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M W SMITH

Publications and source records attributed to M W SMITH.

14 recordsLinked to original sources
PubMed1964

SOME PHARMACOLOGICAL PROPERTIES OF URIDINE NUCLEOTIDES.

Uridine di-, tri- and monophosphates (UDP, UTP and UMP) contracted the goldfish intestine preparation in that order of decreasing potency. Adenosine triphosphate (ATP) sensitized the gut to UTP and UDP but not to UMP. The fluoro-derivatives of UMP and UTP behaved like the unsubstituted nucleotides on the goldfish intestine but the main effect of 6-azaUDP and large amounts of uracil and uridine was to cause a relaxation. Structure-action relationships are discussed on the basis of these findings. UDPglucose and UDPacetylglucosamine each contracted the goldfish intestine but they were 500-times less active than UDP. Other smooth muscle preparations (tortoise jejunum, rat uterus, guinea-pig ileum and the fowl rectal caecum) contracted to UTP and UDP, but large amounts were needed. The cardiovascular effects in rats of UMP, UDP and UTP were complex and mediated mainly through an action on the peripheral blood vessels. In rats treated with phenoxybenzamine, UMP raised the blood pressure while UDP and UTP first lowered then raised the blood pressure. The fall in blood pressure was not abolished by pronethalol or atropine. The uridine phosphates affected the rat isolated heart only under hypoxic conditions. UTP and UDP dilated the blood vessels of the rabbit ear and UTP was six-times more effective than ATP. UTP and UDP were equiactive in increasing the force of beat of the frog isolated heart. UMP also had an effect if large amounts were given.

Adenosine Triphosphate↗
PubMed1959

The fate of oxytocin in male and female rats.

A method for quantitative extraction of oxytocin from blood is described. The disappearance of injected oxytocin from the circulation in rats was shown to depend upon its uptake in the kidneys and in organs of the splanchnic vascular area. In lactating rats there was uptake by an additional organ or tissue, probably the mammary gland. In animals without kidneys or lactating mammary glands and with no circulation in the splanchnic area oxytocin was distributed into a volume greater than the extracellular fluid volume, and after equilibration the concentration in plasma did not change significantly. During severe haemorrhage increased amounts of antidiuretic activity were detected in blood when there was no significant increase in oxytocic activity.

Animals↗
PubMed1954

NSNA's first year.

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Education, Nursing↗