Search PubMed⌕ Search

Biomedical subjects

E D Freis

Publications and source records attributed to E D Freis.

At least 109 records · Page 6Linked to original sources
PubMed1976

Relative effectiveness of chlorothiazide, reserpine and hydrallazine in spontaneously hypertensive rats.

1. Previous studies in this laboratory indicated that a mixture of anti-hypertensive agents in the drinking water controlled the blood pressure of spontaneously hypertensive rats (SHR). The present study was designed to determine which of the agents exerted the greatest anti-hypertensive effect. 2. Treatment was begun at 12 weeks of age in groups of eleven to seventeen rats with one of the following drugs: reserpine, chlorothiazide or hydrallazine. Blood pressures were recorded by the tail method under light ether anaesthesia every 2 weeks until the rats were approximately 70 weeks of age. 3. At 50 weeks of age, blood pressure of chlorothiazaide-treated rats averaged 40 mmHg below untreated control SHR; reserpine-treated SHR were also 40 mmHg lower than control rats, and hydrallazine-treated SHR were 85 mmHg below the control rats. 4. Rats in all groups gained weight normally and appeared in good health. Although all drugs were active, hydrallazine was considerably more effective than chlorothiazide or reserpine in the SHR.

Animals↗
PubMed1976

Salt, volume and the prevention of hypertension.

The evidence supporting the thesis that hypertension can be prevented by eliminating salt from the diet is based on four principal sources: (1) epidemiological studies in unacculturated peoples showing that the prevalence of hypertension is inversely correlated with the degree of salt intake; (2) hemodynamic studies suggesting that the development of chronic experimental hypertension is a homeostatic response to a maintained increase in extracellular fluid volume (ECF); (3) evidence that the ECF of "salt eaters" is expanded in comparison to that of "no-salt eaters"; and (4) investigations in hypertensive patients receiving either diets greatly restricted in salt or continuous diuretic therapy which correlate the fall in blood pressure with a reduction in ECF. Although this mechanism of essential hypertension is still obscure the evidence is very good if not conclusive that reduction of salt in the diet to below 2 g/day would result in the prevention of essential hypertension and its disappearance as a major public health problem.

Adult↗
PubMed1976

Renomedullary interstitial cells in the spontaneously hypertensive rat.

Renomedullary interstitial cells (RIC) are known to synthesize and release prostaglandins which may play a significant role in the development or severity of hypertension. The medulla of the spontaneously hypertensive rat contains RIC which are morphologically very similar to those previously described in the normotensive rat. The granularity of the RIC, however, was increased in the spontaneously hypertensive rat compared to normotensive Wistars (9.6 +/- 2.34 versus 5.3 +/- 2.05 granules per cell, respectively, p less than 0.001) or treated spontaneously hypertensive rats (7.2 +/- 1.65 granules per cell, p less than 0.001). Granule counts also increased in the presence of mild and moderate degrees of renal arteriolar sclerosis, but decreased in long standing hypertension with more severe and extensive lesions involving both arteries and arterioles. These results are consistent with the hypothesis that the RIC respond to an elevation of blood pressure in the spontaneously hypertensive rats by increased release of antihypertensive substances. In addition, the decrease in granularity of the RIC in the presence of extensive renal arteriolar and arterial damage suggests reduced ability to compensate for the elevated blood pressure and thus may contribute to the acceleration of hypertension.

Aging↗
PubMed1975

Normal cardiac output during beta blockade with timolol in hypertensive patients.

Data published by this laboratory indicated that the beta adrenergic blocking drugs timolol and propranolol exerted equivalent beta blocking and antihypertensive actions in patients with mild essential hypertension, but that whereas cardiac output fell acutely with both drugs, it returned to normal after 5 wk of treatment with timolol, but remained depressed after propranolol. This preliminary observation needed further confirmation in a larger series of patients. In this study, 11 patients with initial diastolic blood pressures between 90 and 125 mm Hg were given timolol for 5 wk. Hemodynamic measurements were made before and at the end of treatment. Mean heart rate fell from 76.8 to 64.3 bpm (p less than 0.001), and blood pressure was reduced from 179.4/99 mm Hg to 167.4/93.3 mm Hg (less than 0.02). Cardiac output averaged 6.29 L/min before timolol, and fell to 5.95 L/min (NS) after treatment. Stroke volume increased significantly, while total peripheral resistance was unchanged. These results confirm our earlier observations that timolol is an effective beta adrenergic blocking drug with antihypertensive action that does not reduce cardiac output significantly when given chronically. This drug merits further evaluation in other cardiovascular disorders since it may have advantages over other beta adrenergic blocking drugs.

Adrenergic beta-Antagonists↗
PubMed1975

Partial versus complete control of blood pressure in the prevention of hypertensive complications.

The data from the Veterans Administration Cooperative Study on Antihypertensive Agents Prevention of Morbidity Trial were reviewed from the point of view of the importance of normalizing the blood pressure in preventing cardiovascular complications. The treated group of patients was subdivided into three subgroups on the basis of the diastolic blood pressures recorded at the fourth month after randomization as follows: subgroup A, the poorly controlled patients whose diastolic blood pressures were 90 mm Hg or higher, an intermediate subgroup B with diatolic levels of 81 to 89 mm Hg, and subgroup C, the best controlled patients, all of whom exhibited diastolic blood pressures of 80 mm Hg or less. While the incidence of morbid events was slightly higher in subgroup A than in the other subgroups, the differences were not statistically significant. On the other hand, the incidence of morbid events in subgroup A was significantly lower (P less than 0.05) than in the untreated control patients (14.9% in subgroup A vs. 28.9% in the control group). While normalization of blood pressure is a desirable goal of treatment, even partial reduction appears to exert significant therapeutic benefit.

Atrial Fibrillation↗
PubMed1975

Effect of treatment on longevity in spontaneously hypertensive rats.

Continuous control of the pressure of spontaneously hypertensive rats at systolic levels of 90-100 mm Hg with antihypertensive agents significantly prolonged their life span. The mean survival time in control animals was 73 weeks as compared to 96 weeks in treated SHR (P less than .0005) with 11% of the latter surviving to approximately 3 yr of age. Cardiovascular lesions were limited almost exclusively to the control rats. The general health, body weight and reproductive functions of the experimental animals remained normal throughout the drug treatment. These results indicate that by preventing the rise in blood pressure and consequent cardiovascular complications the life span of the SHR may be prolonged to that of the normal albino rat.

Animals↗