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Biomedical subjects

B P Udwadia

Publications and source records attributed to B P Udwadia.

8 recordsLinked to original sources
PubMed1978

The effect of tubocurarine and suxamethonium on directly and indirectly elicited contractions of skeletal muscle in unanaesthetized man using single and train of four impulses.

1 Contractions of adductor pollicis in unanaesthetized man were elicited by direct and indirect stimulation. Single twitch responses as well as those by a train of four impulses at 2 Hz for 2 s were elicited for indirect stimulation. 2 After a suitable control period, tubocurarine (0.05 mg/kg) or suxamethonium (0.08 mg/kg) was administered intravenously. 3 A stepwise diminution in the train of four impulses was noticed after tubocurarine. Indirectly elicited contractions due to single stimulus and direct muscle stimulation remained unaltered. 4 Partial blockade of transient duration occured after suxamethonium for single as well as train of four stimuli. Directly elicited contractions remained unchanged. The intensity of blockade depended on the rate of injection of suxamethonium. 5 Indirectly elicited contractions by train of four impulses is a reliable and sensitive method for testing neuromuscular blocking drugs in unanaesthetized man.

Adult↗
PubMed1975

Beta-adrenoceptors in the human dorsal hand vein, and the effects of propranolol and practolol on venous sensitivity to noradrenaline.

1 Infusion of isoprenaline into dorsal hand veins preconstricted with noradrenaline produced vasodilatation in four subjects out of five which was reversed by addition of propranolol. It is confirmed that beta-adrenoceptors are present in the hand veins of most subjects. 2 Addition of either propranolol or practolol to infusions of vasoconstrictor doses of noradrenaline potentiated the vasoconstriction in the hand vein. 3 After systemic administration of propranolol (0.3 mg/kg) or of practolol (1.0 mg/kg) intravenously, the sensitivity of the hand vein to the vasoconstrictor activity of noradrenaline was increased by 7.5 times and 2.9 times respectively. Significant reductions in hand skin temperature and resting pulse rate occurred after propranolol only. 4 It is suggested that this may be a useful method for the quantitative estimation of peripheral vascular beta-adrenoceptor blocking activity in man. At the doses used, significant beta-adrenoceptor blockade appears to occur at this site with practolol as well as propranolol.

Adult↗