1997 Fiscal Year Final Research Report Summary
Positive Control of Gonadotropin Secretion by Androgen
| Project/Area Number |
07671744
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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 |
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)
TAKEDA Mitsumasa Yokohama City University, School of Medicine, Assistant Professor, 医学部, 講師 (70244499)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Pituitary gland / Gonadotropin / Testosterone / Positive Control |
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| Research Abstract |
We investigated the effects of testosterone (T) on FSH secretion from male rat anterior pituitary cells in cultures at the single cell level. Anterior pituitary cells cultured with or without 10 ng/ml T for 72 h were monodispersed and subjected to cell immunoblot assays for FSH.Cell blots specific for FSH were quantified by means of a microscopic image analyzer. The number of FSH-secreting cells detected as immunoreactive cell blots on the transfer membrane was increased up to 6 h incubation and represented 4.1% of total pituitary cells applied on the membrane at 6 h of incubation. The amount of FSH secreted by single cells varied from less than 20 to greater than 8,000 fg/cell/h. The mean FSH secretion from individual cells was increased in an incubation time-dependent manner up to 6 h. The number of FSH-secreting cells was not changed by the addition of 10 ng/ml of T into the culture medium at any time of incubation. T administration increased the mean FSH secretion by 64% after 3 h incubation, resulting in a shift to right in frequency distribution of FSH secretion from single cells. The total amount of FSH namely the sum of FSH secreted by each FSH-secreting cell was increased by 92% by the addition of T and 83.7% of this increase was attributable to an increase in FSH secretion from the largest secretor subgroup (greater than 5 pg/cell/3h). However, mean amounts of FSH secretion by the top 10 of the largest secretor subgroup were not different between control and T-treated groups.
The present study analyzed for the first time FSH secretion from rat anterior pituitary cells at the single cell level. The results suggest that stimulation by T of FSH secretion in vitro is not due to the increase in the number of FSH-secreting cells but due to the increase in FSH secretion from each cell.
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