CYTOLOGIC AND METABOLIC EFFECTS OF PROSTAGLANDINS ON RAT SKIN

[摘要] The cellular and metabolic effects of exogenous prostaglandins E1, E2 and F2.alpha. (PGE1, PGE2 and PGF2.alpha.) were studied in the skin of rats by using scintillation counting, autoradiography, EM and scanning electron microscopy. Radioactivity measurements demonstrated that PG of the E series induced a marked increase in the incorporation of [3H]leucine, [3H]thymidine, [3H]uridine and [3H]proline in the rat skin, mostly at 1 h, whereas PGF2.alpha. inhibited this phenomenon. Light microscopic autoradiography revealed an increased incorporation of [3H]leucine in the cytoplasm of hyperplastic epidermis of PGE-treated rats; the incorporation of [3H]thymidine, [3H]uridine and [3H]proline was significantly increased over the epidermal nuclei, nucleoli, and the collagen fibers of PGE-treated rats. EM revealed ultrastructural changes of the epidermal cells and fibroblasts following PGE administration, including an increase in polyribosomes, endoplasmic reticulum, keratohyaline granules and enlarged intercellular spaces; PGF2.alpha. induced advanced cytolysis and cell disintegration, with increased lysosome formation. Scanning electron microscopy showed hypertrophied collagen fibers in PGE-treated rats; a disruption and disintegration of collagen fibers occurred in PGF2.alpha.-treated rats. The level of PGE1 in the skin of treated rats was markedly elevated compared to those of controls. PG apparently are potent regulators for the epidermal cell ultrastructure and metabolism and for collagen synthesis.