Inhibition of electrogenic sodium transport across toad urinary bladder by the mycotoxin patulin.
The effects of the mycotoxin patulin (4-hydroxy-4H-furo[3,2c]pyran-2(6H)-one) on short circuited intact toad bladder and on Na+-K+, activated ATPase were examined in an attempt to elucidate the relationship between toxin, the Na+-K+ ATPase enzyme system and associated active sodium transport. Patulin inhibited transbladder short circuit current and Na+-K+ ATPase from isolated bladder preprations. The effect was exponentially dependent on time. A significantly slower rate of inhibition was achieved within 15-30 min. The results are compatible with the assumption that Na+-K+ ATPase is associated with the pump mechanism since patulin inhibited enzyme activity and concomitantly reduced the rate of electrogenic Na+ transport. A significant correlation suggested a cause-effect relationship.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002024:Bufo marinus; D002463:Cell Membrane Permeability / Q000187:drug effects; D010365:Patulin / Q000494:pharmacology*; D011714:Pyrans / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013997:Time Factors; D001743:Urinary Bladder / Q000201:enzymology / Q000378:metabolism*
D011714:Pyrans; D010365:Patulin; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase