A sensitive analytical apparatus for measuring hydrogen production rates. I. Application to studies in small animals. Evidence of the effects of an α-glucosidehydrolase inhibitor in the rat

A gas analysis and sampling methodology is described for determining total hydrogen excretion rates in Wistar rats. Hydrogen concentrations are evaluated by gas chromatography, using a molecular sieve column connected to a reduction gas detector. Resolution of the analysis is 0.015 ppm hydrogen in a 2.5-ml sample which is 50–100 times more sensitive than previous techniques. Gas samples are obtained by a single-pass (as opposed to rebreathing) method in which hydrogen-free air is passed through glass cylinders containing the experimental animals. Mixing of the animal's excreted hydrogen with the chamber flow results in increased hydrogen concentrations at the chamber outlet, from which each animal's endogenous production rate can be determined. The method is completely automated and enables multiple studies to be performed simultaneously. As an assessment of the capability of the system to detecting variations in hydrogen production due to carbodydrate malabsorption, 5 male Wistar rats received feeding of both sucrose alone and sucrose plus a known α-glucosidehydrolase inhibitor. In this manner, each animal served as its own control in evaluating the effect of the inhibitor. Administration of sucrose alone resulted in a mean increase in hydrogen production rate of 39% over a 7-h time period, following the initial rise in hydrogen concentration from baseline levels. Administration of sucrose plus inhibitor caused corresponding increases of 95%. Because of the sensitivity and simplicity of the method, it is expected to be a valuable aid in continuing studies of carbohydrate malabsorption of various etiologies.