Growth hormone secretion in the rat as a function of age.
The first appearance of rat growth hormone (RGH) in serum was in the 19 day-old foetus. The level was high on the 21st day of gestation (129 +/- 7 ng/ml serum), it decreased after birth and descended to 17 +/- 2 ng/ml in the 15 day-old rat. After weanling it again rose to reach a plateau at 80 cays. The half-life and metabolic clearance rate (MCR) of RGH were compared in the 4 and 15 day-old rat and in normal and hypophysectomized adult rats after a single intravenous injection of hormone. As the MCR was essentially the same in all groups, serum RGH levels reflect the rate of hormonal secretion of the pituitary gland.
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D004986:Ether / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000378:metabolism; D013006:Growth Hormone / Q000097:blood*; D007016:Hypophysectomy; D008297:Male; D008657:Metabolic Clearance Rate; D011247:Pregnancy; D051381:Rats
D004986:Ether; D013006:Growth Hormone