한국재래 자에서 부화 후부터 성숙에 이르는 시기까지 황체형성호르몬 자극에 대한 고환내 testosterone 생성과 혈청내 황체형성호르몬, estradiol, IGF-I 및 testosterone 농도의 변화를 알아보기 위하여 부화 후 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 21, 28, 32, 44, 52 및 64주령(n=13마리/일령)의 한국재래 닭을 이용하여 방사면역측정법을 적용하여 이 연구를 수행하였다. 혈청내 estradiol의 농도는4주령과 비교하여 8, 12, 16, 21, 32 및 44주령에서는 차이가 없었으나 52주령과 64주령에서는 큰 폭으로 증가하였다. 혈청내 황체 형성호르몬의 농도는 $1~12$주령까지는 유의성이 없었고 14주령부터 32주령까지 점진적으로 증가한 다음 유의성 있게 감소하였으며 32주령에 최고치와 2주령에 최저치를 나타내었다. 혈청내 IGF-I의 농도는 $1~16$주령까지는 유의성 있게 증가하였으나 이후에는 변화가 없이 낮게 유지되었다. 혈청내 testosterone농도는 1, 2, 4 및 8주령에는 유의성이 없고 $10~32$주령까지 유의성있게 증가하였으며 $24~32$주령 및 $32~64$주령에서는 유의성이 없었다. 황체형성호르몬 자극에 대한 고환내 testosterone 생성은 $1~32$주령까지 유의성 있게 증가하였고 $44~64$주령까지는 큰 폭으로 감소하였다.
Changes in serum estradiol, insulin-like growth factor-1, leuteinizing and testosterone levels, and leuteinizing hormone-stimulated testosterone production per testis in vitro from hatching to adulthood were studied in Korean native chickens of 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 21, 24, 28, 32, 44, 52 and 64 weeks (n=13 chickens per group) of age. The changes in the profiles of the levels in the incubation medium of luteinizing hormone-stimulated (100 ng/mL) testosterone secretion per testis in vitro, and the serum LH, testosterone, estradiol, and insulin-like growth factor-I were determined by radioimmunoassay. Serum estradiol levels were not significantly different at week 4 compared to that of 8, 12, 16, 21, 32, :md 44. Significant decreases were observed at weeks 52 and 64. Serum leuteinizing hormone concentrations were not significantly different from 1 week to 12 weeks, increased gradually up to 32 weeks of age, and declined significantly thereafter; the highest value was at 32 weeks, and the lowest value was detected at 2 weeks of age. Serum insulin-like growth factor-I concentrations increased significantly from 1 week to 16 weeks, remained low and unchanged with advancing age. Serum testosterone concentrations were not significantly different at week 1 compared weeks 2, 4, 6, and 8. Significant increases were observed from 10 weeks to 32 weeks of age. Values at weeks 24, 28 and 32 and at weeks 32, 44, 52, and 64 were not significantly different. The highest value was at weeks 28 and the lowest value was detected at weeks 1 week. LH-stimulated testosterone production per testis in vitro increased gradually with age from 1 to 32 weeks and decreased significantly from 44 weeks to 64 weeks of age.
