1 人胎児に於ける成長ホルモンの研究
スポンサーリンク
概要
- 論文の詳細を見る
The role of pituitary growth hormone in foetuses during intrauterine life has been the subject of various controversy. In this report I presented firstly the results on the time of appearance of growth hormone, and its content in human foetal pituitary glands, and also its concentration in cord blood. Then I discussed the transplacental passage and finally reviewed the regulation of growth hormone secretion in foetuses and neonates. Human foetuses were collected at the time of artificial abortion and immediately washed with saline and kept in acetone. Growth hormone was extracted from acetone dried foetal heads or pituitary regions by homoginizing in saline and subjected to radioimmunoassay. 48 foetuses were investigated in total, their gestational age ranging from 6 to 20 weeks. None of the foetus at the 6th week in gestation contained measurable growth hormone. However, in the 7th week, 2 out of 7 foetus contained a few mμg of growth hormone and in the 8th week, 6 out of 8 contained 2 to 13.5 mμg. By the 9th week, growth hormone was detected in all of 3 foetuses in amounts of 6 to 30 mμg. Growth hormone content in foetal pituitary glands increased logarithmically thereafter. By the end of the 2nd month they contained up to 10 mμg and by the end of the 3rd month, 10 to more than a hundred. At the 4th month from a hundred to more than a thousand and by the end of 5th month, 40 μg of growth hormone were being stored in a pituitary gland. Growth hormone content per gram of wet weight of the foetus showed a great spurt between the 4th and 5th month of gestation as compared to the previous stage.<BR>Growth hormone concentration in cord blood was determined in 7 foetuses. One foetus at the 10th week of gestation contained 18 mμg/ml of growth hormone in its cord blood. At the 16th week, cord blood contained 40-120 mμg/ml of growth hormone.<BR>Transplacental passage has been denied in many protein hormones as was proved in case of growth hormone at the time of delivery. Judging from the high concentration of growth hormone in cord blood far beyond that observed in mothers, transplacental passage of growth hormone was reuld out in early stage of pregnancy as well.<BR>Time of appearance or synthesis of other pituitary hormones were reviewed, they range from the 7-8th week for growth hormone to 21st week for FSH.<BR>As for the regulation of foetal growth hormone secretion several reports were reviewed. Human neonates are known to respond to insulin induced hypoglycemia. (Cornblath et al. 1965). In simian foetuses and neonates within 24 hours after delivery, arginine infusion does not increase growth hormone concentration in blood as reported by Mintz et al.1969. Cornblath et al. reported in 1965, that glucose administration increased paradoxically the serum growth hormone level in human neonates, and that it is not until 15 days after delivery when glucose suppresses growth hormone concentration in blood, the ressponse usually seen in children and adults. Mintz also observed the same paradoxical rise of growth hormone in simian foetuses and neonates when glucose was administered.<BR>It has been the prevailing view that growth hormone is not indispensable for the foetal intrauterine growth and many investigators support this concept. Still foetal pituitary glands store and probably synthesize growth hormone as early as in 7 weeks of gestation and cord blood containes high level of growth hormone from the early stage of pregnancy as was just reported above. It is therefore suggested that foetal growth hormone may be playing an important role for the foetal growth and metabolism than was thought before.
- 日本内分泌学会の論文
著者
関連論文
- 1 人胎児に於ける成長ホルモンの研究
- Effect of Growth Hormone and/or Sex Steroids on Epinephrine?induced Lipolysis in Hypophysectomized Rats