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Biomedical subjects

W A Rolston

Publications and source records attributed to W A Rolston.

4 recordsLinked to original sources

Echocardiographic appearance of ruptured aortic cusp.

Serial echocardiograms of a patient with enterococcal endocarditis and aortic insufficiency suggested the presence of vegetations on the aortic valve with progression of the lesion to frank prolapse of an aortic valve cusp. At surgery, the patient was found to have a flail noncoronary cusp to which an 8 mm vegetation was adherent. Anatomic correlations are presented, and a possible mechanism for the unusual echographic findings is discussed.

Adult

The role of adrenergic receptor blockade in serotonin-induced changes in the pulmonary circulation.

1. In dogs i.v. injection of serotonin caused a rise in pulmonary artery pressure and pulmonary arteriocapillary resistance that persisted even after alpha- and beta-adrenergic receptor blockade; pulmonary venous resistance also increased, but this was abolished by pretreatment with either propranolol or phenoxybenzamine. 2. The injection of serotonin into the ascending aorta produced an immediate rise in systemic, pulmonary arterial and pulmonary venous pressures and pulmonary venous resistance. After phenoxybenzmine, the rise in systemic and pulmonary arterial pressures remained unchanged, but previously observed increases in pulmonary venous pressure and resistance were blocked. In contrast, propranolol failed to abolish the rise in pulmonary venous resistance after serotonin injection into the ascending aorta. 3. These results confirm the observation that the vasoconstrictor effect attributed to intravenously injected serotonin on the arterial side of the pulmonary circulation is independent of the known sympathetic pathways. The data suggest that the pulmonary venoconstriction induced by intravenous serotonin is of reflex origin, abolished by alpha and beta receptor blockade, whereas the efferent arm of the reflex pulmonary venoconstriction following injection of serotonin into the ascending aorta is mediated via alpha-adrenergic receptors.

Animals