Christenson R K, Ford J J, Redmer D A
J Reprod Fertil. 1985 Sep;75(1):247-53. doi: 10.1530/jrf.0.0750247.
The crossbred gilts studied were aged 80 days (prepubertal), 180 days (prepubertal or postpubertal) and 260 days (postpubertal or pregnant). Estimates of metabolic clearance rate (MCR) of oestradiol and progesterone were consistently less (21 and 27%) in plasma than in blood, and these differences were not influenced by age of gilt. The MCR (1/day per kg body weight) for oestradiol and progesterone in plasma was greater (P less than 0.05) for 80-day-old prepubertal gilts than for older gilts. The MCR values of oestradiol and progesterone were similar in 180-day-old and 260-day-old gilts independent of reproductive state. Production rate (PR) of oestradiol and progesterone increased with age (80-180 days), and age and reproductive state differences were much more pronounced for PR of progesterone than of oestradiol. These results support the hypothesis that a reduction in the MCR and an increase in PR of oestradiol and progesterone in the gilt are associated with the process of pubertal development, and changes in gonadal steroid concentrations appear not to alter the MCR of oestradiol and progesterone.
所研究的杂交后备母猪年龄分别为80天（青春期前）、180天（青春期前或青春期后）和260天（青春期后或怀孕）。雌二醇和孕酮的代谢清除率（MCR）估计值在血浆中始终低于血液（分别低21%和27%），且这些差异不受后备母猪年龄的影响。80日龄青春期前的后备母猪血浆中雌二醇和孕酮的MCR（每千克体重每天的清除率，单位为1/天）高于年龄较大的后备母猪（P<0.05）。180日龄和260日龄的后备母猪，无论生殖状态如何，其雌二醇和孕酮的MCR值相似。雌二醇和孕酮的生成率（PR）随年龄增长（80 - 180天）而增加，且孕酮PR的年龄和生殖状态差异比雌二醇更为明显。这些结果支持了这样的假设，即后备母猪中雌二醇和孕酮的MCR降低以及PR增加与青春期发育过程相关，且性腺类固醇浓度的变化似乎不会改变雌二醇和孕酮的MCR。
