title: Ion transport by the pig colon: effects of time and anesthesia.
abstract: A method for temporarily isolating a 50-cm loop of ascending spiral colon in the pig allowed a study of the effect of halothane anesthesia on colonic absorption without complications of acute surgical trauma, and provided a means to obtain timed samples of the colonic solution. Test solutions instilled into the loop consisted of a volatile fatty acid solution, similar in composition to normal colonic contents, and a Ringer solution. Ther was no apppreciable change in the rate of net solute absorption in conscious or anesthetized animals in repeated 1-hour determinations over a 6-hour period, provided the cardiovascular and arterial acid base variables remained stable. Net rates and direction of individually transported solutes and H20 were essentially unaffected by anesthesia during 2-hour experimental periods. However, net solute changes in this closed-loop system were not constant during individual absorption periods. These changes were due to a volume dependence on the rate of net absorption and a rapid dissipation of the driving forces initially present. Failure to recognize these time-dependent changes may leas to serious misinterpretations of the results.
mesh_terms: D000769:Anesthesia, Inhalation / Q000662:veterinary*; D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D003106:Colon / Q000378:metabolism*; D004573:Electrolytes / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000378:metabolism; D006221:Halothane / Q000494:pharmacology; D007408:Intestinal Absorption / Q000187:drug effects; D009994:Osmolar Concentration; D010100:Oxygen / Q000097:blood; D012964:Sodium / Q000378:metabolism; D013552:Swine / Q000378:metabolism*; D013997:Time Factors; D014867:Water / Q000378:metabolism
chemical_list: D001639:Bicarbonates; D004573:Electrolytes; D005232:Fatty Acids, Volatile; D014867:Water; D002245:Carbon Dioxide; D012964:Sodium; D010100:Oxygen; D006221:Halothane