Application of high performance liquid chromatography to study transport and metabolism of nucleic acid derivatives by rat jejunum in vitro: endogenous washout.

A procedure is described for maintaining segments of rat jejunum in vitro in a steady state of fluid and solute absorption for periods of up to 2 h so that the secretion of endogenous and exogenous nucleic acid derivatives across the serosa may be followed. Methods of high performance liquid chromatography for the separation and measurement of some nucleic acid derivatives are also described. These procedures are applied to investigate three endogenous components found in the washout into the serosal secretions. The kinetics of the washout are, in each case, mono-exponential and the effects of pre-feeding, of pre-feeding a glucose solution and of the diabetic state on the washouts have been investigated. One of the components of the washout is uric acid, the initial pool size of which varies from 13-22 mumol/g dry wt. of jejunum. Negligible amounts of derivatives of endogenous origin appear in the lumen.