Water and chloride exchange across the gall bladder of the anesthetized dog

¹ Department of Physiology, Yonsei University, College of Medicine, Seoul, Korea

The gall bladder was cannulated in the anesthetized dog and various solutions were introduced into it, in order to study the exchange characteristics of the gall bladder wall to water, as well as to various solutes. The gall bladder wall was highly permeable to urea and less to NaCl while it was not to sucrose. When various sucrose solutions were introduced, the fluid volume within the gall bladder varied as a function of the existing osmotic pressure gradient, indicating that the gall bladder under some conditions resembles an osmometer. The gall bladder wall was able to absorb chloride against a tenfold concentration gradient. However, this ability to absorb chloride was abolished in presence of 10^–2 m monoiodoacetic acid, but not in presence of 2,4-DNP, NaF, or KCN, suggesting that the chloride absorption is carried out by glycolytic energy. Since the gall bladder bile, as well as the hepatic bile, was isosmotic with plasma, it is concluded that the primary event of concentrating bile within the gall bladder is the active absorption of NaCl accompanied by water.