[The contraction of intestinal myocells and block of cationic pumps].
The effects of a block of Na-K-ATPase pump on the contraction of intestinal smooth muscle (ileum of guinea pig) induced by carbachol has been analysed. Two parameters have been evaluated: a) maximum velocity of contraction (Vmax.C); b) maximum velocity of relaxation (Vmax.D) after washing. The block of pump is produced by a digitalic agent (desacetyl-lanatoside C). The application of 0.3 micrograms/ml of lanatoside for 1 min causes an increase of Vmax.C and a decrease of Vmax.D; whereas it does not influence the height of contraction. This effect is in agreement with the mechanism of action of Na on the contraction curve.
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D003892:Deslanoside / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects*; D007700:Kinetics; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000187:drug effects*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D002217:Carbachol; D000254:Sodium-Potassium-Exchanging ATPase; D003892:Deslanoside
Contrazione delle miocellule intestinali e blocco delle pompe dei cationi.