IN-VITRO CONTRACTILITY PATTERN OF MUSCLE STRIPES FROM STONE FREE AND STONE DISEASED GALLBLADDERS - RELEVANCE OF THE PROSTAGLANDIN SYSTEM FOR THE CCK-REGULATED MOTILITY

This study discribes the influence of endogenous and exogenous prostag landines upon CCK-induced motility patterns of human gallbladders with and without stones (indomethacin and nocloprost; an exogenous PGE2-an alogon). From 48 gallbladders with - and 22 gallbladders without stone s (control group) longitudinal muscle stripes were dissected and trans ferrred to an organ bath and CCK, indomethacin and nocloprost dose res ponse curves were established. In another experimental protocol, the e ffect of CCK after indomethacin or nocloprost preincubation is demonst rated. Moreover, specimens of gallbladders were taken for histology an d gallstones for analyse. The results demonstrate that gallbladders wi th stones have a significant higher basic tonus and phasic acitivities compared to the stone-free controls. Because of these different respo nses to CCK, gallbladders of the stone-diseased group were divided in two groups: 64% of the gallbladders show a sensitivity and tonic respo nse to CCK like the controls (contractors), 36% demonstrate a reduced sensitivity to CCK and only a slight tonic response (non-contractors). Indomethacin causes a fall in tonus in both stone-diseased groups. It stops spontaneous acitivity in the contractor and non-contractor grou p. With indomethacin preincubation all three groups response to CCK wi th a significant reduced sensitivity. CCK-induced activity is reduced in the control and contractor group. In the non-contractor group, musc le strips do not contract after indomethacin preincubation. Nocloprost induces significant contractions in the control and contractor group. In both groups, the response to CCK after nocloprost preincubation is stronger than the reaction without preincubation. In the non-contract or group, a change in tonus after nocloprost application cannot be dem onstrated, there also is no response to CCK after nocloprost preincuba tion. These results corroborate the notion of a significant contributi on of the endogenous prostaglandin system to the regulation of gallbla dder motility by CCK.