2004 Fiscal Year Final Research Report Summary
The effects of sex hormone on growth plate chondrocyte.
| Project/Area Number |
14571355
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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 |
Orthopaedic surgery
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| Research Institution | Tohoku University |
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Principal Investigator |
YAMADA Norikazu Tohoku University, Hospital, Research Associate, 病院, 助手 (90333806)
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| Co-Investigator(Kenkyū-buntansha) |
OONUMA Masahiro Tohoku University, Hospital, Research Associate, 病院・助手 (90344663)
KAWAMATA Tomomaro Tohoku University, Hospital, Research Associate, 病院・助手 (70333804)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Growth Plate chondrocyte / Castration / Testosterone / Apoptosis / エストロゲン |
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| Research Abstract |
Sex hormones play important roles in the regulation of chondrocyte proliferation, maturation and death in epiphyseal growth plate. We investigated the effects of male castration on the cell kinetics of chondrocytes, defined by the numbers of proliferating and dying cells. The growth plates of normal rabbits and castrated at 8 weeks of age were obtained at 10, 15, 20 and 25 weeks old. They were stained for apoptotic and proliferating chondrocytes using immunostaining for caspase-3 and PCNA. The castrated rabbits showed higher caspase-3-positive and lower PCNA-positive ratios than the corresponding normal groups. In addition, the number of chondrocytes in the castrated rabbits was less than that of the normal ones at the same age. Our study suggested that castration led an increase of apoptosis and decrease of proliferating ability in growth plate chondrocytes.
Then, we cultured chondrocytes to investigate the effects of sex hormone on chondrocytes in vitro. 17-day-old fatal chick sterno was obtained and revealed by H-E stain to be composed of hypertrophic chondrocytes in 1/4 of cranial side and premature chondrocytes in 1/2 of caudal side. We obtained 5mm cranial and 8mm caudal side of sterno and cultivate them according to Gerstenfeld's method. The RNA of the cultured chondrocytes was extracted and reversetranscription-polymerase chain reaction (RT-PCR) was performed. The cranial chondrocytes presented type 10 collagen and the caudal ones type 2 collagen. That indicated that the former is mature hypertrophic chondrocyte and the latter premature chondrocyte. Sex hormone load test was performed with the culture system. Testosterone and estrogen at 10-10,10-9,10-8,10-7,10-6mol/l were added in hypertrophic and premature chondrocyte. The ALP activity, proliferative activity, cell death, mRNA of type 2 and 10 collage were tested. Testosterone stimulated cell proliferation, and estrogen stimulated cell death.
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