Measurement and seasonal variations of black bear adipose lipoprotein lipase activity
Measurement and seasonal variations of black bear adipose lipoprotein lipase activity
复制标题
黑熊脂肪脂蛋白脂肪酶活性的测量和季节变化
DOI：
10.1016/0031-9384(94)00246-2
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发表时间：
1995
影响因子：
2.9
通讯作者：
C. Cook
中科院分区：
文献类型：
--
作者：
D. Herminghuysen;M. Vaughan;R. Pace;G. Bagby;C. Cook
黑熊（Ursus americanus）为脂肪生理学研究提供了一个独特的模型，因为它表现出季节性的体重快速增加和减轻，而代谢率没有明显变化。为了更好地了解该模型中的脂肪循环，我们从 1992 年 10 月 1 日到 1993 年 3 月 31 日期间，每隔大约 20 天，从五只圈养的成年熊身上获取了血浆和臀部脂肪组织。该研究包括每只动物的筑巢前和筑巢期。禁食 12 小时后在预预防期间进行采样。熊在洞穴里时会厌食。测定每个时间点的脂肪 LPL 活性和血浆胰岛素浓度。 Predenning LPL 活性 (4.83 ± 0.64 μmol/h/g) 显着高于 Denning 期间的活性 (1.82 ± 0.65, p < 0.001)。在预产期期间，五只熊中的四只观察到禁食 LPL 活性的双相模式。研究期间空腹胰岛素浓度没有显示出这种变化模式（平均值 = 25.1 ± 1.36 pmol/l；范围 1.1–6.0）。我们没有发现 LPL 活性与胰岛素水平之间存在线性关系的证据 (p = 0.139)。 LPL 活性和胰岛素浓度均与体重变化无关（分别为 p = 0.257 和 p = 0.7104）。我们得出的结论是，可以在黑熊脂肪组织中测量 LPL 活性，并且秋季（预化期）活动显着高于冬季（预化期）的活动。此外，LPL的季节性调节还涉及除胰岛素之外的一些因素。
The black bear (Ursus americanus) provides a unique model for the study of adipose physiology because it exhibits seasonal periods of rapid weight gain and weight loss without marked changes in its metabolic rate. To better understand fat cycling in this model, we obtained plasma and gluteal adipose tissue from five captive adult bears at approximately 20-day intervals from October 1 1992 through March 31 1993. The study included a predenning and denning period for each animal. Sampling during the predenning period followed a 12-h fast. Bears were anorectic while denning. Adipose LPL activities and plasma insulin concentrations were determined for each time point. Predenning LPL activities (4.83 ± 0.64 μmol/h/g) were significantly greater than those seen during the denning period (1.82 ± 0.65, p < 0.001). A biphasic pattern of fasting LPL activity was seen in four of the five bears during the predenning period. Fasting insulin concentrations showed no such pattern of variation during the study period (mean = 25.1 ± 1.36 pmol/l; range 1.1–6.0). We found no evidence of a linear relationship between LPL activity and insulin levels (p = 0.139). Neither LPL activity nor insulin concentrations were related to changes in weight (p = 0.257 and p = 0.7104, respecitively). We conclude that LPL activity can be measured in black bear adipose tissue and that fall (predenning) activities are significantly higher than those seen during the winter (denning period). Furthermore, the seasonal regulation of LPL involves some factor(s) in addition to insulin.