Effect of prostanoids on human intestinal Na-K-ATPase activity.
To elucidate whether prostanoids affect the activity of human intestinal Na-K-ATPase (an enzyme that has an important role in intestinal sodium and water absorption), basal human jejunal and colonic Na-K-ATPase activities were measured. In normal subjects, the mean (+/- SE) activities were 2.30 +/- 0.20 (n = 18) and 2.06 +/- 0.27 (n = 12) mumol/h . mg protein, respectively. Prostaglandin (PG) E2 (1.3 microM) induced significant inhibition of both the jejunal and the colonic enzyme activities: 82 +/- 5 and 50 +/- 8% inhibition, respectively. The inhibition of the colonic enzyme activity was apparent after 5 min of incubation and was linear in the first 20 min; it correlated with the amount of enzyme protein. PGD2, 6-keto-PGF1 alpha and thromboxane B2 did not affect either the jejunal or colonic Na-K-ATPase activities. These results indicate that PGE2 inhibits intestinal Na-K-ATPase activity. This inhibition may increase intestinal net fluid accumulation and thus may contribute to the diarrhea induced by several prostanoids.
D015121:6-Ketoprostaglandin F1 alpha / Q000502:physiology; D003106:Colon / Q000201:enzymology*; D015232:Dinoprostone; D006801:Humans; D007408:Intestinal Absorption; D007583:Jejunum / Q000201:enzymology*; D015230:Prostaglandin D2; D011457:Prostaglandins D / Q000502:physiology; D011458:Prostaglandins E / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013929:Thromboxane B2 / Q000502:physiology
D011457:Prostaglandins D; D011458:Prostaglandins E; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D000254:Sodium-Potassium-Exchanging ATPase; D015232:Dinoprostone; D015230:Prostaglandin D2