[The kinetics of canine gallbladder before and after feeding and cerulein administration]

In the previous studies in men and dogs, gallbladder contractility, contraction time, initial and residual volumes as well as ejection and refilling fractions have been determined. However, no basic scope of the characteristics of contractile gallbladder activity has been determined and no parameters measured in basic experimental conditions, necessary for this purpose, have been proposed what was the aim of present work. Twenty two experiments were performed on four healthy mongrel dogs weighing 12-16 kg each. Dogs were fasted 18-20 h before start of the experiment. Animals were examined in lying position with the use of apparatus Microimager 2000 M 200 812 with sectorial sound, 3.5 MHz. After control gallbladder measurements, animals were fed with different meals or 30 min infusion of cerulein at the dose 20 ng/kg was started. Four types of meals were used. Meal 1: dry food 300 g + 200 cc of tap water per animal. Meal 2: canned food 300 g + 200 cc of tap water per animal. Meal 3: dry food 100 g + + canned food 200 g + sunflower oil 100 ml per animal. Meal 4: dry food 300 g + canned food 300 g + sunflower oil 30 ml per animal. Ultrasonographical gallbladder imaging was performed in each experiment every 10 min and was continued during 2 hours after stimulus application. Length, width and height of the gallbladder was measured on gallbladder images, then gallbladder volumes were estimated using the method of Dodds and finally, gallbladder kinetic parameters were calculated. Meals 1 and 2 did not evoke statistically significant gallbladder contractions. After meal no. 3 gallbladder significantly contracted, for about 1.5 h. Meal no. 4 caused gallbladder contraction duration of which exceeded time of investigation while maximal strength of contraction was similar to that in response to meal no. 3. Following cerulein infusion, subsequent parameters of gallbladder kinetics, i.e. initial, residual and terminal volumes, ejection and refilling fractions as well as contraction time were similar to those after meal no. 3 while gallbladder refilling time was significantly longer than after meal no. 3.