1998 Fiscal Year Final Research Report Summary
Physiological role of oxytocin on androgen production in the testis.
| Project/Area Number |
09660342
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied veterinary science
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| Research Institution | Osaka Prefecture University |
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Principal Investigator |
SAWADA Tsutomu Osaka Prefecture University, College of Agriculture, Professor, 農学部, 教授 (60081600)
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| Co-Investigator(Kenkyū-buntansha) |
KAWATE Toshinori Osaka Prefecture University, College of Agriculture, Research Associate Assistan, 農学部, 助手 (80221901)
TAMADA Toshimichi Osaka Prefecture University, College of Agriculture, Assistant Professor, 農学部, 講師 (10155252)
INABA Toshio Osaka Prefecture University, College of Agriculture, Associate Professor, 農学部, 助教授 (00137241)
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| Project Period (FY) |
1997 – 1998
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| Keywords | androgen / local hormone / male goat / male rat / oxytocin / prostaglandin F2 alpha / testis / testosterone |
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| Research Abstract |
(1) The relationships among androgens (A), oxytocin (OT), and prostaglandin F2alpha(PGF2alpha), all of which are produced in Leydig cells, are not known. In this study, the effects of administration of OT on the production of A and PGF2alpha, or of PGF2alpha on the production of A and OT, in adult male rats were investigated. First, 100 ng of OT or 50*g of PGF2alpha was injected into a testis twice daily for 4 days. Some rats were injected with 10 IU of human chorionic gonadotropin (hCG) through the external jugular vein 1.5h before being sacrificed. hCG was given to stimulate the production of A.Rats were sacrificed and testicular hormone concentrations were measured. OT decreased T concentration and increased concentrations of 5alpha-dihydrotestosterone (DHT) and PGF2alpha. PGF2alpha decreased T concentration and tended to increase DHT concentration, but had no effect on OT.The injection of hCG increased the concentration of T and DHT, but the effects of OT or PGF2alpha on A producti
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on were similar whether hCG was injected or not. These results indicate that in adult rat testis, OT and PGF2alpha promote the metabolism of T, and suggest that the action of OT is mediated through PGF2alpha. (Prostaglandins & other Mediators 55 : 121-126, 1998)
(2) Gene expression, immunohistochemical localization, binding, and effects of OT on A production in the testis of adult goats were studied. Using polymerase chain reaction (P CR) analysis we had been able to detect OT gene hanscripts in the goat testis. Immuno- histochemistry revealed that both OT and neurophysin epitopes were expressed together in the intratubular regions, especially in the Sertoli cells, suggesting the production of OT in these cells. However, enzyme immunoassay found no difference in OT concentration between testicular arterial plasma and venous plasma. Saturable, specific [3H]-OT binding sites were present in membrane fraction of the goat testis. Scatchard analysis indicated an apparent affinity of 42*7 L/nmol and binding capacity of 24*4 fmol OT bound/mg DNA.In vitro treatment of goat testes for 6 h with 100 nM OT led to a 3.5-fold increase (P<0.00l) in DHT production in spite of the induced decrease in testosterone, suggesting that OT not only affects testosterone production but also modulates its conversion to DHT.These results indicate that the goat testis produces OT, which may be involved in the local control of A biosynthesis. (Theriogenology : submitting) Less
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