A study on the buffering activity of the human rectum. In vivo demonstration of HCO3- and H+ secretion after rectal application of fluids with an unphysiological pH.
The buffering activity of the human rectum was evaluated in various pilot studies, using a rectal lumen perfusion method. Quantitative alkaline and acid secretion was measured, respectively, by direct titration according to the pH-stat method. The change in composition of the perfusate with regard to the test drug benzoate and the concentration HCO3- was detected. The pilot studies suggest that rectal mucosa is capable of neutralizing a pH deviating from the physiological value within a remarkably short time. In the acid region, at least a part of the alkalizing activity is the result of HCO3- secretion. It has been shown that this process is stimulated by the H+ as well as Cl- ions. In the basic region neutralization very likely occurs by means of H+ secretion.
Böttger
W M
WM
St. Maartens Hospital, Venlo, The Netherlands.
Schoonen
B J
BJ
Moolenaar
F
F
Visser
J
J
Meijer
D K
DK
D001639:Bicarbonates / Q000378:metabolism*; D002021:Buffers; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011522:Protons; D012007:Rectum / Q000378:metabolism*
D001639:Bicarbonates; D002021:Buffers; D011522:Protons