Effect of long-acting somatostatin analogue (octreotide, SMS 201-995) plus calcium channel blocker (verapamil) on gallbladder contraction.

BACKGROUND/AIMS: In this study we investigated the effect of the long-acting somatostatin analog octreotide (SMS 201-995) plus calcium channel blocker (Verapamil) on gallbladder contraction.

METHODOLOGY

Fourty healthy volunteers participated in this study. Gallbladder volumes were measured by ultrasonography. After recording the baseline measurement, the volunteers received either saline (n:10), or SMS 201-995 100 B microgram subcutaneously (s.c.) (n:10) or verapamil 80 mg peroral (po) (n:10), or verapamil plus SMS 201-995 (n:10). Two hours later the gallbladder volumes were rescanned in 15 min intervals for 60 min. At the end all volunteers received standard liquid test meal (ensure 250 Cal/250 ml) and scans were again performed for one hour.

RESULTS

The mean baseline gallbladder volume was 18.6 +/- 5.2 ml in all groups. The gallbladder volumes in the placebo group were 18.6 +/- 5.2 to 19.0 +/- 10.2 ml. In this group, after administration of test meal decreased the mean gallbladder volume to 14.3 +/- 7.5 to 8.4 +/- 5.8 ml, but these values were not significantly different from the baseline values. In the verapamil group the volumes increased from 18.6 +/- 5.2 to 28.5 +/- 9.7 to 30.8 +/- 11.6 ml. These values were significantly different from the baseline and the control group (p < 0.05). In this group, post-prandial mean volumes decreased to baseline in 30 min, but these values were higher than in the placebo group (p < 0.01). Verapamil-induced fasting the gallbladder relaxation was totally abolished to the placebo value by SMS 201-995. In verapamil plus SMS 201-995 and SMS 201-995 alone groups, the fasting and post-prandial volumes did not change when compared to the baseline value, but post-prandial volumes were higher than the placebo (p < 0.01).

CONCLUSION

These results suggest that verapamil-induced gallbladder relaxation was totally abolished by SMS 201-995.