Jejunum is more important than terminal ileum for taurocholate absorption in rats
| Autor: | C. McClintock, Y. F. Shiau |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Male
Taurocholic Acid medicine.medical_specialty Physiology Ileum digestive system Jejunum Bolus (medicine) In vivo Physiology (medical) Internal medicine Distal ileum medicine Terminal ileum Animals Intestinal Mucosa Enterohepatic circulation Hepatology Chemistry digestive oral and skin physiology Gastroenterology Biological Transport Rats Inbred Strains Rats Kinetics medicine.anatomical_structure Endocrinology Intestinal Absorption Biochemistry Organ Specificity Transport system |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 244:G507-G514 |
| ISSN: | 1522-1547 0193-1857 |
| DOI: | 10.1152/ajpgi.1983.244.5.g507 |
| Popis: | The terminal ileum, with its active transport system, is considered the major site of bile salt absorption. However, earlier studies used bile salt concentrations below physiological levels and may not apply in vivo. Analysis of these studies shows that ileal active transport cannot account for total bile salt recovery. To reevaluate bile salt absorption in rats, we used four preparations and physiological bile salt concentrations. Studies with intestinal sacs showed that, above critical micellar concentration, uptake of taurocholate (TC) was equal in both jejunum and ileum and linear with respect to concentration. A similar pattern was observed in studies of mucosal-to-serosal TC transport using a flux chamber. In vivo studies in anesthetized rats showed approximately 30% of TC absorbed from proximal jejunum and appearing in bile when the bolus had traversed only half the intestine. In unanesthetized fed rats, 60% of TC appeared in bile before the bolus reached distal ileum. Because luminal concentrations of TC are highest proximally, passive absorption by the proximal intestine is mainly responsible for conserving TC within the enterohepatic circulation. Ileal active transport is more efficient at low concentrations and absorbs the TC remaining after proximal absorption. |
| Databáze: | OpenAIRE |
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