Cardiovascular research
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Cardiovascular research · Feb 1978
Anterior pituitary response to thyrotrophin-releasing hormone during open-heart surgery.
The anterior pituitary response to thyrotrophin-releasing hormone has been studied in 20 patients submitted to elective open-heart surgical procedures, and in six control patients submitted to closed mitral valvotomy. Standard non-pulsatile normothermic perfusion was used in all the open-heart cases. 400 microgram thyrotropin-releasing hormone was administered by intravenous injection during bypass, at 30 min post-bypass, and at 60 min post-bypass. ⋯ Thyrotrophin-releasing hormone given after the period of bypass produced responses within the normal range in the majority of patients. These results suggest that anterior pituitary hypofunction may exist during the period of extracorporeal circulation using non-pulsatile perfusion and that recovery of pituitary function is evident within the first hour post-extracorporeal circulation.
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Cardiovascular research · Nov 1977
Failure of saralasin acetate, a competitive inhibitor of angiotensin II, to diminish alveolar hypoxic vasoconstriction in the dog.
The role of angiotensin II in the pulmonary vasoconstriction induced by alveolar hypoxia was investigated with the competitive inhibitor of angiotensin, saralasin acetate. Unilateral alveolar hypoxia was induced in dogs by ventilation of one lung with 100% N2 through a double lumened endotracheal cannula while maintaining adequate systemic oxygenation by ventilating the other lung with 1oo% O2. Pulmonary perfusion was monitored with 133Xe and external detectors. ⋯ After infusion of 6--24 microgram.kg-1/min of saralasin acetate, beginning 2 min before the alveolar hypoxic challenge and continuing through it, unilateral alveolar hypoxia continued to reduce perfusion to that lung by 28.8% (P = 0.6 from control). In 2 dogs a higher infusion of 60 microgram.kg-1/min failed to reduce the alveolar hypoxic vasoconstriction and in 2 dogs a 15 min infusion of 6 microgram.kg-1 of saralasin acetate before alveolar hypoxia and continuing through it, still failed to inhibit alveolar hypoxic vasoconstriction. Thus, no role was demonstrated for angiotensin II in acute alveolar hypoxic vasoconstriction of the dog.
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Cardiovascular research · Mar 1976
Effects of phenobarbitone, cinnarizine, and zoxazolamine on the development of right ventricular hypertrophy and hypertensive pulmonary vascular disease in rats treated with monocrotaline.
The results of this experiment suggest that the addition of zoxazolamine to the diet may prolong the survival and reduce the incidence of right ventricular hypertrophy and hypertensive pulmonary vascular disease in male rats given a single subcutaneous injection of monocrotaline. Phenobarbitone and cinnarizine were ineffective.