Mechanism of production of intestinal secretion by negative luminal pressure
Hakim, A.A.; Papeleux, C.B.; Lane, J.B.; Lifson, N.; Yablonski, M.E.
American Journal of Physiology 233(5): E416-E421
1977
ISSN/ISBN: 0002-9513 PMID: 920804 Document Number: 114276
After dogs weighing 15 to 35 kg had been deprived of food for 16 to 24 h, a section of upper jejunum about 15 cm long supplied by an artery was inserted in a Wells clamp modified in that a thermistor probe protruded into the centre of the clamp chamber so that it was maintained at 37 deg C. The relations between luminal hydrostatic pressure and fluid transport were compared with quantitative predictions from a model proposed for the mechanism of the secretion produced by increased venous pressure. According to the model, the secretion produced by increasing venous pressure and the secretion produced by negative luminal pressure are both passive filtrates contingent on a transepithelial pressure of a few cm water. The observations showed a predicted gross asymmetry in rates of fluid transfer with isotonic fluids depending on whether the luminal pressure was positive or negative, the observed magnitude of the negative luminal pressure required for the onset of secretion agreed with predictions and the secretion contained significant amounts of protein at about 25% of the plasma concentration.