Comparison of erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity in children with and without family history of essential hypertension

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.

Effect of treatment with nimodipine in patients with mild and moderate essential hypertension

This study shows that nimodipine significantly reduces levels of blood pressure in patients with mild and moderate essential hypertension. Hypotensive efficacy is less than with nifedipine, but side effects are light, and the drug is shown to reduce serum Na+ and cholesterol and there is regression of LVH (ECG).

Aortoarteritis: a report of 480 cases

We report 480 patients with aorto-arteritis studied in our group. Among 320 patients, who were diagnosed by aortography the female to male ratio was 2.8:1, and the age of onset ranged from 5-45 years. The patients were followed for 1-27 years (average 6.8 years). Two hundred and eighty-six (59.6%) patients with renovascular hypertension were found in the group. All patients were treated with medical or surgical procedures. One hundred and thirty patients with renovascular hypertension were operated upon by revascularisation or uninephrectomy and 11 patients with renal artery stenosis were subjected to percutaneous transluminal renal angioplasty. There were 55 deaths (11.5%) in the group, cerebral haemorrhage being the major cause of death. Five year and ten year survival rates were 93.1% and 91.1% respectively.

Renovascular hypertension in China--report of 200 cases

Renal arteritis and fibromuscular dysplasia are two common causes of renovascular hypertension in China. The diagnostic approach now is arteriography or digital subtraction arteriography first, followed by renal vein renin assays to evaluate the functional significance. Surgical treatment is preferred if clinical status of the patients permits.

The value of the captopril test and the effect of captopril on renal function

We have investigated the use of captopril as a screening test for renovascular hypertension and compared the effects of captopril on renal function in patients with renovascular hypertension and those without renovascular hypertension. The captopril test and kidney gamma scintigraphy were carried out in 50 hypertensive patients, 13 with renovascular hypertension and 37 without. Blood samples were drawn for the determination of plasma renin activity and kidney gamma scintigraphy was done before and 60 minutes after 50 mg oral captopril administration. Results suggesting the diagnosis of renovascular hypertension are the following: a basal and stimulated plasma renin activity of 4 ng ml/hr or more and an absolute increase in plasma renin activity of 3 ng/ml/hr or more if basal plasma renin activity was less than 4 ng/ml/hr. Data from kidney gamma scintigraphy showed that captopril causes a decrease in clearance rate at 20 minutes in patients with renovascular hypertension but not in patients without renovascular hypertension. We conclude that the captopril test can be used to screen for renovascular hypertension, but catopril may impair the renovascular hypertensive patient's renal function.

Atrial natriuretic peptide lowers pulmonary arterial pressure in patients with high altitude disease

The authors' previous studies have demonstrated that IV administration of atrial natriuretic peptide (ANP) produces a dose dependent decrease in pulmonary arterial pressure in rats adapted to chronic hypoxia. To examine the effects of ANP on chronic hypoxic pulmonary hypertension in man, alpha-human ANP (200 micrograms) was infused (20 micrograms/min X 10 min) into the right atrium via a Swan-Ganz catheter in four patients with pulmonary hypertension of high altitude. Following the infusion, pulmonary arterial pressure fell gradually and remained depressed for 1 hour. Peak reductions in pulmonary arterial systolic pressure (PASP) and mean pulmonary arterial pressure (MPAP) were 23% and 30%, respectively. Systemic arterial pressure, cardiac output and cardiac index also tended to decrease, but these changes did not reach statistical significance. The data suggest that ANP is useful in the treatment of chronic hypoxic pulmonary hypertension in man.

Calcitonin gene-related peptide in the pathogenesis and treatment of hypertension

The present study demonstrated that the plasma calcitonin gene-related peptide (CGRP) concentration was lower but the CGRP content of abdominal aorta was higher in spontaneously hypertensive rats (SHR) than in normotensive rats (WKY), using specific CGRP radioimmunoassay (P less than 0.01). In eighteen patients with essential hypertension, the concentration of plasma CGRP was also much lower than that of normal subjects, suggesting that a decreased release of arterial CGRP might be a part of the pathogenesis of essential hypertension. In SHR, a significant decrease in blood pressure was found following intravenous injection of 2.5 micrograms/kg of CGRP; similarly, in seven patients with essential hypertension intravenous injection of CGRP (50 micrograms) could induce a significant hypotensive effect. These data suggest that CGRP is a new potential drug for the treatment of essential hypertension.

[Comparison of erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity in children with and without a family history of essential hypertension]

15 children with and without family history of essential hypertension respectively were chosen to compare erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity measured with biochemical method. Results were as follows: erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity was lower in children with family history of essential hypertension (2.16 +/- 1.10 vs 3.36 +/- 1.19 mumol Pi.mg protein-1/hour, P less than 0.01). This may be the cause of increase of intraerythrocyte calcium in offspring of hypertensive patients.

[Effects of complex of 3,6-di-(dimethylamino)-dibenzopyriodonium with praseodymium dicitrate on the syntheses of DNA, RNA, protein, nucleoprotein and ATP of leukemia L 7712 cells in mice]

The incorporations of [3H] thymidine, [3H]uridine and [3H]leucine into DNA, RNA and protein synthesis in leukemia 7712 cells were inhibited by the complex of 3,6-di-(dimethylamino)-dibenzopyriodonium with praseodymium (Pr, rare earth element) dicitrite 34 micrograms/ml for 3-24 h. The degree of inhibition increased in proportion to the incubation time. After being treated with [C17H20N2I]3[Pr(C6H5O7)2] 34 micrograms/ml for 3, 6, 12 and 24 h, the incorporation of [32P]Na2HPO4 into the nucleoprotein of leukemia 7712 cells was inhibited by 49, 57, 65 and 85%, while those into ATP were inhibited by 43, 59, 65 and 83%, respectively. The ID50 of [C17H20N2I]3[Pr(C6H5O7)2] on DNA synthesis in leukemia 7712 cells at 24 h was 22 micrograms/ml. After the complex was removed from the medium entirely, the rate of DNA synthesis decreased with time over 3-12 h. This result indicated that the inhibition mechanism was likely due to damage to the DNA template.

Calcium antagonists in prevention of hypertension and stroke in stroke-prone spontaneously hypertensive rats

To investigate the effect of Calcium antagonists (Ca-An) with different tissue specificity in the development of hypertension and stroke in salt-loading SHRSP, three experiments were conducted. In experiment I (1), 50 8-week-old male SHRSP were divided into three groups and given nifedipine (NF, 32 mg/kg/day), menidipine (MN 32 mg/kg/day) and placebo (control group) respectively. In the control group 83.3% (15/18) died of stroke and 17 showed renal vascular sclerosis. Their average lifespan was 84 days. NF and MN significantly reduced systolic blood pressure (SBP), and no stroke of renal vascular sclerosis developed. In experiment I (2), 54 7-week-old male SHRSP were divided into three groups (18 in each group). They were treated with nimodipine (NM) 20 mg/kg/day, 2 mg/kg/day and placebo respectively. NM (20 mg/kg/day) markedly lowered SBP and postponed the onset of stroke. Only 11% died in 17 weeks. NM (2 mg/kg/day did not lower SBP but postpond the onset of stroke. In experiment II (1), 29 10-week-old female SHRSP were divided into three groups: Group A was given NF 32 mg/kg/day, group B was parathyroidectomized (PTX) and group C served as control. PTX group did not lower SBP but could postpone the onset of stroke. In experiment II (2), 33 male SHRSP were divided into three groups and ticated as described above in experiment II (1) (11 in each group). Seven weeks after the experiment, the brain blood flow of NF group was significantly greater (67.5%) than that of the control and PTX groups. In experiment III, 27 7-week-old male SHRSP were divided into three groups as described above in experiment I (2).(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary cations and blood pressure: a collaborative study of 16 districts in China

Relationships between blood pressure and overnight urinary sodium, potassium and calcium were investigated in 3248 subjects from 16 districts in China. Average systolic (SBP) and diastolic (DBP) blood pressures of subjects from northern, middle and southern China were 116/74.2, 114/70.5 and 110.8/69.6 mmHg, respectively. Urinary sodium, potassium and calcium were 55.1, 8.3 and 1.1 mmol/l for the north, 63.6, 9.2 and 1.6 mmol/l for the middle and 50.0, 8.9 and 1.5 mmol/l for the south, respectively. The urinary sodium to potassium ratio was significantly and positively correlated with SBP and DBP in both males and females. Urinary sodium was weakly and positively correlated with SBP only in the north. Females over the age of 50 years were especially sensitive to sodium intake. Urinary calcium was negatively correlated with DBP in both males and females. Urinary calcium (creatinine) was negatively correlated with SBP in males, and with SBP and DBP in the south. Urinary potassium was negatively correlated with SBP and DBP only in the 20-29 year age group. Urinary potassium (creatinine) was negatively correlated with DBP only in the south. Age and body mass index were positively and level of education negatively correlated with blood pressure. Dietary factors for higher blood pressure in northern China were related to higher sodium, lower potassium and possibly lower calcium intake.

Monitoring effects of alpha-human atrial natriuretic polypeptide (alpha-hANP) on left ventricular function in patients with essential hypertension with a cardiac probe

The effects of alpha-hANP on left ventricular function were studied with a cardiac probe in ten patients with essential hypertension. Our data showed that intravenous administration of alpha-hANP significantly elevated left ventricular function. At 5 min, the elevation of EF, RCO, ER, RSV, PFR were 13.23% (P less than 0.02), 12.7 (P less than 0.02), 0.618 (P less than 0.02), 0.133 (P less than 0.05), 0.283 (P less than 0.01), respectively. At 10 min, the increase of EF, ER, were 11.07% (P less than 0.02) and 0.233 (P less than 0.01), respectively. Atriopeptin significantly reduced systolic and diastolic blood pressure from 2 min to 20 min (P less than 0.001-0.05).

Variability of urinary sodium and potassium excretion in north Chinese men

Variability of urine sodium (Na), potassium (K) and sodium/potassium (Na/K) excretion was studied in a sample of 50 employed normotensive male health professionals aged 27-50 in Beijing, China. Six 24-h urine specimens were collected from each participant during night-time (12-h) and daytime (12-h) fractions. The estimated ratio of intra- to inter-individual variances was 2.12 for night-time and 1.48 for 24-h urine Na, and 1.85 and 1.54, respectively, for urine K. Based on these values, six night-time and four 24-h urine specimens are necessary to reduce to 15% the diminution of a correlation between urine Na and another physiological variable. The corresponding numbers are five and four, respectively, for urinary K measurement. These data suggest that the ratio of within-person variation to between-person variation in Na excretion is smaller in these Chinese men than in Americans. The dietary Na intake of Chinese men can therefore be characterized with fewer urine specimens than are required for western populations. Night-time urinary Na and K showed good concordance with those from 24-h specimens in distinguishing high or low Na and K intake. These findings indicate that in large-scale epidemiological studies, overnight specimens may be adequate for classifying individuals with regard to Na and K intake.

Therapeutic actions of alpha-human atrial natriuretic polypeptide in 16 clinical cases

Alpha-human atrial natriuretic polypeptide (alpha-hANP) was applied to 16 clinical patients, 6 patients with essential hypertension, 7 patients with congestive heart failure and 3 patients with cirrhosis. Following intravenous bolus injection of 400 micrograms of synthetic alpha-hANP, a hypotensive effect of very rapid onset was found, which was more potent in the hypertensive patients than in the normotensive cases. Cardiac functions were improved significantly with a similar time course as the depressor response in the cases of heart failure or hypertension. Hemodynamic observations showed a marked increase in cardiac output, cardiac index, stroke volume, ejection fraction and ejection rate, and a concomitant decrease of the pressure in the right side of the heart and pulmonary circulation in these subjects. In addition, the renal response to alpha-hANP induced obvious increases in urine volume, electrolytes and creatinine excretions in all the subjects. Finally, plasma levels of aldosterone, Arg-vasopressin and noradrenaline were also altered by alpha-hANP. No significant side effects were registered. The above result confirms the therapeutic actions of alpha-hANP in human subjects and opens the possibility to research alpha-hANP as a powerful pharmacological tool as well as potential new medicine for human disorders.

Relationship between salt excretion and blood pressure in various regions of China: Part 2

Overnight urine samples were collected on three consecutive days from 2483 persons in 12 regions of China and the mean 9-hour overnight sodium and potassium levels subsequently determined. Analysis of the data by univariate regression, simple correlation, and multiple regression indicated that there was a positive correlation between the mean level of sodium in urine and blood pressure.

Relationship between salt excretion and blood pressure in various regions of China

Overnight urine samples were collected on three consecutive days from 3105 persons in 12 regions of China, and analysed for levels of sodium and potassium. The mean 9-hour overnight urine sodium level ranged from 49.51 to 139.12 mmol, and urine potassium from 6.32 to 18.43 mmol. Univariate regression, simple correlation analysis, and multivariate ridge regression analysis were carried out on the data. A positive correlation between blood pressure and urine sodium or sodium/potassium ratio was found in each of the twelve regions. Urine potassium showed a negative correlation with blood pressure in three regions.

The Red function of phage lambda mediates the alteration of an interspersed repeated DNA sequence from the kangaroo rat Dipodomys ordii

The kangaroo rat D. ordii is shown to contain an interspersed repeated sequence 3.25 kb in length. This sequence undergoes alteration (deletions) when cloned into a Red+ lambda vector but is stable in a Red- vector. Using the Red- clone it is shown that deletions are the result of the activity of the lambda Red, or E. coli RecE, recombination systems. Mixed infection experiments demonstrate that this activity is acting in trans. The deletions appear to yield fragments of specific size, suggesting that the recombination system is recognizing a specific sequence. The demonstration of small homologous fragments in the animal genomic DNA suggests that a similar system of recombination may exist in D. ordii.