Endogenous angiotensin II in the regulation of hypoxic pulmonary vasoconstriction in anaesthetized dogs

INTRODUCTION: The role played by several vasoactive mediators that are synthesized and released by the pulmonary vascular endothelium in the regulation of hypoxic pulmonary vasoconstriction (HPV) remains unclear. As a potent vasoconstrictor, angiotensin II could be involved. We tested the hypothesis that angiotensin-converting enzyme inhibition by enalaprilat and type 1 angiotensin II receptor blockade by candesartan would inhibit HPV. METHODS: HPV was evaluated in anaesthetized dogs, with an intact pulmonary circulation, by examining the increase in the Ppa–Ppao gradient (mean pulmonary artery pressure minus occluded pulmonary artery pressure) that occurred in response to hypoxia (inspiratory oxygen fraction of 0.1) at constant pulmonary blood flow. Plasma renin activity and angiotensin II immunoreactivity were measured to determine whether activation or inhibition of the renin–angiotensin system was present. RESULTS: Administration of enalaprilat and candesartan did not affect the Ppa–Ppao gradient at baseline or during hypoxia. Plasma renin activity and angiotensin II immunoreactivity increased during hypoxia, and subsequent measurements were consistent with effective angiotensin-converting enzyme inhibition after administration of enalaprilat, and with angiotensin receptor blockade after administration of candesartan. CONCLUSION: These results suggest that, although the renin–angiotensin system was activated in hypoxia, angiotensin II is not normally involved in mediating acute HPV

Relationships between blood pressure, heart rate and plasma epinephrine, norepinephrine, angiotensin II concentrations, plasma renin activity during chronic guanfacine therapy in patients with essential arterial hypertension

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Amniotic fluid embolism: Another case with non-cardiogenic pulmonary edema

SCOPUS: le.jinfo:eu-repo/semantics/publishe

Effect of sotalol on haemodynamics and renin angiotensin aldosterone system in hypertensive patients

Twenty three hypertensive patients were treated by sotalol, a pure beta adrenergic receptor blocking agent. The drug produced a significant decrease of blood pressure in 19 patients. On an average, cardiac index decreased but not significantly; heart rate decreased and stroke index increased significantly. Total peripheral resistance varied in both directions. Sotalol determined a fall in plasma renin concentration (only significant in the high renin group), a fall in plasma angiotensin II concentration and in urinary excretion rate of aldosterone accompanied by a rise in the plasma potassium concentration. The fall of blood pressure was not correlated with the decreases of renin and angiotensin II concentrations or excretion rate of aldosterone. However, in the placebo period plasma angiotensin II concentration was significantly correlated with total peripheral resistance; during sotalol treatment the variations of these two parameters seemed also to be correlated. There was a poor correlation between decreases of cardiac output and of blood pressure; it was impossible to foresee the magnitude of the lowering of the blood pressure from the initial cardiac index. The association of a diuretic with sotalol enhanced the hypotensive effect of the beta receptor blocking drug, without significant increase of plasma renin and angiotensin II concentrations.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

LE SYNDROME DE SEVRAGE A L'ARRET DES MEDICAMENTS HYPOTENSEURS

A discontinuation syndrome can be observed at the cessation of treatment in hypertension. Its clinical picture resembles the hypertensive crisis of pheochromocytoma. Its physiopathology, risk factors and treatment are reviewed.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Intoxications par disulfiram et éthanol

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Torsades de pointes due to methadone.

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Effect of low doses of angiotensin II perfusion on the hypotensive action of captopril in anaesthetized normotensive and spontaneously hypertensive rats

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Assessment of a plasma ADH radioimmunoassay in experimental and physiologic or pathologic conditions

A radioimmunoassay of ADH has been applied to the study of plasma ADH levels in various conditions. The validity of the assay has been evaluated by the usual quality control parameters of RIA and by the measure of plasma levels in 12 upright water deprived normal volunteers (mean 9.5 pg/ml, SEM ± 1.5), in 8 resting and hydrated normal volunteers (1.3 ± 0.4 pg/ml), in a case of diabetes insipidus (1.6 pg/ml), in 8 cases of SIADH Syndrome (range 13-77 pg/ml) and in 4 anesthetized dogs before (33.7 ± 9.2 pg/ml) and after acute haemorrhage (66 ± 9.5 pg/ml, p < 0.02). The osmotic challenge to ADH secretion has been studied in 8 patients with no overt endocrine pathology by salt perfusion and showed a significant rise (p <0.05) of plasma ADH from 6.3 ± 3.1 pg/ml before, to 20.6 ± 7.9 pg/ml during salt infusion corresponding to the significant (p < 0.0001) rise of plasma osmolality from 273 ± 2.8 to 288.2 ± 1.1 mOsm/kg.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Effects of Sotalol on the isolated dog kidney functions

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