A quantitative analysis of perineurial cell basement membrane collagen IV, laminin and fibronectin in diabetic and non-diabetic human sural nerve

Abstract

The thickness of the perineurial cell basement membrane was examined in diabetic and non-diabetic human sural nerve. A significant increase in thickness was found in the diabetic group. The nature of this thickening was investigated using immunohistochemistry and image analysis in order to semi-quantify three of the major intrinsic components of the perineurial cell basement membrane: collagen IV, laminin and fibronectin. Amounts of all three components were shown to be increased in the diabetic group, but not significantly so. However, significant linear correlations between fascicle size and perineurial collagen IV, laminin and fibronectin were identified in both diabetic and non-diabetic nerve.

Fig. 1

Part of the perineurium of a human sural nerve. Each perineurial cell (PC) is bordered on both surfaces by basement membrane (BM). Between each perineurial cell layer are collagen fibrils (CF). Scale bar = 1 μm.

Fig. 2

Part of an electron micrograph montage of the perineurium from which basement membrane thickness measurements were made. Measurements were taken at 2-cm intervals along the length of each perineurial cell basement membrane (arrow). Scale bar = 1 μm.

Fig. 3

A single human nerve fascicle thresholded for assessment of perineurial collagen IV content, endoneurium (EN), perineurium (P). Highlighted pixels representing collagen IV found elsewhere in the nerve structure have been excluded. (×100).

Fig. 4

A paraffin wax section of a human sural nerve immunostained for collagen IV. The perineurium (P) shows deep staining. Complete nerve fascicles (NF) were easily visualized with the image analyser using a low-power objective (×100).