The measurement of histochemically-stained NADP-dependent isocitrate dehydrogenase in the sebaceous glands of hairless hamster.

The effect of substrate, co-factor and Nitroblue Tetrazolium concentration on the production of formazan by the action of NADP-dependent isocitrate dehydrogenase was studied in the sebaceous glands of the hairless hamster. The measurement (in average optical density units per unit area) of formazan in histochemically stained skin sections was carried out by television scanning microdensitometry (Quantimet 720D). Having established optimal conditions for this enzyme, a second study was carried out to determine the effect of different power objectives and wide-band wavelength light instead of white light on the average optical density per unit area, recorded by the instrument, of the formazan produced in a defined number of sebaceous glands in a single skin section. It was found that there was no difference in the average optical density per unit area recorded by the instrument at different power objectives and a peak value of average optical density per unit area could be obtained using a K4 or a K5 Balzer filter (550-650 nm).