摘要:

Antibodies raised to pure canine renal renin were used to probe homology of renin from other species. Goat, rabbit, and mouse antibodies exhibited similar properties and were specific for renin as confirmed by immunodiffusion, immunoelectrophoresis, and selective inhibition of renin enzymatic activity. Goat antibody also inhibited the enzymatic activities of rat, rabbit, hog, and bovine renin. Immunologic cross reactivity was further confirmed by direct binding and competition assays. Goat anti-(canine renin) antibody did not inhibit human or mouse renin activity, but readily bound to these enzymes, suggesting the presence of epitopes distant from the enzymatic site. Purified goat Fab retained only 10% to 20% of the anticatalytic activity of antibody, but this activity was largely recovered when donkey anti-goat antibody was added to the Fab-renin mixture. Thus, the major fraction (80% to 90%) of goat antibody exerted its anticatalytic activity by immune complex formation or steric hindrance and is not catalytic-site directed, whereas 10% to 20% binds an epitope at or near the catalytic site. (Hypertension 4: 341–347, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

An endogenous, immunoreactive digoxin-like factor (endoxin) was measured in the plasma of nonhuman primates with hypertension. Both normotensive and hypertensive rhesus monkeys had levels of endoxin that significantly correlated with their systolic or diastolic blood pressure. Vervet monkeys with experimentally produced chronic Goldblatt hypertension had significantly elevated endoxin, but not plasma renin. These data suggest that increased plasma endoxin may be a contributing factor in the development of hypertension. (Hypertension 4: 348–354, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Tests made of the sensory-perceptual, cognitive, and psychomotor abilities of untreated young patients with essential hypertension have revealed a pattern suggesting a slight functional impairment of the central nervous system. Reduced performance was most marked for those tasks requiring speed arid psychomotor coordination, particularly when the behaviors observed were self-initiated. Lowered scores were more evident among female hypertensives; no differences in performance by race were noted. The deficits measured by these sensitive tests do not appear to be great enough to intrude on everyday activity nor to impair work ability. Changes that may result from blood-pressure-lowering therapies will require further study. (Hypertension 4: 355–360, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The development of hypertension was studied in 3 to 13-week old New Zealand genetically hypertensive (NZGH) rats subjected to bilateral renal denervation (D) or sham operation (S) at 4 weeks of age. Denervation retarded the development of hypertension and delayed the establishment of stable hypertension; blood pressure of D-NZGH rats was 15–40 mm Hg lower than that of S-NZGH rats from 3 to 7 weeks after surgery, but was similar in the two groups thereafter. D-rat renal catecholaimine content was reduced to 17% of control at 1 week after surgery; by the fourth week post surgery, renal catecholamine content had risen to 40% of control, and blood pressure of the D-group had begun to rise, suggesting that spontaneous renal reinnervation prevented the antihypertensive effect of renal denervation from being a permanent one. During the period when blood pressure of the S-rats was greater than that of the D-rats, urinary sodium excretion of the two groups was not significantly different, suggesting that over this interval the relationship between blood pressure and urinary sodium excretion shifted to the right along the pressure axis in the S-rats but not in the renal-denervated rats. Throughout the 60-day period of observation, urinary excretion of prostaglandin E2and kallikrein did not differ between the renal-denervated and sham-operated rats. (Hypertension 4: 361–368, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Peripheral and central sympathetic mechanisms have been shown to contribute to the development and maintenance of increased blood pressure in the one-kidney model of renal hypertension in the rat. Previous studies from our laboratory have demonstrated that the renal sympathetic nerves, in particular, contribute to the maintenance of hypertension in this model. In those studies, renal denervation, performed 2 weeks after renal artery clipping, resulted in a significant decrement in blood pressure that was associated with a decrease in peripheral sympathetic activity. To further define the role of the renal nerves in the pathogenesis of hypertension in this model, we determined the systolic blood pressure and norepinephrine and dopamine content of the hypothalamus, midbrain, pons medulla, and spinal cord at 1 week following renal denervation or sham operation of rats with early established one-kidney one clip hypertension. Age-matched uninephrectomized rats were controls. The blood pressure of denervated animals decreased significantly from 189 ± 9.21 to 151 ± 6.5 mm Hg (p< 0.001), while that of sham-operated animals did not change. Hypothalamic norepinephrine content of sham-operated animals was significantly greater than that of controls (2.24 ± 0.8 μg/g sham vs 1.84 ± 0.12 μg/g controls,p< 0.01). Renal denervation resulted in a decrease in hypothalamic norepinephrine content to control levels (1.72 ± 0.11 μg/g)- There was a significant (r = 0.65,p< 0.01) positive correlation between systolic blood pressure and hypothalamic norepinephrine content of renaldenervated and sham-operated animals. The norepinephrine content of other brain regions was not different between groups. The results suggest that the renal nerves contribute to the maintenance of hypertension in the one-kidney one clip rat by modulating central sympathetic nervous system activity. (Hypertension 4: 369–373, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Induction of hypertension by implantation or injection of deoxycorticosterone acetate (DOCA) requires a dose well above the physiological range. The objective of this study was to produce hypertension in rats by chronic infusion of d-aldosterone, a more potent mineralocorticoid. Aldosterone infused at a dose of 1 μg/hr for 4 weeks gave a maximal rise in systolic blood pressure (132 ± 3 vs 203 ± 7 mm Hg). A significant rise in blood pressure was achieved at 0.1 μg/ht (170 ± 6 mm Hg) which was associated with a 2.3- fold rise in plasma aldosterone levels (7.6 ± 0.4 vs 17.7 ± 2.2 ng/dl). A series of isotope flux studies on the aorta and femoral artery from hypertensive animals demonstrated increases in “K and MC1 turnover. In both vessels the largest changes in ion turnover were observed in vessels from animals infused with aldosterone at 0.25 fig/hr. Increases in ”K and 9<G turnover were detected as early as 1 week after the start of aldosterone infusion, well before a significant rise in blood pressure had occurred. (Hypertension 4: 374–381, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

While total body mass has been recognized for many years as having a strong positive association with blood pressure, it is not known whether body mass per se is important in this association or if a component of total mass, such as lean body mass or total body fat, is responsible for the relationship. To determine the relative importance of these components, 217 healthy adults unselected with respect to blood pressure or body composition, who were 18 to 49 years of age (X ± SD = 33.1 ± 8.9 years) had body density measured by underwater weighing. Body density was used to estimate percent body fat from which lean body mass and total body fat mass were determined. In addition, an adipose tissue biopsy from the gluteal area was made, and average fat cell size was measured using the osmium tetroxide method; fat cell number was then estimated. In both males and females, after adjusting for age, there were highly significant, positive partial correlations (r = 0.2 to 0.3) between measures of blood pressure (systolic, diastolic, and mean arterial) and percent body fat, total body fat mass or fat cell number. No significant correlation existed between lean body mass or fat cell size and any. measure of blood pressure. These findings suggest that fat mass as opposed to body mass, per se, may be an important etiological component in elevated blood pressure in adults. (Hypertension 4: 382–386, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Lesions of the anteroventral third ventricle (AV3V), an angiotensin and osmosensitive region of the anterior hypothalamus, prevent or abort hypertension in a number of rat models. To determine if A V3V lesions alter hypertension in spontaneously hypertensive rats (SHR), lesions and control sham lesions were made in young SHR at 28 days of age. AV3V lesions had no effect on the development of hypertension in SHR. However, lesioned rats demonstrated significantly reduced pressor responses to intracerebroventricular injections of angiotensin II (AH) and hypertonic NaCl, and drinking produced by centrally administered AH. The depressor effect of central AH receptor blockade was also significantly attenuated in lesioned SHR. These effects appeared to be of central origin since the lesion did not affect the pressor action of intravenous AH or norepinephrine (NE). It is concluded that unlike other models of experimental hypertension (steroid-salt, oneand two-kidney renal, neurogenic) the development of hypertension in SHR does not depend upon the integrity of the AV3V region. (Hypertension 4: 387–393, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Several laboratories have reported evidence suggesting that in hypertension there are abnormalities in the activity of the sarcolemmal sodium pump in vascular smooth muscle. In the present study, by sampling tissue from both hypertensive and normotensive portions of the arterial tree in coarctation hypertension, we investigated the relationship of such abnormalities to the elevated intravascular pressure. Additionally, we measured plasma renin activity and body fluid volumes. We assessed sodium pump activity in vitro sodium-loaded arteries freshly excised from rats with chronic coarctation hypertension (abdominal aorta constricted above the renal arteries 4 to 5 weeks previously) and from normotensive sham-coarcted rats; these included the tail artery, the hypertensive thoracic aorta, and the normotensive portion of the abdominal aorta below the clip. The Rb uptake in the absence (total uptake) and presence (ouabain-insensitive uptake) of 1.0 mM ouabain was measured, and ouabain-sensitive uptake (nmole/mg dry weight/10 min) was calculated. In the rats with coarctation hypertension, there were significant increases in the ouabain-sensitive and total Rb uptakes in both the thoracic and abdominal aorta, but no abnormalities in Rb uptake in the tail artery. The higher uptakes in tissue from coarcted rats could not be attributed to increased levels of intracellular sodium. Plasma renin activity was elevated in the coarcted rats, but no changes in body fluid volumes were detected. This study provides evidence that increases in the activity of the sodium pump, similar to those we have observed in tissue from rats with salt-induced or Goldblatt hypertension, occur in conduit arteries of rats with coarctation hypertension studied in vitro. Because similar increases occur in vascular smooth muscle of the normotensive and hypertensive portions of the aorta, these pump abnormalities in arteries do not appear to be the direct result of increased intravascular pressure and probably are not attributable to tissue hyperplasia. Hypertension 4: 394–399, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

To evaluate the partial contributions and interaction of three vasopressor systems in blood pressure maintenance, nephrectomized rats and rats with intact kidneys were submitted sequentially to catecholamine depletion, elimination of vasopressin's vasoconstrictor action, and (for those with kidneys in situ) angiotensin blockade. Catecholamine depletion decreased blood pressure and stimulated vasopressin levels in all rats, but significantly more so in the anephric ones. Subsequent injection of an antagonist to the vasopressor effect of vasopressin produced a lasting fall of blood pressure in anephric rats, but only transient fall in those with intact kidneys. Infusion of teprotide — an angiotensin converting enzyme inhibitor — in the latter animals also produced transient blood pressure fall, but if this were followed by injection of the vasopressin antagonist, the pressure remained low for several hours. Blood pressure levels were closely correlated with those of plasma catecholamines throughout these maneuvers. Catecholamine levels were inversely correlated with those of plasma vasopressin, which were far greater in anephric rats through both stimulation and accumulation. Plasma renin activity was increasingly stimulated by falling blood pressure after each maneuver in rats with intact kidneys. Thus, it appears that in the resting state the sympathetic nervous system is more involved in the maintenance of blood pressure, whereas vasopressin and renin are important backup mechanisms. (Hypertension 4: 400–405, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID