Heap R B, Henville A, Linzell J L
J Endocrinol. 1975 Aug;66(2):239-47. doi: 10.1677/joe.0.0660239.
Tracer kinetic techniques have been used to measure the production rate, metabolic clearance rate and mammary uptake of progesterone in six experiments on two Jersey cowsmthe cows were surgically prepared so that the carotid artery, jugular vein and mammary vein concentrations of progesterone, and udder blood flow, could be determined in conscious animals without anaesthesia or stress. The mean production rate of progesterone was 173 +/- 23-3 (S.ET) mug/min, with values ranging from 80 to 276 mug/min in pregnancy. The metabolic clearance rate was 22-5 +/- 2-0 1/min, or 0-21 +/- 0-025 1/min/kg metabolic body weight. The mammary uptake of progesterone was low, 3-1 +/- mug/min, and udder uptake accounted for about 3% of progesterone production rate. During [3H]A1progesterone infusion, radioactivity was transferred from blood to milk, probably by diffusion down a concentration gradient. Progesterone accounted for more than 88% of the ether-soluble radioactivity recovered from milk.
在对两头泽西奶牛进行的六项实验中，采用示踪动力学技术来测量孕酮的生成速率、代谢清除率和乳腺摄取量。奶牛经过外科手术处理，以便在未麻醉且无应激的清醒动物身上测定颈动脉、颈静脉和乳腺静脉中孕酮的浓度以及乳房血流量。孕酮的平均生成速率为173±23.3（标准误）微克/分钟，在怀孕期间，其值范围为80至276微克/分钟。代谢清除率为22.5±2.0升/分钟，或0.21±0.025升/分钟/千克代谢体重。孕酮的乳腺摄取量较低，为3.1±微克/分钟，乳房摄取量约占孕酮生成速率的3%。在输注[³H]α-孕酮期间，放射性物质可能通过浓度梯度扩散从血液转移到乳汁中。从乳汁中回收的醚溶性放射性物质中，孕酮占比超过88%。
