Histological, histometrical and thyroid hormones serum level evaluation after chronic nicotine exposure in mice

Nicotine is an ingredient of cigarette smoke that has a lot of psychological and physical effects on addicted persons. The aim of this study was to evaluate nicotine effects on functional and histological alteration in thyroid gland that has important role on metabolic activities. In this experimental study, 40 mature male mice [25-30 gr] were divided to one control group and 3 experimental groups that received nicotine with dosage of 100, 200 and 400 micro g/kg via oral gavage once a day for 60 days. Then, T[3], T[4] and TSH serum levels were measured and histomorphometric evaluation of thyroid gland was done. Significant decrease in body weight and thyroid follicular epithelial height and significant increase in serum level of T[3] were noted. This study showed that nicotine can cause alteration on metabolic activities of thyroid gland via the increase of T[3] serum level and the decrease of follicular epithelial height

Role of fibrocytes [CD34+] derived from peripheral blood in the pathology of dermal fibrosis in a model of scleroderma

Peripheral blood fibrocytes are a newly identified circulating leukocyte subpopulation that migrates into injured tissue where it may display fibroblast-like properties and participate in wound healing and fibrosis of skin and other organs. In this study, fibrocyte recruitment to skin in a bleomycin-induced dermal fibrosis model of human scleroderma in vivo was studied. Sections of skin from normal mice [control group] and bleomycin-treated C57BL/6 mice [Experimental group] were stained for Procollagen a2 Type I and CD34 and the double stained cells, and also fibrocytes were counted in the tissue sections. There were more fibrocytes in the dermis of experimental group than control group. There was no significant difference in fibrocyte number between skin samples with 1 week bleomycin treated and 3 weeks treated samples. We also found that fibrocytes [CD34+ and procollagen+] were mainly localized in clusters around blood vessels in the dermis and also individually close to epithelium. Our data suggest an important role of fibrocytes in the pathology of dermal fibrosis