Investigation on the effects of experimental STZ-induced diabetic rat model on basal membrane structures and gap junctions of skin

摘要

This study was designed to determine the impairment of the skin structure in experimentally-induced diabetes with injection of streptozotocin (STZ). Experimental groups consisted of controls (group 1, N = 10) and diabetes groups (group 2, N = 10). Dorsal skin was removed for routine histological tissue procedures. Hematoxylene and Eosin (HE), Masson's Trichrome and Periodic Acid Schiff (PAS) stainings, immunohistochemical connexin 43 (Cx43) and type IV collagen stainings were applied. Morphometry of epidermal thickness were also determined. Group 2 revealed decrease in epidermal thickness with disintegration of epithelium and decrease of dermal collagen fibers. Stratum spinosum were morphologically abnormal for group 2. Measurements of epidermal thickness revealed statistically significant decrease (P = 0.000). PAS staining for group 2 revealed disruption of the basement membrane. Epithelial scar formation, deterioration of transformation in the polyhedral cells, degradation of epidermis and decrease in PAS staining for vascular structures were observed, whereas the reticular dermis and hair follicles were normal. Collagen fiber density in group 2 were found to be prominently decreased in dermis with Masson's Trichrome staining. Evident decrease in immunostaining of Cx43 and type IV collagen were also shown in diabetic group in comparison to the controls. In conclusion, diabetes not only induced impairment of the epidermal integrity and deterioration in the epidermis via loss of gap junctions (the most prominent cellular junctional complex), but also caused dramatically negative impact on the dermal collagen content, and integrity of the basement membrane.