SIMULTANEOUS ASSESSMENT OF GALLBLADDER EMPTYING IN THE DOG BY REAL-TIME ULTRASONOGRAPHY AND STRAIN-GAUGE

Patterns of meal- and cerulein-induced gallbladder emptying (GEE) were compared in four dogs equipped with a force transducer implanted onto the body of the gallbladder, and in four unoperated animals. GEE was examined by real-time ultrasonography in conscious dogs. In two dogs t he ultrasonographic measurement of GEE was performed simultaneously wi th the registration of the strain exerted on the force transducer fixe d on the gallbladder body. Implantation of the force transducer onto t he gallbladder impaired neither postprandial nor cerulein-induced GEE. The contractile response of the gallbladder exhibited a nonlinear rel ationship to the gallbladder volume. The reduction of gallbladder volu me to 50% of its basal value was accompanied by an increase in strain amounting to about 16% of the maximum response, whereas a pronounced a ugmentation of the strain was observed with gallbladder volume ranging between 30% and 10% of the basal value. On the other hand, the contra ctile response of the gallbladder registered by means of a force trans ducer was linearly related to the angle ct contained between two radii passing from the gallbladder center towards the edges of the strain g auge: y = 0.852 alpha - 30.97 (r = 0.959, P < 0.001) in the case of i. v. cerulein infusion at stepwisely increasing doses (0.7-2.2-7.4-22.2- 66.5 pmol . kg(-1)h(-1)), and y = 0.640 alpha - 17.40 (r = 0.869, P < 0.001) for a 1-h constant-rate 22.2 pmol . kg(-1) h(-1) cerulein infus ion.