Abstract
The effect of commercial preparations of pectinase and pectinesterase on the distribution and intensity of periodic acid-Schiff reactions was investigated in tissues fixed in acetone, Bouin, Zenker-formol and Carnoy.
The periodic acid-Schiff staining of collagenous fibers in connective tissue, the lens, seminal vesicle secretion, and keratin from skin regardless of fixation was intensified after incubation of sections of these tissues with the enzyme preparations at 37°C. in 0.2 M acetate buffer for 6-48 hours. The intensification of these structures, which appeared to be independent of the type of fixation, was shown to be due to the adsorption of a carbohydrate component of the enzyme preparation supplying the additional 1,2-glycol groups which reacted with periodic acid-Schiff.
After acetone fixation only, the periodic acid-Schiff reactive material was removed from mucus, coagulating gland and prostate secretions, and was decreased in cartilage matrix and the brush border of kidney. These effects were attributed to a heat labile "mucinase" of unknown nature present in commercial pectinase which is active at an acid pH. The loss of staining of sublingual gland secretion noted after Zenker-formol fixation may also be attributed to this enzyme.