title: Correlation between gallbladder size and release of cholecystokinin after oral magnesium sulfate in man.
abstract: In order to determine the effect of oral magnesium sulfate on gallbladder contraction and release of cholecystokinin (CCK) in man, magnesium sulfate (25 g in 100 ml distilled water) was given by mouth to five fasting adult male volunteers. Plasma samples were collected for measurement of CCK by a specific radioimmunoassay. Gallbladder volumes were determined from sonograms obtained from a phased-array real-time ultrasound scanner. Basal concentrations of CCK (82.2 +/- 10.1 pg/ml) increased significantly at 20 minutes after oral magnesium sulfate (113.8 +/- 7.1 pg/ml), and reached a maximal value at 50 minutes (150.0 +/- 42.0 pg/ml). The mean basal volume of the gallbladder was 30.8 +/- 5.3 cm(3) and maximum reduction of gallbladder volume (to one third of original) was achieved at 50 minutes after ingestion of magnesium sulfate. Linear regression analysis showed a close correlation (r = -0.9337) between plasma concentrations of CCK and gallbladder size in response to magnesium sulfate. Oral magnesium sulfate also caused a significant increase in serum gastrin (from basal of 51.4 +/- 9.9 pg/ml to 69.8 +/- 15.5 pg/ml at 5 min); there was no significant correlation between gastrin release and gallbladder contraction. This study provides direct evidence that the mechanism of magnesium sulfate-stimulated gallbladder contraction occurs through the release of CCK, and shows a close correlation between CCK release and contraction of the gallbladder.
mesh_terms: D000328:Adult; D002766:Cholecystokinin / Q000096:biosynthesis / Q000097:blood*; D005704:Gallbladder / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology; D005755:Gastrins / Q000097:blood; D006801:Humans; D008278:Magnesium Sulfate / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male
chemical_list: D005755:Gastrins; D008278:Magnesium Sulfate; D002766:Cholecystokinin