title: Effects of calcitonin on epidermal regeneration and collagen synthesis in rabbits with experimental wounds.
abstract: The cellular and metabolic effects induced by calcitonin on regenerative epidermal cells, fibroblasts and collagen fibers during wound healing were studied in rabbits. Electron microscopy revealed marked changes at 2 and 5 days post-wounding in epidermal cells and fibroblasts in calcitonin-treated rabbits such as: an increase in keratohyaline granules, tonofilaments, polysomes and a hypertrophy of nuclei in the epidermal cells. Fibroblasts are hypertrophied and surrounded by large areas of mature collagen fibers, namely at 5 and 14 days. Electron microscopic autoradiography revealed an increase in the incorporation of 3H-thymidine mostly in the nuclear chromatin, 3H-uridine in the nucleoli, 3H-leucine in the endoplasmic reticulum, polysomes and newly formed keratin layers, and 3H-proline over fibroblasts and collagen fibers. Most of the cellular and metabolic effects are evident at 2.5 hours and gradually decline by 5 and 24 hours of hormone administration. Scanning electron microscopy showed changes in the keratin pattern and collagen fibers. At 5 days after wounding and calcitonin treatment, a typical scaly pattern of keratin can be noted while in controls it is smooth and homogeneous. At 14 days post-wounding the collagen fibers are hypertrophied, with an extensive network of fibrils in calcitonin-treated rabbits. These findings demonstrate that synthetic salmon calcitonin stimulates protein synthesis, keratinogenesis and collagen formation in epidermal cells and fibroblasts during wound healing.
mesh_terms: D000818:Animals; D002116:Calcitonin / Q000494:pharmacology*; D003094:Collagen / Q000096:biosynthesis*; D004817:Epidermis / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D007633:Keratins / Q000096:biosynthesis; D007930:Leucine / Q000378:metabolism; D008297:Male; D011392:Proline / Q000378:metabolism; D011817:Rabbits; D012038:Regeneration / Q000187:drug effects; D013936:Thymidine / Q000378:metabolism; D014529:Uridine / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D007633:Keratins; D002116:Calcitonin; D003094:Collagen; D011392:Proline; D007930:Leucine; D013936:Thymidine; D014529:Uridine