Aminopeptidases of mechanically strained and normal rat gingiva, with special reference to aminopeptidase B

Abstract

Abstract

Aminopeptidase activity of normal and mechanically strained rat gingiva was studied using various N-L-aminoacyl-2-naphthylamine derivatives as substrates. Mechanical occlusal strain was directed to the first and second molar. The healing was studied 1, 3, 8 and 12 hours after the treatment. The mechanical treatment caused the disappearance of a gingival aminopeptidase which was inhibited by 0.2 M NaCl. This enzyme reappeared in the eight hour samples. All tissue samples (of the strained and control tissue) contained an enzyme so closely related to the rat liver aminopeptidase B (APB) that the presence of a true APB in rat gingiva was considered to be very likely. The activity of APB increased during the first hours, but this took place almost equally in both control and strained tissue, an indication that the strong mechanical treatment had also affected the control tissue of the test animals. The mechanical treatment used led to disturbances in the content of the studied enzymes in gingiva. The healing of the tissue, however, restored the initial situation within eight or twelve hours.