| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1987: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1986: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
In an attempt to elucidate the functional role of the three zones of adrenal cortex in steroidogenesis, the localizations of microsomal cytochromes P-450(P-450(17<Alpha>,lyase)and P-450(C21)) were investigated in the guinea pig adrenal cortex by the direct method of the peroxidase labeled antibody technique. The immunocytochemical localizations of these cytochromes were proved to be the smooth surfaced endoplasmic reticulum. P-450(17<alpha>,lyase) was found to be distributed in the zona fasciculata, especialy in their externa, and less in the zona reticularis. The zona glomerulosa was negative for immunohistochemical staining. On the other hand, P-450(C21) was distributed in all three zones in the adrenal cortex.
The cytochrome P-450 contents and their activities were measured with the microsomes prepared from the outer zone(zonae glomerulosa and fasciculate) and from the inner zone(zona reticularis) of guinea pig adrenals. Using ELISA, the ratio of P-450(C21) content in the inner zone to that in the outer zone microsomes was estimated to be 1.24 and that of p-450(17<alpha>,layse) content to be 0.75. 21-Hydroxy-lase activities were higher in the inner zone microsomes, which were in good agreement with the relative p-450(C21) content. 17<alpha>-Hydroxylase and C-17-C-20 lyase activities were 5-6 fold greater in the outer than in the inner zone microsomes, which could not be explained only with the P-450 (17<alpha>,lyase) contents in the two zones. The effects of ACTH on the zonal distribution of microsomal cytochrome P-450's and their steroidogenic activities were also investigated.
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