SYMPATHOLYTIC DRUGS AND HYPERLIPAEMIA INDUCED IN RATS BY INTRAPERITONEAL INJECTIONS OF SURFACE-ACTIVE AGENT

Hyperlipaemia and hypercholesterolaemia were induced in white rats by intraperitoneal injections of tyloxapol. Various sympatholytics and adrenolytics, including blocking agents of beta-receptors, were given simultaneously with tyloxapol. Bretylium tosylate prevented the increase in the serum levels of esterified fatty acids and cholesterol caused by tyloxapol. Phentolamine decreased the enhancement by tyloxapol of cholesterol and total lipid concentrations in the serum. Guanethidine and phenoxybenzamine reduced the increase in the concentration of esterified fatty acids, whereas dichloroisoprenaline insignificantly increased the tyloxapol-induced hyperlipaemia. A small dose of pronethalol slightly increased the esterified fatty acid level in tyloxapol-treated animals; a large dose significantly decreased the serum cholesterol concentration.

Pressor Responses to Noxious Stimuli in Hypertensive Patients

The pressor and pulse rate responses to several standardized stimuli were determined in hypertensive patients receiving guanethidine sulfate or alpha methyldopa in therapeutic doses. Despite differences between the two compounds in their mode of action, both demonstrated functionally sympatholytic effects. Both drugs produced a greater blood pressure fall in the erect posture than in the supine and impaired the pressor response to the cold pressor test. The pressor reactivity to intravenous angiotensin, however, persisted. Responses to psychophysiologic stimuli were decreased. The implications of these findings for both therapy and for understanding of physiologic mechanisms of pressor reactivity are discussed.

EFFECT OF DIET, POSTURE, AND GUANETHIDINE ON TCH2O IN HYPERTENSIVE SUBJECTS

Studies of renal function in four hypertensive patients under various conditions of diet, therapy, and position were undertaken in an effort to clarify their relationship to THH2Oc and to further illucidate the mechanism by which THH2Oc is altered. The results indicate that the decrease of THH2oc induced by a low-salt diet is not due to the concomitant decrease of glomerular filtration rate, clearance of sodium, or sodium load to the loop of Henle. Acute decrease of GFR by standing position is accompanied by a significant increase of THH2oc. It was also shown that the modification of ! occurred apparently independently of the variations in renal plasma flow. Finally it was not possible, in our patients, to detect the actual mechanism by which a low-salt diet decreased THH2oc.

recumbent and standing position; normal diet; Na-deficient diet

Submitted on August 8, 1963

RENAL ISCHAEMIA DUE TO THROMBOSIS OF RENAL ARTERY RESULTING FROM METASTASES FROM PRIMARY CARCINOMA OF THE BRONCHUS

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