Abstract
This study was conducted to investigate the synthesis of previtamin D$_3$(PreD$_3$), lumisterol$_3$($L_3$) and vitamin $D_3$ ($D_3$) in dorsal skin of 8 week-old broiler chicks irradiated by UV light. The Hubbard line day-old broiler chicks were fed with vitamin D-depleted ration (or 3 weeks and with medium broiler diet for 5 weeks. The 3$\times$3cm area of dorsal skin was defeathered one day before the experiment. The 310nm UV light was utilized to irradiate the dorsal skin, which was separated into epidermis and dermis after irradiation. The irradiated epidermis was extracted with 60% ethyl acetate in n-hexane and PreD$_3$, $L_3$, D$_3$ and 7-dehydrocholesterol (7-DHC) were analyzed by HPLC. When UV light was treated for 0, 90 or 150min. the L$_3$ content in the separated epidermis was 219, 298 or 248ng/$\textrm{cm}^2$, respectively. The irradiation for 90min produced 79ng/$\textrm{cm}^2$ of L$_3$, and the synthesizing rate was 0.9ng/$\textrm{cm}^2$/min. The PreD$_3$ content was 23, 33 or 12ng/$\textrm{cm}^2$ when exposed for 0, 60 or 150min The 10ng/$\textrm{cm}^2$ of PreD$_3$ was produced for 60min. The D$_3$ was generated by 27ng/$\textrm{cm}^2$ when exposed for 90min. The 7-DHC contents were decreased gradually from initial 123 to 35ng/$\textrm{cm}^2$ when exposed for 150 min, showing the rate of disappearance as 0.6ng/$\textrm{cm}^2$/min.
본 연구는 8주령 브로일러 병아리 등 피부에 자외선을 조사하여 previtamin $D_3$ (PreD$_3$), lumisterol$_3$($L_3$) 및 비타민 $D_3$($D_3$)의 합성양을 조사코자 실시하였다. Hubbard 계통 브로일러 병아리를 비타민 D결집사료 (3주간)와 브로일러 중기사료 (5주간)로 사육하고 털을 뽑은 등 피부에 310nm의 자외선을 조사하였다. 조사시간은 0~150분간(0~0.79J/$\textrm{cm}^2$)으로 하였고 조사가 끝난 시료는 60%ethyl acetate n-hexane준액으로 추출하여 HPLC로 Pre$D_3$, $L_3$ , $D_3$ 및 7-dehydrocholesterol(7-DHC)을 분석하였다. 8주령 브로일러 등피부에 파장 310nm의 자외선을 0, 90 또는 150분간 조사하였을 때 L$_3$ 함양이 각각 219ng/$\textrm{cm}^2$, 298ng/$\textrm{cm}^2$, 또는 28ng/$\textrm{cm}^2$이었으며 90분간 조사로 79ng/$\textrm{cm}^2$양이 합성되었다. 이때의 합성속도(율)는 0.9ng/$\textrm{cm}^2$/min이었다. PreD$_3$ 함양은 0, 60또는 150분간 조사시 23ng/$\textrm{cm}^2$, 33ng/$\textrm{cm}^2$ 또는 12ng/$\textrm{cm}^2$이었으며 60분간 조사시 10ng/$\textrm{cm}^2$합성되었다. D$_3$함양은 0, 90 또는 150분간 조사시 5ng/$\textrm{cm}^2$, 32ng/$\textrm{cm}^2$ 또는 15ng/$\textrm{cm}^2$로서 90분간 조사로 27ng/$\textrm{cm}^2$량이 생성되었다. 7-DHC은 당초의 123ng/$\textrm{cm}^2$으로부터 계속 감소되어 150분간 조사시 53ng/$\textrm{cm}^2$량까지 내려갔다.