BACKGROUND: @entity927 has an inhibitory action on ultraviolet (UV) B-induced melanocyte activation. This study examined the sex differences in the inhibitory action of @entity927 on UVB-induced melanocyte activation. METHODS: We irradiated the eye and ear of male and female @entity19 with UVB at a dose of 1.0 kJ/m(2) using a 20SE sunlamp. We orally administered @entity927 (750 mg/kg/day) at 30 min before UVB exposure. RESULTS: @entity927 inhibited the UVB-induced epidermal melanocyte activation, and the effect was more remarkable under UVB eye irradiation than under UVB ear irradiation. Furthermore, the melanocyte activity suppression effect was stronger in female @entity19 than in male @entity19 . Following the administration of @entity927 , the female displayed increased blood levels of b-endorphin and  -opioid receptor and @entity53 receptor b expression in comparison to the male. Furthermore, the effect of melanocyte activity suppression in the female @entity19 was decreased by the administration of @entity440 (antagonist of @entity172 receptor) or @entity836 (antagonist of  -opioid receptor). CONCLUSIONS: These results suggest that the suppression by @entity927 of the UVB-induced melanocyte activation (UVB sensitivity) is stronger in female @entity19 than in male @entity19 , and that female hormones and b-endorphin play an important role in this sex difference. This article is protected by copyright. All rights reserved.

The gender differences in the inhibitory action of UVB-induced melanocyte activation by the administration of XXXX .

@entity172 :: ('MESH:D004967', 'Chemical') :: ['estrogen'] @entity836 :: ('MESH:D009271', 'Chemical') :: ['naltrexone'] @entity440 :: ('MESH:D013629', 'Chemical') :: ['tamoxifen'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity53 :: ('MESH:D004958', 'Chemical') :: ['estradiol'] @entity927 :: ('MESH:D014148', 'Chemical') :: ['tranexamic acid', 'Tranexamic acid']
@entity927 :: (MESH:D014148,Chemical) :: ['tranexamic acid']
