摘要:

Aortic vascular smooth muscle from spontaneously hypertensive rats (SHR) is known to respond in vitro to nonphysiologic cations with greater contraction than vascular smooth muscle from certain normotensive control stocks. The pattern of inheritance of the response of aortic rings to cobalt (Co2+) in vitro was determined. The test characteristic utilized was the cobalt response ratio (CRR) defined as the contractile response to 0.6 μM Co2+divided by the response given by maximal stimulation with 10 μM Co2+. The SHR were crossed with Dahl salt-resistant rats that had been inbred for 21 generations (R/JR strain) to produce F1, F2, and backcross populations. The CRR was 0.90 ± 0.011 in SHR, 0.74 ± 0.016 in F1, and 0.38 ± 0.031 in R/JR. The F1value was significantly higher than the midparental value indicating partial SHR dominance. The F1males from reciprocal crosses had similar CRR indicating no sex-linked effect. In the backcross to the R/JR, the CRR showed a bimodal distribution segregating one intermediate type: one R/JR type. In the backcross to the SHR the CRR showed a unimodal distribution. In F2rats there was a bimodal distribution segregating three intermediate type: one R/JR type. In F2rats there was a significant (p< 0.005) blood pressure difference of 9.7 mm Hg between phenotypes. It is concluded that there is an autosomal locus (named “Hyp-2” for hypertension locus number 2) controlling vascular smooth muscle response to Co2+, which exhibits partially dominant inheritance. Alleles at Hyp-2 segregate with an increment in blood pressure. (Hypertension 4:459–467, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

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ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

$$

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Many studies have explored the relationship between blood pressure and body size and composition in adults and preadults, but none has inquired into the relationship of blood pressure and the anatomical distribution of subcutaneous fat (fat patterning). Fat patterning has an association with chronic diseases (diabetes and cardiovascular disease) in adults. We sought the relationship between fatness, fat patterning, weight, and height among adolescents (12 to 17 years of age) of two ethnic groups (black and white) from the Health Examination Survey. Systolic blood pressure adjust-ed for age was related to body build variables in all sex/ethnic groups in decreasing order of impor-tance as follows: body weight (independent of height), fatness (as assessed by a two skinfold index), and an excess of fat on trunk relative to fat on the leg (pattern index). Neither fatness nor fat patterning was significantly related to blood pressure after weight entered the regression equation. Relative fat patterning may be less important in pedicting cardiovascular risk factors in adolescents than it is in adults. The fact that body weight was more important than fatness suggests that the weight/blood pressure association is due to components of body mass other than body fat. (Hypertension 4:483–486, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Relationships among systolic blood pressure (SBP), plasma renin activity (PRA), arterial renin concentrations (ARC), and venous renin concentrations (VRC) were examined in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats before and after treatment with captopril. The ARC was elevated in SHR relative to WKY whereas VRC was not. Similarly, ARC was related to SBP (r= 0.69,p< 0.01) whereas PRA was not (r= 0.04). Captopril (100 mg/kg daily by mouth for 8 days) decreased blood pressure significantly in both SHR and WKY. PRA as well as ARC and VRC were all increased by captopril. Bilateral nephrectomy virtually eliminated PRA but ARC was not significantly reduced over a 24-hour period. Bilateral nephrectomy also markedly attenuated the acute antihypertensive effects of captopril in SHR; however, a modest effect was still apparent. It is suggested that ARC in SHR, being higher than in WKY, may play a role in the genesis or maintenance of hypertension in this model. Furthermore, the effects of captopril in both intact and nephrectomized SHR may be related to the ability of captopril to inhibit the vascular formation of angiotensin II. Finally, vascular renin is probably not renal in origin and responds to typical feedback inhibition as unmasked by captopril administration. (Hypertension 4:487–493, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

This study was undertaken to formulate reliable confidence limits for the relationship between nocturnal and 24-hour urine sodium (Na) excretion for use in population compliance studies. Urine excretions were measured in 12 white and 12 black men at three levels of sodium (Na) intake (10, 200, and 400/) for 7 days. Nocturnal Na, chloride (Cl), and Cl determined by titrator stick were all highly correlated (r⩾0.86,p< 0.001) with 24-hour UNaV. No significant difference could be attributed to race. Discriminate analysis revealed that the subjects could be categorized with respect to Na intake with accuracies of 95°, 90°, and 85° (low, middle, and high Na intake respectively) by means of two nocturnal urine Cl titrator stick measurements. In addition, two such measurements showing nocturnal UclV < 10 mEq indicated with 95° accuracy that 24-hour UNaV was < 60 mEq. According to these data, measurement of nocturnal Na or Cl excretion is a useful means of assessing compliance to a low sodium intake, and the titrator sticks are a convenient and inexpensive tool. (Hypertension 4:494–498, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Alpha methyldopa has been shown to modify left ventricular mass and normalize/volume ratio in spontaneously hypertensive rats (SHR) when administered during the stage of developing cardiac hypertrophy (Tomanek et al., Cardiovas Res 23:173, 1979). To evaluate the long-term effects of this antihypertensive agent, the drug was administered to SHR and normotensive (WKY) rats between the ages of 1 and 12 months. In another group of SHR and WKY, treatment was delayed until the age of 12 months and the animals were then treated for 3 months. Treatment with α-methyldopa had similar effects on systolic blood pressures in both SHR groups; group means ( ± SF.M) were 151 ± 1 in the long-term treatment group and 157 ± 5 in the delayed treatment group compared to 178 ± 4 and 176 ± 3 for their respective controls. While left ventricular weight and cell size were significantly lower after early long-term treatment (compared to nontreated SHR), delayed treatment had no significant effect on these indices of left ventricular mass. Despite the effectiveness of early long-term treatment in modifying left ventricular mass, the relative volumes of mitochondria and myofibrils, as well as other cellular components (sarcoplasm), were not altered. In contrast, delayed treatment caused a significant increase (approximately twofold) in relative sarcoplasmic volume and a decrease in relative myofibrillar volume in both SHR and WKY. These findings indicate that shifts in the relative volumes of intracellular components after α-methyldopa are independent of cell size and blood pressure. Furthermore, the data suggest that the effects of α-methyldopa on the myocardial cell are dependent on or influenced by factors associated with the development or stabilization of hypertrophy/age. (Hypertension 4:499–506, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), plasma norepinephrine (NE), and epinephrine (E) levels at rest and in response to orthostatic stress of quiet standing were compared in 19 subjects with borderline hypertension (BH) (SBP-135 mm Hg, DBP-80 mm Hg), nine with significant hypertension (SH) (SBP-150 mm Hg, DBP-95 mm Hg), 14 normotensive siblings (NS) of hypertensives (SBP-113 mm Hg, DBP-64 mm Hg), and 21 age-matched normotensive controls (NC) (SBP-116 mm Hg, DBP-61 mm Hg). Group resting plasma NE levels were significantly higher in BH (454/,p< 0.001/) and SH (384/,p< 0.01/) than in NC (281/) or NS (309/), and more than 2 SD above the NC mean value in 50° of BH, 28° of SH, and 7° of NS. Plasma E levels were similar. On standing, mean arterial pressure (MAP) rose 13.7 mm Hg in NC, 3.9 mm Hg in BH, and 2.8 mm Hg in NS, and fell 7.3 mm Hg in SH. These differences reflect the frequent occurrence of hypotensive responses in study group subjects, which were not observed in NC. The mean rise in plasma NE with standing was blunted in hypertensives, increasing 40° to 50° compared with 95° in NC. In BH and NS, SBP was positively correlated with plasma NE levels at rest and with standing. These observations offer support for the hypothesis that altered adrenergic sympathetic nervous system (SNS) activity is present in a subgroup of young hypertensives and can be a contributing factor to their hypertension. Findings of similar SNS activity in some normotensive siblings suggest that genetic factors might be involved. (Hypertension 4:507–513, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Evidence for the brain renin-angiotensin system being involved in the hypertension of the spontaneously hypertensive rat (SHR) includes central administration of angiotensin II (All) antagonists and converting enzyme inhibitors that lower blood pressure in SHR. Using the unlabeled antibody enzyme method, we have found a significant difference in the distribution of brain angiotensin in SHR and Wistar-Kyoto controls (WKY). Six rats of each group were perfused with buffered picric acid-paraformaldehyde, and their brains sectioned at 50 and 100 μ. The sections were reacted with a IMOOO dilution of AH antisenim for 36 hours followed by goat antirabbit immunoglobulin G and rabbit peroxidase antiperoxidase. For controls, preabsorption with All, arginine vasopressin or preimmune serum were evaluated. The results showed over twice as many cells and fibers staining for All-like immunoreactivity in SHR. The AH immunoreactive cell bodies were localized, in the order of their relative preponderance, in supraoptic and paraventricular nuclei of the hypothalamus, hippocampus, and cortex. The most prominent demonstration of All-like immunoreactivity was observed in fiber profiles containing densely stained varicosities, which were present in many neuroanatomical subdivisions of the brain and brain stem including anterior and middle hypothalamus, basal ganglia, thalamus, locus coeruleus, nucleus of the solitary tract, limbic structures, and reticular formation. The increased fiber staining in the SHR was particularly evident in the frontal hypothalamic region, medial preoptic, and stria terminalis. We conclude that the results support the hypothesis of brain AH involvement in hypertension. (Hypertension 4:514–523, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

To assess the relative importance of the level of blood pressure (BP) and renin profile status as determinants of hypertensive left ventricular hypertrophy (LVH) and dysfunction, we studied, by quantitative echocardiography, 118 hypertensive patients off medication. The 19 highrenin patients were younger (31 ± 13 years;p< 0.01) but had hypertension of severity (152 ± 13/95 ± 11 mg Hg) similar to the 79 normal-renin patients (42 ± 14 years; 152 ± 17/98 ± 12 mg Hg) and 20 low-renin patients (49 ± 13 yrs; 157 ± 17/95 ± 1 1 mm Hg). Left ventricular (LV) mass index (normal = 70 ± 25/2) was similar in the high- (113 ± 21/2,p< 0.001), normal = (114 ± 31/, p < 0.001), and low-renin patients (115 ± 18/2,p< 0.01). End-diastollc relative wall thickness (nl = 0.32 ± 0.05) was equally elevated in high- (0.41 ± 0.09), normal (0.42 ± 0.08) and low-renin groups (0.41 ± 0.08) (allp< 0.001). In the entire population, there was a closer correlation of relative wall thickness with total peripheral resistance (r= 0.54,p< 0.001) than with mean blood pressure (r= 0.31,p< 0.05). LV dysfunction (LV fractional systolic shortening < 26°) occurred only in two high-renin patients, whereas LV fractional shortening was significantly increased in the low-renin subgroup (p< 0.01). We conclude that the degree of LVH is similar in low-, normal-, and high-renin hypertensives and is proportional to the degree of hypertension, even though the high-renin patients were significantly younger; but that the lowrenin patients with similar level of blood pressure, even though significantly older and with a longer duration of hypertension than the other patient groups, manifest increased LV function compared to normals. (Hypertension 4:524–531, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID