Newton G R, Schillo K K, Edgerton L A
Department of Animal Sciences, University of Kentucky, Lexington 40546-0215.
Biol Reprod. 1988 Oct;39(3):532-5. doi: 10.1095/biolreprod39.3.532.
The effects of weaning and naloxone on concentrations of luteinizing hormone (LH) at 20 days postpartum were examined. March-lambing Finnish Landrace x Southdown ewes (n = 20) were bled via jugular venipuncture at 10-min intervals for 4 h. Naloxone (1 mg/kg bodyweight) was administered i.v. at 60, 120, and 180 min. Treatment groups were suckled (S), weaned on Day 17 (W), suckled plus naloxone (SN), and weaned plus naloxone (WN). Mean concentrations of LH were calculated for 0-60, 70-120, 130-180, and 190-240 min time intervals. Analysis of variance indicated a group effect (p = 0.03) and a group x time interaction (p = 0.02). Concentrations of LH followed a cubic pattern in SN (p = 0.03) and WN (p = 0.08) ewes, whereas LH levels decreased (p less than 0.05) in a pattern consisting of linear and quadratic trends in S and W ewes. Concentrations of LH in S and W ewes were similar at 0-60 and 190-240 min. W ewes had lower (p less than 0.05) concentrations of LH than S ewes at 70-120 and 130-190 min. Further analysis revealed that LH was elevated in SN ewes (p = 0.01) and WN ewes (p = 0.07) at 70-120 min, but was not significantly elevated at 130-180 min. At 190-240 min LH was increased in SN ewes (p = 0.03), but LH levels in WN ewes were similar to those of SN ewes as well as to those of S control ewes.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了产后20天断奶和纳洛酮对促黄体生成素（LH）浓度的影响。在3月产羔的芬兰长白×南丘母羊（n = 20）中，通过颈静脉穿刺每隔10分钟采血4小时。在60、120和180分钟时静脉注射纳洛酮（1 mg/kg体重）。处理组包括哺乳组（S）、在第17天断奶组（W）、哺乳加纳洛酮组（SN）和断奶加纳洛酮组（WN）。计算0 - 60、70 - 120、130 - 180和190 - 240分钟时间间隔内LH的平均浓度。方差分析表明存在组效应（p = 0.03）和组×时间交互作用（p = 0.02）。在SN组（p = 0.03）和WN组（p = 0.08）母羊中，LH浓度呈三次方模式，而在S组和W组母羊中，LH水平呈线性和二次趋势下降（p < 0.05）。在0 - 60和190 - 240分钟时，S组和W组母羊的LH浓度相似。在70 - 120和130 - 190分钟时，W组母羊的LH浓度低于S组母羊（p < 0.05）。进一步分析显示，在70 - 120分钟时，SN组母羊（p = 0.01）和WN组母羊（p = 0.07）的LH升高，但在130 - 180分钟时未显著升高。在190 - 240分钟时，SN组母羊的LH升高（p = 0.03），但WN组母羊的LH水平与SN组母羊以及S组对照母羊相似。（摘要截短于250字）
