Ion channel block in rat diaphragm by the venom of the digger wasp Philanthus triangulum.
In the rat phrenic nerve-diaphragm preparation the twitch tension and tetanic contractions, already reduced by d-tubocurarine, succinylchloride or neostigmine, are further reduced by the venom of the digger wasp Philanthus triangulum F. The venom reduces the temperature- and voltage-sensitivity of the acetylcholine-receptor-activated ion channels, at the motor end-plate, and shortens the decay time of the miniature end-plate currents, analogous to a block described for the purified toxin, delta-PTX, on insect glutamate-activated channels. Preliminary results show that delta-PTX has an effect similar to that of the total venom on the decay phase of miniature end-plate currents.
D000109:Acetylcholine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001514:Bee Venoms / Q000494:pharmacology*; D003964:Diaphragm / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects*; D009045:Motor Endplate / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000378:metabolism*; D011073:Polyamines; D051381:Rats; D013696:Temperature; D014403:Tubocurarine / Q000494:pharmacology; D014862:Wasp Venoms / Q000494:pharmacology*
D001514:Bee Venoms; D007473:Ion Channels; D011073:Polyamines; D014862:Wasp Venoms; C034092:delta-philanthotoxin; D000109:Acetylcholine; D014403:Tubocurarine