IN-VITRO EFFECTS OF CHOLECYSTOKININ FRAGMENTS ON HUMAN GALLBLADDERS -EVIDENCE FOR AN ALTERED CCK-RECEPTOR STRUCTURE IN A SUBGROUP OF PATIENTS WITH GALLSTONES

Background/Aim: This study addresses cholecystokinin (CCK)-receptor al terations in stone-diseased and stone-free human gallbladders using di fferent CCK-fragments. Methods: Serosa-free muscle strips were mounted in a modified Krebs-Henseleit-solution of 37 degrees C and aerated wi th carbogen, The following concentrations of CCK-fragments (CCK 26-33, N-Acetyl CCK 27-33 sulf., CCK 26-29 sulf., CCK 25-33 sulf.) were achi eved: 0.1 nmol, 0.5 nmol, 2 nmol, 10 nmol, 100 nmol. Results: Stone-di seased gallbladders were classified into two groups based on their in vitro reaction to CCK 26-33 (CCK-octapeptide). Muscle strips not contr acting below 10 nmol were assigned to the subcontractor group, Histolo gically scarification, necrosis and signs of severe inflammation of th e mucosa were seen in 76.9% of this group. Those starting contractions at 0.1 nmol (like the control group) were called the contractor group . This group had a shallow mucosa and mild inflammatory signs in 54.5% , The sub-contractor group showed higher spontaneous phasic activity a t lower tonic activity than the contractor and control groups, In the sub-contractor group CCK 27-33 caused several times higher contraction s than all other fragments, A maximal contraction level in the contrac tor and control groups was reached by CCK 25-33. Conclusion: This stri king effect of CCK 27-33 in the sub-contractor group favors the view o f CCK-receptor structural alteration in a subgroup of patients with ch olecystolithiasis.