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Biomedical subjects

H E Eliahou

Publications and source records attributed to H E Eliahou.

At least 19 recordsLinked to original sources

Hyperinsulinemia induces myocardial infarctions and arteriolar medial hypertrophy in spontaneously hypertensive rats.

To investigate the effects of hyperinsulinemia on the myocardial vessels, long acting insulin (mixtard, a combination of 30% regular human insulin and 70% NPH human insulin) was injected daily for 8 weeks, intraperitoneally, in two strains of rats, normotensive WKY and hypertensive SHR. There were four groups in all, a control group, and an insulin-injected group in each strain. The drinking water contained 10% glucose to prevent hypoglycemia in the insulin-injected rats. At the end of the 8 weeks experimental period, after measuring blood pressure and taking blood for the determination of glucose, urea, creatinine, and insulin, the rats were killed. The organs were fixed in formaldehyde. The blood glucose levels were higher at the end of the experiment, in both the placebo- (saline)-injected and the insulin-injected rats. Blood pressure rose significantly only in the insulin-injected SHR. The intramyocardial arterioles in the insulin-injected SHR had a significantly thicker vascular wall than the placebo-injected SHR, as represented by the vessel wall to lumen ratio, because of hypertrophy of the media. When compared with the placebo injected WKY rats, there was a higher wall/lumen ratio of the intramyocardial arterioles in the insulin-injected WKY, but the difference did not reach significance. Heart weights factored by body weights was significantly higher in insulin-injected as compared with placebo-injected SHR. Myocardial infarctions were observed in four of eight rats in the insulin-injected SHR group despite the fact that there were no signs of atherosclerosis or intimal thickening. It is possible that the increase in heart weight and the probable increase in metabolic activity resulting from hyperinsulinemia, together with the increased oxygen demand of the myocardium and the arteriolar narrowing, may have contributed to the occurence of myocardial infarctions in the absence of atherosclerotic coronary occlusion.

Animals↗

Insulin induces medial hypertrophy of myocardial arterioles in rats.

To investigate the effect of hyperinsulinemia on arteriolar hypertrophy, myocardial hypertrophy, and blood pressure, we administered insulin intraperitoneally to SHR and WKY rats for 3 consecutive weeks. To prevent hypoglycemia, the drinking water contained 10% sugar, and to accentuate the blood pressure, their chow contained 8% table salt. Blood pressure was measured by the tail-cuff method. Heart weights were factored with body weights. Arterioles of approximately 100 microns in diameter were examined at the end of the experiment and the vascular wall thickness was factored with the lumen diameter. At the end of 3 weeks, blood pressure rose in the SHR but not in the WKY rats. The heart weights in the WKY normotensive rats did not increase, whereas in the SHR they did. Furthermore, there was a significant rise in vessel wall thickness in the rats that received insulin, whether there was a rise in blood pressure or not and whether they had an increase in heart weight or not. There was a similar rise in blood glucose in all the groups, with slightly more accentuated rise in the SHR that received insulin. Nevertheless the increase in vascular wall thickness occurred only in the groups which received insulin. This seems to preclude the importance of hyperglycemia per se as the causative agent for the increase in vascular wall thickness in this study. The increase was in the form of medial hypertrophy without any sign of atherosclerosis. It seems, therefore, that hyperinsulinemia is associated with hypertrophy of the media of arterioles regardless of the increase in heart weight or the rise in blood pressure.

Animals↗

Cardiovascular effects of nisoldipine in essential hypertension.

The acute hemodynamic effects of nisoldipine (Bay K552) in patients with essential hypertension were studied using nuclear ventriculography. In a cohort of 16 essential hypertension patients, an oral dose of 15 mg nisoldipine significantly lowered blood pressure within 20 min. The effect lasted at least 3 h. Blood pressure that was 160.5 +/- 20.3/108.0 +/- 10.1 mm Hg initially was reduced to 137.0 +/- 14.9/93.8 +/- 9.4 mm Hg at 3 h (P < 0.001). Cardiac output rose, total peripheral resistance fell and ejection fraction rose significantly. End systolic and end diastolic volumes did not change significantly with this dose of nisoldipine. The acute hemodynamic effects of 15 mg nisoldipine administered orally, measured by repeat nuclear ventriculography, were maintained during therapy for the 8 weeks of observation. Thus, nisoldipine is a powerful antihypertensive agent, significantly decreasing BP as well as total peripheral resistance and increasing cardiac index. This effect was prominent after 3 h and wore off about 12 h after each dose. Five of the patients had an initially high heart rate. To these patients propranolol was added in small doses (20-40 mg/day, mean 25 +/- 26 mg/day). This addition did not change the results when the patients were analyzed separately.

Administration, Oral↗

Glycerol induced ARF in rats is mediated by tumor necrosis factor-alpha.

Glycerol-induced acute renal failure (ARF) in rats is a model of acute trauma in which intra-muscular injection of 50% glycerol causes rapid myoglobinuria, oliguria, and a rapid reduction in glomerular filtration rate. We found that plasma tumor necrosis factor-alpha (TNF-alpha) is rapidly induced in glycerol injected rats. It can be detected in some animals as early as 30 minutes post-injection, peaks at one hour (range: 4 to 32 U/ml) with no significant difference between blood from renal vein and vena cava, and decreases by three hours. None was detected in control saline injected rats (P < 0.001). Four out of five rats infused with neutralizing anti-TNF-alpha antiserum (200 microliters/300 g body wt) immediately prior to glycerol injection had significantly protected kidney function (P = 0.001). In these rats, plasma urea (104.8 +/- 58.9 mg%) and creatinine (1.16 +/- 0.38 mg%) were lower and creatinine clearance higher (0.34 +/- 011 ml/min) than in glycerol injected animals pretreated with normal serum (291.8 +/- 41.8 mg%, 3.15 +/- 0.74 mg%, and 0.03 +/- 0.03 ml/min, respectively) or animals injected with glycerol alone (302.6 +/- 76.8 mg%, 3.45 +/- 0.97 mg%, and 0.03 +/- 0.03 ml/min, respectively). These results imply a direct role for TNF-alpha in pathogenesis of glycerol induced ARF in rats.

Acute Kidney Injury↗

Successful pregnancy in a patient with polycystic kidney disease and advanced renal failure: the use of prophylactic dialysis.

Adult polycystic kidney disease is an inherited disease that is transmitted as an autosomal dominant trait. The clinical manifestations, which develop during the third or fourth decade of life, usually do not affect women during childbearing age and thus do not affect fertility or pregnancy outcome. The patient presented here had polycystic kidney disease and advanced renal failure, and was treated with meticulous fetal surveillance and prophylactic hemodialysis during pregnancy. The successful outcome strengthens the trend to perform prophylactic dialysis in pregnancies with advanced renal failure, despite the lack of controlled studies.

Adult↗

Effect of low-calorie diets on the sympathetic nervous system, body weight, and plasma insulin in overweight hypertension.

When weight reduction was found to decrease blood pressure in the overweight hypertensive patient, it was hailed as the causative factor. A growing number of recent studies indicate that this association may be secondary to a correlation between diet-associated metabolic change and the sympathetic nervous system. A select group such as overweight hypertensive patients may have a genetic predisposition for such a correlation. In overweight hypertensive patients, low-calorie diet and especially very-low-calorie diet, correlate with improved glucose metabolism, a decrease in plasma insulin concentration, and altered norepinephrine concentrations and thus sympathetic nervous system activity. Several of these studies also show a lack of effect of salt intake on blood pressure. Thus, it seems that metabolic changes caused by the decrease in caloric intake are responsible for the decrease in blood pressure. These must be investigated to understand the effect of the different diets on blood pressure. Very low-calorie diets were found very useful in breaking the vicious circle of severe nonresponsive hypertension to medication.

Blood Pressure↗

Effect of nisoldipine on ambulatory blood pressure under 24-hour noninvasive monitoring.

The antihypertensive effect of nisoldipine on ambulatory blood pressure was investigated using continuous noninvasive monitoring in 12 patients with moderate essential hypertension. Treatment with nisoldipine 5 mg twice a day for 2 weeks resulted in a decrease in the average of each patient's mean arterial pressure for the whole day from 110.3 +/- 6.8 to 103.2 +/- 8.8 mm Hg (P = 0.0007). This decrease in mean arterial pressure was due to a decrease in both systolic and diastolic pressures. The reduction in blood pressure was most marked at the time of the originally high blood pressure readings. Comparisons of consecutive means of 2-hourly mean arterial pressure readings showed a statistically significant effect from 6:00 AM to midnight. Blood pressures between midnight and 6:00 AM were similarly low, before and during nisoldipine therapy. There was no change in heart rate. Untoward symptoms were reported with similar frequency, and of similar severity, both before and during therapy. Nisoldipine 5 mg twice a day is an effective antihypertensive agent, reducing moderately elevated blood pressure in ambulatory, working patients with essential hypertension. At the dosage used, it had no demonstrable effect on heart rate and minimal, if any, side effects.

Adult↗

Calcium channel blocker nisoldipine in chronic renal failure.

Patients with a stable progression of chronic renal failure with a creatinine clearance of 15-45 mL/min were randomly assigned to two groups of antihypertensive therapy: 1--nisoldipine as the only antihypertensive agent and 2--antihypertensive drugs without calcium channel blockers and a placebo tablet instead of nisoldipine. The patients were already on a low-protein diet and some form of antihypertensive therapy but without calcium channel blockers. There were 18 patients in the placebo group and 20 patients in the nisoldipine group. The follow-up period averaged 23.7 +/- 10.6 (SD) months in the placebo group and 23 +/- 11.3 months in the nisoldipine group. The slopes of the reciprocal of serum creatinine were calculated for the period prior to and following our intervention. The number of patients whose slopes improved following intervention was 6/18 in the placebo group and 15/20 in the nisoldipine group (p less than .02). The patients whose slopes improved had a significant fall in systolic and diastolic BP, as well as in the MAP. Those whose slopes did not improve had a significant decrease in systolic BP, but no change in diastolic BP and no significant difference in the MAP. When all 38 patients are analyzed together, regardless of their grouping, the correlation between the difference percent in the slope, and the difference percent in the MAP, was significant. Furthermore, punch biopsies of the skin showed a markedly different calcium content in the two groups, which was significantly less in the nisoldipine-treated patients as compared with the patients not receiving calcium blockers.(ABSTRACT TRUNCATED AT 250 WORDS)

Antihypertensive Agents↗

Energy restriction or salt restriction in the treatment of overweight hypertension. Which one? A point of view.

Body weight reduction in the overweight hypertensive patient was found to reduce blood pressure, irrespective of the daily urinary sodium excretion. Significant blood pressure reductions were achieved while the urine sodium excretion was between 165-185 mEq/day. Salt restriction resulting in a significant decrease of the 24-hour urine sodium from 192-110 mEq/24-hours did not change the blood pressure. Some of the studies indicating a reduction in blood pressure, did not take into account the changes in body weight, while on sodium restriction. Thus sodium restriction in the treatment of hypertension has not been uniformly found to reduce the blood pressure. Although there is much evidence in favour of the involvement of sodium in the regulation of blood pressure, there is no convincing evidence that dietary sodium restriction can be of use as a therapeutic modality in the treatment of hypertension in the overweight hypertensive patient.

Blood Pressure↗

The calcium channel blocker nisoldipine delays progression of chronic renal failure in humans (preliminary communication).

Chronic renal failure (CRF) patients with a stable course were asked to participate in a follow-up program in which they were randomized into two groups: 1) the placebo group taking their standard antihypertensive therapy without any calcium ion blocker: and 2) the nisoldipine group, those patients taking the calcium channel blocker nisoldipine as the only antihypertensive drug. The two groups had similar blood pressures on entering the study (151 +/- 21.3/90.7 +/- 7.4 mmHg in the nisoldipine and 146.7 +/- 18/94 +/- 9.4 mmHg in the placebo group). Their protein intake was also similar (daily average throughout the follow-up period: 0.83 +/- 0.18 g protein per kg body weight in the nisoldipine and 0.9 +/- 0.12 g in the placebo group). The patients were checked monthly. The follow-up averaged 11.1 +/- 4.8 months in the nisoldipine group and 13.7 +/- 4.2 months in the placebo group. The rate of progression of CRF, as expressed by the slope of the regression line of 1/serum creatinine versus time, decreased in the nisoldipine group from the initial (-8.03 +/- 4.91) x 10(-3) to (-5.57 +/- 5) x 10(-3) (two-tailed P-test = 0.016) after intervention. The slopes tended to become steeper in the placebo group, with an initial slope of (-4.1 +/- 3.2) x 10(-3) changing to (-7.9 +/- 5) x 10(-3) after intervention. This difference did not reach statistical significance (two-tailed P = 0.072). The rate of progression of CRF decreased in 12 of 14 patients in the nisoldipine-treated group versus 3 of 11 patients in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effect of the calcium channel blocker nisoldipine on the progression of chronic renal failure in man.

Patients with stable renal insufficiency were randomized into two groups: (1) patients given the channel blocker nisoldipine (n = 17) and (2) placebo-treated patients (n = 17) also taking their regular antihypertensive therapy which did not include calcium blockers. Patients were already on low protein diet with a protein intake of 0.80 +/- 0.2 in the nisoldipine group versus 0.85 +/- 0.25 g/kg body weight in the placebo-treated group. The monthly progression of their renal failure was assessed by the reciprocal of serum creatinine versus time in months. After a mean follow-up of 17.4 +/- 8.2 (range 6-30) months, the nisoldipine-treated group had a significant decrease in their slope of progression, whereas the placebo-treated patients, after 16.94 +/- 7.2 (range 6-30) months of follow-up, had no significant change in their slope. The protein intake during follow-up was similar, being 0.85 +/- 0.2 g/kg actual body weight in the nisoldipine-treated group and 0.88 +/- 0.26 g/kg in the placebo group. The changes in slope did not correlate with the changes in blood pressure.

Adult↗

The control of hypertension and its effect on renal function in rat remnant kidney.

Blood pressure control and its influence on the rat remnant kidney function were studied. The deterioration in kidney function was followed for up to 20 weeks at 4-weekly intervals in four groups of 5/6th nephrectomised rats. The groups studied were: (1) Control, untreated (C), given normal rat chow containing 21% protein; (2) nisoldipine (a dihydropyridine calcium channel blocker) treated (N), given nisoldipine freshly mixed daily in normal chow (0.3-0.6 mg/kg body weight); (3) dihydralazine-treated (H), fed normal chow and given dihydralazine added daily to the drinking water, about 15-25 mg/kg body weight daily; and (4) low-protein (6%) diet (LP), isocaloric and having the same sodium content as the normal chow. Proteinuria, serum creatinine, blood urea, histological damage as seen by light microscopy, and cumulative survival were taken to assess the severity of the chronic renal failure. All three therapeutic regimens attenuated significantly the rise in blood pressure which developed within less than 4 weeks in the rats with the remnant kidney. At the 16th week, means +/- standard deviations were, in group C, 237 +/- 20 mmHg; group N, 147 +/- 20 mmHg; group H, 164 +/- 23 mmHg; and group LP 149 +/- 16. Systolic blood pressure at the 8th week had a significant correlation with the serum creatinine of the 12th and of the 16th weeks. There was a strong correlation between blood pressure and the serum creatinine at the 16th week. This indicates that a time lag is necessary for the hypertension to have an effect on kidney function. Proteinuria, serum creatinine and blood urea were much higher in the untreated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗