The effect of acute administration of chlorothiazide upon the pressor responsiveness to angiotensin and norepinephrine

Silah, Jack G.; Jones, Richard E.; Bashour, F.A.; Kaplan, Norman M.

doi:10.1016/0002-8703(65)90269-3

Cited by 18 publications

(3 citation statements)

References 14 publications

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“…Vascular reactivity to noradrenaline (Silah, Jones, Bashour 8z Kaplan, 1965) was studied in all patients. Infusion of 0-278 moll1 (5%) glucose in water was begun in an antecubital vein and the intra-arterial blood pressure was checked.…”

Section: Methodsmentioning

confidence: 99%

“…It seems more likely, as suggested by the work of Folkow & Mellander (1964), that the intrathoracic shift was related to abnormal venous tone and sympathetic activity. Previous reports suggest such an interpretation since, first, the sympathetic nervous system has been shown to play a major part in the regulation of cardiopulmonary blood volume (Forsberg, 1964) and, secondly, increases of sympathetic tone and of vascular reactivity to noradrenaline have been described in hypertension, especially in the borderline state (Goldenberg, Pines, Baldwin, Greene & Roh, 1948;Doyle & Smirk, 1955;McCubbin & Page, 1963;Tarazi & Dustan, 1973).…”

Section: Cpbvltbv Ratio In Borderline Hypertensionmentioning

confidence: 95%

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Cardiopulmonary Blood Volume in Borderline Hypertension

et al. 1974

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S U M M A R Y1. A haemodynamic study which included estimation of cardiopulmonary blood volume (CPBV), total blood volume (TBV) and vascular reactivity to noradrenaline was performed in seventeen borderline and sixteen permanent hypertensive patients.2. Borderline hypertensive patients had higher values of cardiac index, stroke index and heart rate when compared with the permanent hypertensive patients, and lower values of blood pressure and total peripheral resistance.3. The CPBVITBV ratio was significantly higher in borderline hypertensive patients. In that group, this ratio was directly correlated with cardiac index, stroke index and the pressor dose of noradrenaline (P ~0.01). 4. In permanent hypertensive patients, none of these correlations was observed.Only the total blood volume was correlated directly with cardiac index and inversely with total peripheral resistance. 5.The study suggests that a redistribution of intravascular volume from peripheral veins to the cardiopulmonary capacitance bed occurs in borderline hypertension when compared with permanent hypertension and that hypertension is related to a neural mechanism in the borderline state and to a volume mechanism in the permanent state.

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Section: Methodsmentioning

confidence: 99%

Section: Cpbvltbv Ratio In Borderline Hypertensionmentioning

confidence: 95%

Cardiopulmonary Blood Volume in Borderline Hypertension

et al. 1974

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“…Winer, however, did not find such a difference in response in human hypertensives (18). The acute intravenous administration of chlorothiazide does not block the constrictor action of either norepinephrine or angiotensin II when these substances are administered as an infusion at the same time as an infusion of thiazide (39,40). This would suggest that the diuretic aspect of the thiazide drugs is necessary for blunting the vasoconstrictor action of nor epinephrine.…”

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confidence: 95%

Why Do Thiazide Diuretics Lower Blood Pressure in Essential Hypertension?

Tobian¹

1967

Annu. Rev. Pharmacol.

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This review must have an aura of apology about it, since it does not deliver the genuine nugget which is our goal. Oral diuretics, such as the thiazides or chlorthalidone, will indubitably lower the blood pressure of most patients with essential hypertension (1, 2). There are more than a hun dred medical articles attesting to this. Since the author treats hypertensive patients, he can abundantly confirm these reports. In moderately large doses, these drugs by themselves will drop the blood pressure of most patients with primary hypertension. Furthermore, these drugs enhance the antihyperten sive effect of all other hypotensive drugs. In this review an attempt will be made to explain this important drug effect, but the ultimate explanation is still lacking (hence, the apology).The pure effect of these drugs can best be brought out when they are used alone. If the diuretic agents are taken daily by mouth at a dose level which produces a half maximal or three-fourths maximal diuresis, the blood pressure of hypertensive patients gradually begins to drop, and after two weeks it is often 30 mm lower in systolic pressure and 20 mm lower in diastolic pressure. With continued administration of the drug, the blood pressure is maintained at the lower level almost indefinitely. Very little tolerance to the drug is seen. Additional antihypertensive drugs can be sub sequently added to the regimen and their effect is enhanced in the presence of the thiazide medication.When the thiazides are first administered, they have their usual diuretic action and there is an increased excretion of sodium and water. In some parts of the renal tubule, there is a diminished reabsorption of filtered so dium and water, which leads to the diuresis. The mechanism here is in dis pute. Dirks et al. (3) have noted in micropuncture studies of dog kidney that inulin concentrations in proximal tubular fluid are the same in thiazide treated dogs as in non treated controls. This would suggest that the actual "diuresis" is not occurring in the proximal convoluted tubule. On the other hand, Ullrich (4), using the split-oil-droplet technique in micropuncture studies, finds that thiazide diuretics greatly diminish the reabsorption of sodium and water from segments of proximal convoluted tubule. There is a way to reconcile partially these seemingly opposite views. It is quite possible

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Hemodynamic and Humoral Effects of Chronic Antihypertensive Treatment with Fenquizone: Importance of Aldosterone Response

Costa

Borghi

Boschi

et al. 1990

The Journal of Clinical Pharma

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The effects of 1-year antihypertensive treatment with the diuretic fenquizone were evaluated in 16 patients with mild essential hypertension. During treatment with placebo, after 2, 4, 24, and 52 weeks of treatment we measured blood pressure, heart rate, forearm blood flow (FBF) and vascular resistance (FVR) at rest and after 10 minutes ischemia, and forearm venous distensibility. Subjects whose diastolic blood pressure after fenquizone was reduced at least 10% were classified as responders. On this basis, 56% of patients after 1 month and 68% after 1 year responded to fenquizone. Responders, in comparison to nonresponders, were characterized by a greater increase in FBF and a greater decrease in FVR. The reduction in diastolic blood pressure was significantly related to the fall in FVR whereas no correlation was found between blood pressure and venous compliance changes. Nonresponders had a PRA increase similar to that observed in responders but they showed a much greater increase in aldosterone, whose changes were inversely related to modifications of both FVR and blood pressure. Our results demonstrate that chronic therapy with fenquizone causes a reduction of FVR, and that nonresponders have an exaggerated rise in aldosterone. This observation further reinforces the hypothesis that factors influencing the secretion of aldosterone are important determinants of the antihypertensive mechanism of diuretics.

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The effect of acute administration of chlorothiazide upon the pressor responsiveness to angiotensin and norepinephrine

Cited by 18 publications

References 14 publications

Cardiopulmonary Blood Volume in Borderline Hypertension

Cardiopulmonary Blood Volume in Borderline Hypertension

Why Do Thiazide Diuretics Lower Blood Pressure in Essential Hypertension?

Hemodynamic and Humoral Effects of Chronic Antihypertensive Treatment with Fenquizone: Importance of Aldosterone Response

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