| Project/Area Number |
05671329
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Urology
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| Research Institution | Yokohama City University |
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Principal Investigator |
NOGUCHI Kazumi Yokohama City University School of Medicine Associate Professor, 医学部, 助教授 (10164675)
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| Co-Investigator(Kenkyū-buntansha) |
HOSAKA Masahiko Yokohama City University School of Medicine Professor, 医学部, 教授 (30106330)
KINOSHITA Yuzo Yokohama City University School of Medicine Associate Professor, 医学部, 助教授 (00186298)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1994: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1993: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Sertoli Cell / Leydig Cell / Testosterone / Paracrine Control / テストマテロン |
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| Research Abstract |
In the present study, we demonstrate the existence of a factor which stimulates testosterone production by mature mouse Leydig cells in a spent medium of immature rat Setoli cell cultures and show some new biochemical characteristics of this factor.
Using ultrafiltration apparatus with a molecular weight cut off of 10 kDa, Sertoli cell conditioned medium SCCM was concentrated. Fifteentimes concentrated rat SCCM stimulated testosterone production in a dose dependent fashion from 25 mul up to 50 mul. The activity came to a plateau at a dose of 100 mul. Leydig cell stimulating activity was retained by both a dialysis membrane and an ultrafiltration membrane with a molecular weight cut off of 10 kDa. However, activity was reduced by heating for 30 min at 60 C and lost after incubation with 0.1% trypsin for 1 h at 37 C.The activity was not retained by a Con A-agarose column and was demonstrated only in break-through fractions. HPLC gel filtration of 15 times concentrated SCCM preparation on TSK gel G3000 SW revealed activity at about 13 kDa. Both LH and SCCM significantly increased extracellular cAMP levels suggesting the activity of adenylcyclase activation of SCCM.We checked the enzyme activities of DELTA4 pathway from pregnenolone to testosterone. With the acute stimulation of LH,no change on the series of enzyme from pregnenolone to testosterone was revealed although testosterone production was stimulated to several times higher than the control. With SCCM treatment, same results were obtained although testosterone production was increased. Our SCCM preparation failed to show the activity stimulating Leydig cell testosterone production when incubated with a maximally stimulating dose of LH (10 IU/ml).
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