Parr R A, Davis I F, Miles M A, Squires T J
Department of Food and Agriculture, Werribee, Australia.
Res Vet Sci. 1993 Nov;55(3):306-10. doi: 10.1016/0034-5288(93)90099-2.
To study the inverse relationship between feed level and concentrations of peripheral plasma progesterone, 36 ovariectomised ewes were fed rations at levels calculated to maintain liveweight (M). On the seventh day, the ewes were given an intravenous infusion of progesterone and the metabolic clearance rate (MCR) was calculated. The ewes were then randomly allotted to receive either 1/2M, M or 2M rations for seven days at which time the infusion and blood sampling schedules were repeated. The mean (SE) MCR of infused progesterone in ovariectomised ewes fed either 1/2M, M or 2M rations for seven days was 7.1 (0.59), 9.9 (1.64 and 13.0 (1.19) litre h-1 kg-1 of liveweight, respectively. Differences in MCR of progesterone between ewes fed 1/2M and 2M rations were significant (P < 0.05). The inverse relationship between level of feed intake and plasma progesterone concentration was attributed to differences in clearance rate of progesterone rather than to changes in the entry rate of the hormone into the blood.
为研究采食量与外周血浆孕酮浓度之间的反比关系，给36只去卵巢母羊饲喂按维持体重计算的日粮水平（M）。在第7天，给母羊静脉输注孕酮并计算代谢清除率（MCR）。然后将母羊随机分配接受1/2M、M或2M的日粮，持续7天，此时重复输注和采血计划。给去卵巢母羊饲喂1/2M、M或2M日粮7天后，输注孕酮的平均（标准误）MCR分别为7.1（0.59）、9.9（1.64）和13.0（1.19）升·小时⁻¹·千克⁻¹体重。饲喂1/2M和2M日粮的母羊之间孕酮MCR的差异显著（P<0.05）。采食量水平与血浆孕酮浓度之间的反比关系归因于孕酮清除率的差异，而非激素进入血液的速率变化。
