study of histomorphometric changes in adult rats skin following injection of prp and ppp

background: prp (platelet-rich plasma) is a biological product that has shown significant therapeutic results compared to synthetic drugs and some traditional methods. the advantages of this method include: prp, compared to other biological materials, is easily prepared in clinic and the safety is high as well. objectives: we aimed to investigate the evaluation of histomorphometric properties after injection of plasma. methods: thirty rats were divided randomly into three groups: control group (normal saline), prp and ppp (platelet-poor plasma) groups. in order to prepare prp and ppp, blood samples (1cc) were collected through cardiac puncture and were centrifuged. the upper layer consisted of ppp and lower layer consisted of prp. the 2% calcium gluconate solution (100 µl) was added to platelet-rich plasma (200 µl) layer to activate platelet. after seven days, the dorsal skin samples were collected. they are cut into 5 to 6 μm thickness sections using paraffin embedding method and were stained by hematoxylin, eosin and masson’s trichrome. the epidermis, dermis and hypodermis layers of skin, the epithelial thickness of hair root sheath, maximum depth of hair follicles, the thickness of the whole skin, the number of sebaceous glands and hair follicles in the specified scale, finally the number of fibroblast cells and the percent distribution of connective tissue fibers were investigated in histometric structure of the skin and skin appendages. results: the results of this study indicated that systematic and controlled prp may have beneficial effects on the reconstruction and rehabilitation of the skin and its appendages. conclusions: the present study showed that growth factors in plasma especially prp, could be stimulated connective tissue fibroblast of dermal layer in the skin.