The effect of glucocorticosteroids on in vitro motility of the ureter of the sheep

1 The effects of three glucocorticosteroids, hydrocortisone, methylprednisolone and dexamethasone, as well as two non‐steroidal anti‐inflammatory agents (NSAIDs) indomethacin and diclofenac sodium were tested in vitro on the spontaneously rhythmic contracting ureteral preparation of the sheep. 2 The NSAIDs and the steroids methylprednisolone (10−7‐10−4m) and dexamethasone (10−8‐10−4m), dose‐dependently inhibited ureteral motility. Hydrocortisone caused a cessation of spontaneous contractions only at the high concentration of 10−4 m. 3 Pretreatment of ureteral strips with the protein synthesis inhibitor cycloheximide (10−6m) abolished the inhibitory action of the corticosteroids on peristalsis, consistent with the suggestion that the action of steroids on the ureter is mediated via the synthesis of the anti‐phospholipase protein, lipocortin. 4 The potency of the steroids in descending order was found to be dexamethasone > methylprednisolone > hydrocortisone.