Premium
OBSERVATIONS ON THE ELIMINATION RATES OF SINGLE INJECTIONS OF TAUROCHOLATE AND CHOLATE IN THE DOG
Author(s) -
O'Máille E. R. L.,
Richards T. G.,
Short A. H.
Publication year - 1969
Publication title -
quarterly journal of experimental physiology and cognate medical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0033-5541
DOI - 10.1113/expphysiol.1969.sp002028
Subject(s) - taurine , chemistry , sodium cholate , excretion , bile duct , bile acid , medicine , endocrinology , chromatography , biochemistry , amino acid
Single intravenous injections of taurocholate were eliminated in the bile more rapidly than those of cholate in the anæsthetized dog in which the common bile duct had been cannulated. The time taken for the first 50 per cent of the total biliary excretion (T 50 per cent ex.) was measured. For taurocholate it was 12·7 ± 1·2 (S.D.) min and for cholate 18·9 ± 1·8 min. About four‐fifths of injected cholate appeared in bile conjugated as taurocholate, the remainder as free cholate. Each bile salt was given as a dose of 0·12 m‐mole/kg body wt; at twice this dosage the mean T 50 per cent ex. for taurocholate was 14·2 min and for cholate was 25·5 min. Taurocholate was also eliminated more rapidly than glycocholate. The delay in excretion of cholate is probably due to (a) the extra time necessary for its conjugation with taurine in the liver before excretion, (b) the extra time required for the transfer of the remainder of the dose as free cholate, whose excretion is less efficient than that of taurocholate, and (c) the fact that cholate appears to gain entry to a wider distribution space than taurocholate, and hence proportionately less is presented to the liver in unit time for removal. After the first 5‐10 min from completion of the injection the disappearance of taurocholate from plasma was also more rapid than that of cholate. The fraction of bile salt removed in a single passage through the liver, determined at 5 min intervals after injection, was lowest for the first 5 min calculation and thereafter progressively increased. The extraction fraction for cholate was always less than that for tauro‐ and glycocholate; for the latter two it reached a value of over 95 per cent by 15‐20 min.