Quantification of α-glucosidases along the villus of the small intestine in man

Abstract

A method is introduced which enables the two-dimensional detection and analysis of absorbancy-values from continuous dye-deposites with rather low data storage capacity. Applied to histochemical reactions this method is used for kinetic analysis of enzymes along the intestinal villus. Its main part consists of two programs for two dimensional scanning, i.e. along the villus and at right angle from the lumen across the brush-border membrane to the apical cytoplasma. Two further programs serve as prerequisites: the automatical detection of mean values and the description of absorbancy spectra in the tissue section. The measurements are carried out with a MPVII Leitz in connection with a Hewlett Packard 9815 A calculator. The study of alpha-glucosidases of the human small intestine is taken to demonstrate the value of the method. It is shown that a similar Vmax-gradient along the villus can be demonstrated as by microchemical methods. Thus this method enables the description of the kinetic properties of a distinct enzymatic activity in preserved tissue sections on the cellular level and the possible alterations of Vmax and Km in context to the morphological pattern.