|Budget Amount *help
¥8,000,000 (Direct Cost : ¥8,000,000)
Fiscal Year 1996 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1995 : ¥7,200,000 (Direct Cost : ¥7,200,000)
Age-Related changes in the Serum Levels of Inhibin, FSH,LH and Testosterone in Holstein Bulls : Five-hundred-fifteen Holstain Bulls were divided into age-groups as 0.2,0.5,1,2,3,4,5,6,7 and 8years old. Bood samples were taken, and sera were separated immediately after collection by centrifugation and stored at -20ﾟCC until hormone assay. Serumlevel of inhibin, folicle stimurating hormone (FSH), luteinizing hormone (LH). and testosterone were assayd by radio immuno assay (RIA). The plasma levels of inhibin were the highest in the young bulls before 1year old (0.2year, 2.46ng/ml ; 0.5year, 2.60ng/ml) and gradually decreased with age. In contrast to inhibin, serum levels of FSH were the low in the young bulls before 1year old (0.2year old, 5.83ng/ml) and gradually increased with ages. The serum levels of LH were suggested a weak tendency to increase with age but not so clear as that of FSH.Plasma levels of testosterone were low at postnatal period and increased gradually with age. The pre
sent results clatified age-related changes of inhibin, FSH.LH and testosterone. Seru, levels of inhibin were correlated negatively with FSH before the onset of the puberty.
Serum Inhibin, FSH,LH and testosterone Levels, Testicular inhibin and Testosterone Contents and Immunohitochemical Localization of Inhibin in Holstein Bull Calves from Birth to Puberty : Teste sinhibin contents were the highest in neonatal calves (3.3ng/g wet weight) and decreased gradually with age. At 8.6month-old bull calves, they were 0.52ng/g. There was positive correlationship between the inhibin content and age. On the otherhand, testosterone contents did not show any age-related changes in this experimental period.
Seruminhibin levels were very high from neonatal period to 1.8month-old calves (7.09ng/g wet weight) and decreased gradually with age. At 8.6month-old bull calves, they were 1.98ng/g. There was positive correlationship between the inhibin content and age. Serum FSH and LH levels were greater at 1.6month-old than other age groups, but clear increrasing or decreasing with age was not found in this sutdy. Serumtestosterone levels were increased with ages, but there was no clear correrationship with age.Positive reactions for inhibin localization were clearly detected in the Sertoli cells of the seminiferous tubules from neonatal to 2.3month-old calves. After that, their intensities were decreased with age, and they were not detected immunohistochemically over 6month-old claves. They were also not detected in any Sertoli cells of over 6month-old calves. Less