Cebulj-Kadunc N, Kosec M, Cestnik V
Institute of Physiology, Pharmacology and Toxicology, Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia.
Reprod Domest Anim. 2009 Feb;44(1):1-5. doi: 10.1111/j.1439-0531.2007.00963.x. Epub 2008 Apr 7.
To determine seasonal changes in circulating leptin concentrations, as well as leptin fluctuations in various patterns of seasonal ovarian activity, blood samples were taken in 107 Lipizzan fillies aged 1-4 years over the whole year from January to December. Serum concentrations were measured in samples obtained once a month (leptin) or twice a month (progesterone), and evaluated with respect to the age of animals (yearlings, 2-, 3- and 4-year olds) and the pattern of ovarian activity (anoestrous, seasonal cycle, prolonged cyclicity, continuous cyclicity). The mean and monthly leptin concentrations in 3- and 4-year olds were significantly higher than in yearlings and 2-year olds (p < 0.001). Circulating leptin levels in 3- and 4-year olds increased significantly in summer, to peak in August and then decline significantly (p < 0.001) in autumn. The fluctuations in younger fillies were less evident. The highest mean serum leptin concentrations were observed in fillies exhibiting continuous cyclicity and the lowest in those, exhibiting seasonal cyclicity (p < 0.001). In anoestrous fillies, leptin concentrations were lower than in fillies with prolonged or continuous cyclicity but higher than in fillies with seasonal cyclic activity (p > 0.05).
为了确定循环瘦素浓度的季节性变化以及不同季节性卵巢活动模式下瘦素的波动情况，从1月至12月全年采集了107匹1 - 4岁利皮扎马驹的血样。每月（瘦素）或每两个月（孕酮）采集一次样本并测量血清浓度，并根据动物年龄（一岁驹、2岁、3岁和4岁）和卵巢活动模式（乏情期、季节性周期、延长周期、连续周期）进行评估。3岁和4岁马驹的平均瘦素浓度和每月瘦素浓度显著高于一岁驹和2岁马驹（p < 0.001）。3岁和4岁马驹的循环瘦素水平在夏季显著升高，8月达到峰值，然后在秋季显著下降（p < 0.001）。年轻马驹的波动不太明显。在表现出连续周期的马驹中观察到最高的平均血清瘦素浓度，而在表现出季节性周期的马驹中最低（p < 0.001）。在乏情期马驹中，瘦素浓度低于具有延长或连续周期的马驹，但高于具有季节性周期活动的马驹（p > 0.05）。
