IMPAIRED CONNECTIVE-TISSUE REPAIR IN STREPTOZOTOCIN-INDUCED DIABETES SHOWS ULTRASTRUCTURAL SIGNS OF IMPAIRED CONTRACTION

Streptozotocin-induced diabetes mellitus is known to impair connective tissue repair in the perforated rat mesentery. The aim of the present investigation was to study quantitatively by morphometrical technique s the influence of diabetes on some aspects of the cellular ultrastruc ture related to connective tissue contraction in such healing. The cel lular volume density increased significantly with time, presumably as a consequence of disappearance of interstitial edema. No difference wa s found in the amount of healing tissue formed between controls and di abetics. The surface volume density of the plasma membrane was signifi cantly higher in control animals on Days 1-10, indicating an increased number of cellular protrusions and spikes which relate to the motilit y of the cells. The volume density of contractile filaments did not di ffer between controls and diabetics. The results suggest a reduced sur face density of plasma membrane in diabetic cells, a finding which is compatible with reduced wound contraction in diabetes. (C) 1995 Academ ic Press, Inc.