood pressure in the normotensive rats probably reflects canrenone's ability, by itself, to inhibit Na-K-ATPase.
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PMID:Effects of canrenone on blood pressure in rats with reduced renal mass. 215 66


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