Immunohistochemical detection of transforming growth factor beta 2 and insulin like growth factor 1 in labial tissues of treated and non treated diabetic rats

ABSTRACT

The purpose of this study was to detect transforming growth factor beta - 2 [TGF-beta2] and insulin like growth factor-1 [IGF-1] in the treated and non treated diabetic labial tissue in rat. Twenty four male's albino adult rats weighting between 150-200g each, were used throughout the experiment. They were housed under similar conditions. After determination of fasting blood glucose level for all animals, they were randomly divided into two main groups Group I [control group] consisted of 8 rats, each animal received 0.2 ml citrate-buffered saline solution PH 4.5. Group II [diabetic group] this group consisted of 16 rats for induction of diabetes. The animals were given a single inter-peritoneal of streptozotocin dissolved in citrate-buffered saline solution PH 4.5 [0.2ml/rat] with equivalent dose of 50ml/kg body weight. This group was divided into two subgroups Subgroup A, which consisted of 8 rats used as diabetic non treated group. Subgroup B, It consisted of 8 rats, each rat received gliclazide [diamicron] dissolved in distilled water [20 mg/kg p.o.] with gastric tube daily before feeding the animals. All rats in group 1, subgroup A and subgroup B were sacrificed at the same time after eight weeks by using a large dose of anesthesia. The specimens were taken from the lip of all rats, fixed, processed for paraffin section, cut and mounted on slides treated to enhance tissues adherence. Then the immuono-histochemical staining for TGF beta-2 and IGF-1 were processed to all specimens. The results of this study, In control group, TGF-beta 2 were detected in the basal cell.layer of epithelium and the lamina propri of the mucous membrane and skin and also were detected in the hair follicles, it were detected in the connective tissues but not the glandular epithelium of the labial minor salivary gland. In group II [sub group A], detection of TGF-beta 2 in the same sites as control group but with more reaction than it. In group II [sub group B], TGF-beta 2 detections were more than group 1 and group II [sub group A]. IGF-1 were detected in control group in the basal cell layer of epithelium and the lamina propri of the mucous membrane and skin but more than TGF-beta 2, it were also detected in the sebaceous gland itself but not in hair follicles, in the labial minor salivary gland neither detection of IGF-1 in glandular epithelium nor in the connective tissues. In group II [sub group A], the same results as control group in the mucous membrane and skin but with more reaction, in the labial minor salivary gland there were some detection in the glandular epithelium and connective tissues. In group II [sub group B], the same results as control group in the mucous membrane skin but with more reactions and as the labial minor salivary gland. Based on the previous results we can conclude that TGF-beta 2 and IGF-1 play an important role in regulation of proliferation and differentiation of keratinocytes, fibroblasts, and endothelial cells in the skin and mucous membrane of the lip in normal, diabetic none treated and treated rats. TGF-beta 2 controls hair cycling and regulates myogenesis of muscles and the activity of labial minor salivary gland in the lip of normal, diabetic none treated and treated rats. IGF-1 control the sebaceous gland secretion in the lip of normal, diabetic none treated and treated rats. It regulates the activity of labial minor salivary gland in the lip of diabetic none treated rats