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Biomedical subjects

R F WHELAN

Publications and source records attributed to R F WHELAN.

At least 37 records · Page 2Linked to original sources
PubMed1959

Cardiovascular effects of intravenous infusions of 5-hydroxytryptamine in man.

Intravenous infusions of 5-hydroxytryptamine creatinine sulphate in doses of 1,2, and 3 mg./min. of the salt into 42 normal subjects caused a dilator response of the forearm vessels, consisting of an initial transient increase in flow usually followed by a smaller but sustained increase. A fall in forearm flow was not seen. Heart rate was invariably increased and the increase preceded other changes by 10 to 20 sec. suggesting a direct effect on the heart. The sustained increase in flow probably represents a balance between the direct constrictor action of the drug and a secondary dilator effect. The blood pressure response was variable and it appeared unlikely that it was responsible for more than a small part of the forearm flow changes. Two subjects appeared to be abnormally sensitive to the drug.

Cardiovascular System↗
PubMed1957

The effect of inhalation of 30% carbon dioxide on the peripheral circulation of the human subject.

Inhalation of 30% carbon dioxide for 1 to 2 min. caused a transient increase followed by a marked fall in blood flow through the normal forearm and calf. Since there was an associated large increase in arterial blood pressure, the fall in flow was due to intense vasoconstriction. It is likely that the vasoconstriction in the forearm occurred deep to the skin because the oxygen saturation of the superficial venous blood did not fall during the inhalation. Since there was a slight decrease in flow through the nerve-blocked forearm in spite of the increased blood pressure, it is unlikely that nervous vasoconstriction can completely account for the marked decrease in muscle flow.

Blood Circulation↗
PubMed1957

The antagonism of the vascular effects of 5-hydroxytryptamine by BOL 148 and sodium salicylate in the human subject.

2-Bromo-(+)-lysergic acid diethylamide (BOL 148) is a specific antagonist of the constrictor response of the forearm and hand blood vessels to intra-arterial infusions of 5-hydroxytryptamine. This has been shown to be a direct action in the tissue concerned, since the antagonism was as effective when the drug was given by local arterial injection as when given intravenously. Sodium salicylate is also a specific antagonist of 5-hydroxytryptamine, but its action is indirect, occurring only when the general serum level was raised above 10 or 20 mg.%; local limb concentrations of 30 to 40 mg.% had no antagonistic effect. The mechanism of the antagonistic effect of salicylate is not known. It is not related to the associated hyperventilation but is possibly due to the secondary release of, or synergism with, some other substance, probably a hormone.

Blood Vessels↗