Entry of decamethonium in rat muscle studied by autoradiography.
1. When a steady plasma level of decamethonium was maintained by infusion in rats, the labelled compound became concentrated in the region of the end-plate of skeletal muscle, as shown by scintillation counting.2. The distribution of tritium-labelled decamethonium in single muscle fibres was studied by autoradiography of frozen sections, with resolution less than 1 mu.3. After intravenous injection of a dose of decamethonium which produced partial paralysis it was shown that the labelled compound had entered muscle fibres in the region of the end-plate, and for several hundred microns on either side of the end-plate.4. Entry of decamethonium could be demonstrated as early as 30 sec after intra-arterial injection. There was no evidence of any redistribution of labelled drug for a period of 2 hr after the initial entry.5. Previous administration of tubocurarine markedly reduced the entry of labelled decamethonium.
D000818:Animals; D001345:Autoradiography; D003650:Decamethonium Compounds / Q000097:blood / Q000378:metabolism*; D003964:Diaphragm / Q000378:metabolism; D005615:Freezing; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D007700:Kinetics; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D013997:Time Factors; D014316:Tritium; D014403:Tubocurarine / Q000494:pharmacology
D003650:Decamethonium Compounds; D014316:Tritium; D014403:Tubocurarine