アブストラクト(14巻3号:神奈川歯学)

神奈川歯学

Japanese

Title : ラット顎下腺におけるAndrogen代謝 - 特に5α-Reductaseの性差に関する研究 -
Subtitle : 原著
Authors : 小鹿真理
Authors(kana) :
Organization : 神奈川歯科大学生化学教室
Journal : 神奈川歯学
Volume : 14
Number : 3
Page : 206-220
Year/Month : 1979 / 12
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「抄録」 Testosterone-4-14C(14C-T)および5α-Dihydrotestosterone-4-14C(14C-DHT)をそれぞれラット顎下腺のマイクロゾーム画分とインキュベートすると, Tの代謝物としてDHTおよび5α-Androstane-3α, 17β-diol(3α-Diol)が, さらにDHTの代謝物として3α-Diolが認められた. このことより, ラット顎下腺に5α-reductase, 3α-hydroxysteroiddehydrogenaseの存在が確認された. 5α-reductaseのKm値は, 雌が1.02×10-6Mであるのに対し, 雄のそれのKm値は二つ存在し, その値は, 1.12×10-6Mおよび1.01×10-5Mであった. 3α.hydroxysteroiddehydrogenaseのKm値は雄が4.34×10-6M雌が1.61×10-6Mであった. また5α-reductaseの至適PH, 至適温度はそれぞれ7.4約37℃であった. 以上の結果より, ラット顎下腺にT→DHT→3α-Diolの代謝が存在し, 顎下腺が男性ホルモン標的臓器であることが確認された. しかもT代謝の性差というものが, 5α-reductaseのTに対する親和性の違いによるものであることが示唆された.
Practice : 歯科学
Keywords :

English

Title : Proprties of 5α-Reductase in Rat Submandibular Gland - Sexual Differnce of the Enzyme
Subtitle :
Authors : Shinri Koshika
Authors(kana) :
Organization : Department of Biochemistry, Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 14
Number : 3
Page : 206-220
Year/Month : 1979 / 12
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : Each of testosterone-4-14C and 5α-dihydrotestosterone-4-14C was incubated with subcellular fractions obtained from homogenate of rat submandibular glands in the presence of several cofactors at 37℃ for 20 min. in an atomosphere of 95%O2 and 5%CO2. 5α-Reductase was mainly demonstrated in the microsomal fractien, while 3α-hydroxysteroiddehydrogenase was found to be in both mitochondria and the microsomal fraction to an identical degree. The two enzymes prefered NADPH as cofactor to NAD and NADH. Apparent Michaelis constant (Km) of 5α-reductase for testosterone in the female rat was 1.02×10-6M. Whereas, two Kms of 5α-reductase for testosterone in the male were determined as 1.12×10-6M and 1.01×10-5M. However, the Km of 3α-hydroxysteroiddehydrogenase for 5α-dihydrotestosterone in the male was 4.34×10-6M and that in the female was 1.61×10-6M. The optimal pH and temperature of 5α-reductase were 7.4 and 37℃, respectively. The results taken togeteer show that 5α-reductase and 3α-hydroxysteroiddehydrogenase definitely exist in the rat submandibular gland and that the submandibular gland of the rat is reasonably demonstrated as an androgen target organ. And they suggest that sexual difference of the rat submandibular gland may depend on affinity of 5α-reductase for testosterone in consideration of the difference of the Km between male and female.
Practice : Dentistry
Keywords :