The Effects of Endothelin-1 from Ultraviolet (UV) B-irradiated Cultured Human keratinocytes on Proliferation and function on the Cultured Human Melanocytes / 대한피부과학회지

BACKGROUND: The regulatory rnechanisrns of melanocytes underlying ultraviolet(UV) melanogenesis have been an interest tu many investigators. They have shown that several materials produced and secreted frorn norm il human keratinocytes play roles as mitogens of human melanocytes, and demonstrated that UVB exposure stirnulated highly the paracrine linkage of endothelin(ET) be tween keratinocytes and melanocytes. It suggest that ET is one of keratinocytes-derived intrinsic mitogens in UVB induced hyperpigmentation. OBJECTIVE: To evaluate whether ET secreted from keratinocytes under the UV irradiation works as paracrine effects such as melanocyte pro)iferation and function, the present, study was under taken. METHODS: Primary kevatinocytes and rnelanocytes cultures from neonatal foreskins were grown in complete MCDB 154 medium. Cultured human keratinocytes were irradiated with UVB 50mJ/ cm2. Twenty fours hour later, conditioned medium of keratinocytes was added into the growth medium of melanocytes of concentration in 10%, 20%, and 30%, respectively. Four days later, in order to detect of melanocytes proliferat.ion and function, number of melanocytes, melanin granules and tyrosinase activity v ere measured. RESULTS: J. The number of me anocytes were higher increase in groups of incubation with conditioned medium of irradiated keratinocytes than that of incubation with conditioned mediurn of irradiated keratinocytes and treatment of anti-ET-1(5ug/ml)(p>0.05). 2. The melanin contents were significantly higher increase in groups of incubation with conditioned medium(20%, 30%) of irradiated keratinocytes than that of incubation with conditioned medium of irradiated keiatinocytes and treatment of anti-ET-1(5ug/ml)(p<0.05). 3. The tyrosinase activity of melanocyte incubated with 30% COllcentration of conditioned medium from cultured keratinocyte irradiated with UVB was significantly higher increase than that of melanocyte incubated with 30% concentration of conditioned mediurn from cultured keratinocytes irradiated with UVB and treated with anti-ET-1(p<0.05). CONCLUSION: This stud provided an important confirmation of the proposal that ET-1 is intrin sic factor for proliferation and differentiation of human melanocytes. These findings suggest that keratinocyte derived ET-1 make a considerable effect on human melanocyte proliferation and function in UV melanog nesis.

Correlation between Plasma Endothelin-1 Concentrations and Pulmonary Hypertension Associated with Congenital Heart Defects

PURPOSE: Endothelin-1 is the most potent vasoconstrictor. This study was investigated the correlation of plasma endothelin-1 and pulmonary hypertension associated with congenital heart defect. METHODS: We evaluated the concentration of ET-1 in 24 cases of congenital heart disease diagnosed at the Department of Pediatrics, Pusan National University, from December 1993 to September 1994. The patients were divided into 2 groups according to mean pulmonary arterial pressure: Pulmonary artery hypertension group(Group I) and normal pulmonary artery pressure group(Group II). Between 2 groups, there was no statistical significance in mean age, sex and oxygen saturation. GroupI included 9 patients of VSD and 1 patient of COA. Group II included 9 patients of VSD, 3 patients of TOF and 1 patient of PS, 1 patient of PS with DORV. RESULTS: The results were summarized as follows; 1) The mean pulmonary arterial pressure and pulmonary-to-systemic flow ratio (Qp/Qs), pulmonary vascular resistance in GroupIwere significantly higher than those in Group II. 2) The plasma concentrations of ET-1 in GroupI was significantly higher than those in Group II. 3) But there were no statistical significance between the concentrations of ET-1 and the mean pulmonary artery pressure, Qp/QS, pulmonary vascular resistnace. CONCLUSIONS: Based on these results, plasma ET-1 concentraions were elevated in patients with pulmonary hypertension associated with congenital heart defects.