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

A new concept is established in the etiopathogenic mechanism of renovascular hypertension. After performing two stenoses of the renal artery, according to Goldblatt's method, with an interval of 5 months between each, it is noted that the variations in the figures for arterial blood pressure depends directly on the reduction of renal mass. This is backed up by reninemia and pathological anatomy. With this, the concepts of static or dynamic stenosis of the renal artery are pinpointed.
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PMID:The renal blood flow/renal mass relation in renovascular hypertension. 63 Nov 59

Rats with classic Goldblatt (two-kidney) hypertension had diabetes induced by streptozotocin. After four months of diabetes, glomeruli of the unclipped kidney of hypertensive diabetic rats had markedly increased diabetic changes, including mesangial matrix thickening and mesangial immunoglobulin (IgG and IgM) and complement (C3) localization, when compared with glomeruli of the contralateral-clipped kidneys. Further, glomeruli of the unclipped kidneys of hypertensive diabetic animals had more mesangial thickening and IgG and IgM staining than glomeruli of normotensive diabetic rats. Although glomeruli of clipped kidneys in hypertensive diabetic rats had less mesangial thickening than glomeruli of normotensive diabetic rats, this did not reach statistical significance. However, these glomeruli did have significantly less IgG, IgM, and C3 staining compared with glomeruli of normotensive diabetic animals. Mesangial thickness in glomeruli of clipped and unclipped nondiabetic hypertensive rats did not differ from that in normal animals. However, there was less mesangial IgG staining in clipped than in unclipped kidneys of nondiabetic hypertensive rats or in kidneys of normal animals. We have interpreted these results to imply that alterations in nephron hemodynamics combine with the diabetic state to influence the rate of development of diabetic glomerulopathy in rats.
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PMID:The effects of Goldblatt hypertension on development of the glomerular lesions of diabetes mellitus in the rat. 65 20

We isolated and perfused both the "clipped" and "contralateral" kidneys from Goldblatt renal hypertensive and sham-operated control rats, 1--104 days postoperatively. Responses to renal nerve stimulation were depressed in clipped kidneys from hypertensive rats (1 day postoperative), and these kidneys were supersensitive to exogenous norepinephrine (1--31 day) when compared with the contralateral organ of the same animal. Similar alterations were found between clipped and contralateral kidneys from sham-operated control rats. There was no difference in responses to renal nerve stimulation of norepinephrine between clipped kidneys from hypertensive and control rats, but clipped kidneys from hypertensive rats were supersensitive to angiotensin II (17 and 31 days). Comparison of contralateral kidneys from hypertensive and control rats revealed no change in norepinephrine sensitivity or in responses to renal nerve stimulation, but there was a reduction in the slope of the dose-response curve to norepinephrine and of the maximal effect of the catecholamine (104 days) and a pronounced supersensitivity to angiotensin II (17--104 days) in the hypertensive rats. These results indicate that (1) renal nerve function and norepinephrine sensitivity of the isolated renal vasculature are unchanged in renal hypertension, but clipping partially denervates the kidney causing depressed nerve function and unilateral norepinephrine supersensitivity, unrelated to hypertension; (2) the prolonged high pressure load on the contralateral kidney may impair the function of the vascular smooth muscle; and (3) bilateral supersensitivity to angiotensin II is associated with hypertension but is not solely a consequence of the high pressure.
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PMID:Increased renal vascular reactivity to angiotensin II but not to nerve stimulation or exogenous norepinephrine in renal hypertensive rats. 68 57

The purpose of the study was to examine the value of regular measurements of plasma renin concentration (PRC) in selecting those chronic haemodialysis patients suitable for bilateral nephrectomy to prevent development of uncontrollable hypertension. Regular measurements of arterial blood pressure (BP) and PRC were performed during one year in 31 patients undergoing regular haemodialysis because of end-stage renal disease. Among 18 patients with PRC greater than or equal to 100 micro Goldblatt units per ml plasma (microGU/ml) systolic and/or diastolic hypertension persisted or developed in 12. In contrast, among 13 patients with PRC greater than 100microGU/ml, BP became normal in all but one, who had a slightly increased systolic BP. However, hypertension was mild and easily controlled by conventional therapy in all except one, who probably had an overlying volume-dependent hypertension. Therefore, bilateral nephrectomy was not necessary in any case. The results indicate that hypertension in the majority of chronic haemodialysis patients with high PRC can be adequately controlled without surgical intervention and that regular measurements of PRC have no practical value in forecasting the development of uncontrollable hypertension in chronic haemodialysis patients.
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PMID:A longitudinal study of arterial blood pressure in chronic haemodialysis patients with different levels of plasma renin concentration. 69 42

In order to clarify the molecular basis of the unique features of rat renin (EC 3.4.99.19) and to provide materials and basic information for high blood pressure studies in rats, renin was purified from rat kidney. The final step of purification on CM-cellulose separated renin into three major isoenzyme peaks, R-I, R-II, R-III, and an additional minor peak. These preparations were judged homogeneous by multiple criteria, and the isoenzymes were found to have similar amino acid compositions. The amino acid composition is also closely analogous to hog renin, except that rat renin has a higher cysteine content. In contrast to hog renin, the rat enzymes do not contain amino sugars, yet are apparently glycoproteins as judged by their affinity for concanavalin A. The molecular weights of R-I, R-II, and R-III were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 37 000, 36 000 and 35 000, respectively. The isoelectric points were 5.05, 5.15 and 5.22, respectively. The specific activities of the purified enzymes (determined using rat plasma as substrate) were 615, 626 and 452 Goldblatt units/mg, respectively. Comparison of activities with the hog- and rat-derived substrates indicated a preference for that from the rat. The reaction of the rat enzymes with a synthetic peptide substrate had a similar catalytic rate constant to the hog enzyme, indicating close similarity in the active site region of the two enzymes.
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PMID:Rat renin: purification and characterization. 71 49

1. Hypertension produced in two-kidney Goldblatt dogs was accompanied by a transient fluid retention, reaching a maximum 4 days after clamping. 2. Prostaglandin E and F concentrations in venous blood from the intact kidney also rose transiently, showing a maximum by the fifth day. 3. The rise in prostaglandin release from the intact kidney may be related to the fluid retention.
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PMID:Renal prostaglandins in renal hypertensive dogs. 75 Jan 58

The development of hypertension was studied in rats after neonatal sympathectomy by s.c. injection of 6-hydroxydopamine HCl. Three different types of hypertension were investigated: renal hypertension in the two-kidney Goldblatt model, steroid hypertension produced by deoxycorticosterone (DOCA) implantation and saline as drinking fluid, and genetic hypertension in the spontaneous hypertensive rat (SHR). Blood pressure was measured directly in conscious animals via the iliac artery. Mean blood pressure of conscious sympathectomized (SX) normotensive rats was not significantly different from that of normotensive controls. Renal hypertension reached the same level in controls and SX rats four weeks after application of a renal artery clip. DOCA-salt hypertension developed faster and to a higher level in SX rats than in control rats. The hypertension in SX DOCA-salt hypertensive rats was accompanied by a marked tachycardia. In contrast hypertension did not develop in SX SHR. Up to 12 months of age mean blood pressure was markedly lower than that of control SHR, but slightly higher than that of SX normotensive Wistar Kyoto rats. These differential effects of neonatal sympathectomy on the development of hypertension in the rat may point to differences in the pathophysiological mechanisms. It is concluded that an intact sympathetic nervous system is essential for the development of hypertension in SHR. In DOCA-salt hypertension the intact sympathetic nervous system appears to protect against a rapid rise in blood pressure.
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PMID:Differential development of renal, DOCA-salt, and spontaneous hypertension in the rat after neonatal sympathectomy. 75 48

Ablation of tissue surrounding anteroventral third ventricle (AV3V) was studied in three models of hypertensive rats. Lesions were placed in the AV3V at one and six weeks following the initiation of one kidney Grollman renal hypertension. At one week the rise in blood pressure was arrested and water intake was reduced; at six weeks arterial pressure returned to prehypertensive levels in animals surviving the post-lesion hydrational crisis. In two kidney (one clip) Goldblatt animals lesioned two weeks post-clip, arterial pressure was significantly reduced but did not become fully normotensive. Finally, the AV3V was also lesioned in spontaneously hypertensive rats (SHR-Okamoto strain) with established hypertension. The lesion did not reduce arterial pressure in adult SHR although characteristic initial adipsia and weight loss occurred. Ablation of the AV3V thus altered the course of maintenance of renal hypertension; however, the arterial pressure of SHR was not affected.
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PMID:Interruption of the maintenance phase of established hypertension by ablation of the anteroventral third ventricle (AV3V) in rats. 75 72

1. Plasma noradrenaline concentrations and dopamine beta-hydroxylase activity have been measured at various stages in the development of hypertension in the one-kidney Goldblatt rat (unilateral renal arterial constriction and contralateral nephrectomy). 2. Although plasma noradrenaline concentrations were significantly elevated from control values at 7, 14 and 28 days, plasma dopamine beta-hydroxylase activity was not significantly different from control values except at 24 h. 3. These findings suggest that peripheral sympathetic activity is increased in the one-kidney Goldblatt model of experimental hypertension but that plasma dopamine beta-hydroxylase activity is poor index of this increase. 4. Both the rise in blood pressure and the rise in plasma noradrenaline concentrations were prevented by pretreatment with intracisternal 6-hydroxydopamine, suggesting that the increased sympathetic activity is at least in part centrally mediated.
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PMID:Plasma noradrenaline concentrations in experimental renovascular hypertension in the rat. 86 41

1 Plasma noradrenaline concentrations were similar in rats following unilateral renal arterial constriction (two kidney Goldblatt model) and in sham-operated control rats. 2 The development of hypertension was not affected by pretreatment with intracisternal injections of 6-hydroxydopamine. 3 These data suggest that sympathetic mechanisms do not contribute to the development of hypertension in this model.
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PMID:Central and peripheral noradrenaline in the two kidney model of renovascular hypertension in the rat. 92 50


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