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Biomedical subjects

J R PARRATT

Publications and source records attributed to J R PARRATT.

At least 19 recordsLinked to original sources
PubMed1964

A COMPARISON OF THE EFFECTS OF THE PLASMA KININS, BRADYKININ AND KALLIDIN, ON MYOCARDIAL BLOOD FLOW AND METABOLISM.

Using a heated thermocouple technique it was shown that the plasma kinins, kallidin (lys-bradykinin) and bradykinin, increased myocardial blood flow, when given either by single injection or by continuous slow infusion, in the rabbit, cat, dog, monkey and chimpanzee. In every experiment systemic arterial blood pressure and myocardial vascular resistance fell by an amount related to the log of the dose of the kinin administered. These effects were seen with quite small doses of bradykinin and kallidin and demonstrate that the myocardial vascular bed is very sensitive to these plasma kinins. In larger doses, bradykinin increased "corrected temperature" -the myocardial temperature change corrected for alterations in blood flow and with heat losses controlled. This response represents a stimulation of metabolic heat production which was not observed with kallidin.

Animals↗
PubMed1958

Inhibition by various substances of oedema formation in the bind-paw of the rat induced by 5-hydroxytryptamine, histamine, dextran, egg-white and compound 48/80.

Of the substances studied for their inhibitory action of the oedema formation in the hind-paw of the rat, the most active was a new derivative of phenothiazine, related to chlorpromazine. It is methotrimeprazine {10-(3-dimethylamino-2-methylpropyl)-2-methoxyphenothiazine; 7044 RP}. This substance possesses potent antihistamine and anti-5-hydroxytryptamine properties, and doses of 0.25 mg./kg. inhibited the blueing and swelling of the foot after injections of histamine, 5-hydroxytryptamine, eggwhite, dextran or compound 48/80 into the feet of rats with sulphan blue (Evan's blue) dye in their circulation. The results indicate that both histamine and 5-hydroxytryptamine play rôles in increasing capillary permeability in the rat.

Animals↗