Search Results

1.The Effect of alpha-MSH on the Morphologic Changes, Survival, and Melanization of Cultured Human Melanocytes.

Korean Journal of Dermatology 1998;36(2):280-285

BACKGROUND: The effects of melanocyte stimulating hormone(MSH) on the integument of many species, including mammals, are well known. The significance of MSH as a physiological regulator of cutaneous pigmentation in humans is still controversial. Although the administration of MSH results in skin darkening, previous reports suggest that cultured human melanocytes are relatively unresponsive to this peptide. This may be related to the conditions under which the melanocytes were cultured. OBJECTIVE: The purpose of this study was to investigate the effect of alpha-MSH on the morphological changes, survival, and melanization of cultured human melanocytes in a basal medium without any mitogen. METHOD: We examined the morphological changes, number and melanin contents of cultured human melanocytes in control(absence of alpha-MSH) and experimental groups(presence of 10(-8) M, 10(-7) M, and 10(-6) M alpha-MSH). RESULTS: 1. There were no significant morphological changes of cells between the control and experimental groups after 24, 48, and 72 hours' culture. The number and length of melanocyte dendrites showed no significant difference between the groups after 24, 48, and 72 hours' culture. 2. The number of melanocytes in the experimental groups(presence of 10(-7) M, and 10(-6) M alpha-MSH) were significantly higher than the number of melanocytes in control group after 72 hours culture(p<0.05). This effect of alpha-MSH was dose-related. 3. The melanin contents slightly increased in the experimental groups. The significant difference between the groups was showed in the presence of 10(-8) M alpha-MSH. CONCLUSIONS: alpha-MSH has no effect on the morphology, but increases the survival of cultured human melanocytes and has a melanogenic effect.
alpha-MSH* ; Dendrites ; Humans* ; Mammals ; Melanins ; Melanocyte-Stimulating Hormones ; Melanocytes* ; Pigmentation ; Skin

5.A Study of Skin Color by Melanin Index according to Sex, Age, Site and Skin Phototype in Koreans.

Mu Hyoung LEE ; Tuk Woo LIM ; Mu Hyoung LEE

Annals of Dermatology 2002;14(2):71-76

BACKGROUND: Skin color is determined by many factors including melanin and nonmelanin pigments like hemoglobin and extraneous chemicals. Various factors such as race, sex, and age have been reported to have an influence on skin color. METHODS: Measurement of malanin index (M-index) was made by reflectance spectropho-tometer at three different sites including forehead, abdomen and forearm in total 800 healthy subjects consisting of 100 males and 100 females of neonates (three days after birth) and children (male:8.08±0.84, female:8.03±0.80, total :8.06±0.82 years of age), ado-lescence (mate:13.89± 0.76, female:13.96±0.79, total:13.93±0.78 years of age), and adults(male:24.26±0.82, female:24.40±0.89, total:24.33±0.86 years of age). We also investigated the change of M-index by each skin phototype of college students determined by Fitzpatrick classification. RESULTS: From the birth to the puberty, sex difference of melanin index was generally not not-ed, but adult females showed lower levels of melanin index in all sites measured. M-index in-creased from birth to adolescence, and decreased after adulthood. Forehead showed highest melanin index compared with other sites. Increase of M-index was noted as skin phototype goes from III to V. CONCLUSIONS: Factors including sex, age, body sites and skin phototype have a significant in-fluence on the changes of skin color in humans.
Abdomen ; Adolescent ; Adult ; Child ; Classification ; Continental Population Groups ; Female ; Forearm ; Forehead ; Humans ; Infant, Newborn ; Male ; Melanins* ; Parturition ; Puberty ; Sex Characteristics ; Skin*