Lin M H, Vander Tuig J G, Romsos D R, Akera T, Leveille G A
Am J Physiol. 1979 Sep;237(3):E265-72. doi: 10.1152/ajpendo.1979.237.3.E265.
The possible involvement of Na+,K+-ATPase in the etiology of obesity in the obese (ob/ob) mouse was explored. The number of Na+,K+-ATPase enzyme units in skeletal muscle, liver, and kidneys from 4- and 8-wk-old obese and lean mice was estimated from saturable [3H]ouabain binding to particulate fractions. Neither phenotype nor age altered the Kd value for ouabain binding in these three tissue preparations. The total number of [3H]ouabain binding sites in hindlimb muscles was 35--55% lower in 4- and 8-wk-old obese mice than in their lean counterparts. However, the total number of [3H]ouabain binding sites in liver and kidneys of obese mice was similar to values observed in their lean counterparts. Because it has been suggested that ob/ob mice are hypothyroid, we investigated the response of Na+,K+-ATPase in these mice to thyroid hormone treatment (approximately 5 microgram thyroxine/day for 2 wk). The number of [3H]ouabain binding sites in the three tissues increased in both obese and lean mice injected with this relatively large dose of thyroxine, but the obese mice were 2--3 times more responsive than lean mice.
研究了钠钾ATP酶在肥胖（ob/ob）小鼠肥胖病因学中的可能作用。通过可饱和的[3H]哇巴因与微粒部分的结合，估算了4周龄和8周龄肥胖及瘦小鼠骨骼肌、肝脏和肾脏中钠钾ATP酶的酶单位数量。在这三种组织制剂中，表型和年龄均未改变哇巴因结合的解离常数（Kd）值。4周龄和8周龄肥胖小鼠后肢肌肉中[3H]哇巴因结合位点的总数比瘦小鼠低35%-55%。然而，肥胖小鼠肝脏和肾脏中[3H]哇巴因结合位点的总数与瘦小鼠相似。由于有人提出ob/ob小鼠甲状腺功能减退，我们研究了这些小鼠中钠钾ATP酶对甲状腺激素治疗（约5微克甲状腺素/天，持续2周）的反应。注射这种相对大剂量甲状腺素后，肥胖和瘦小鼠三种组织中[3H]哇巴因结合位点的数量均增加，但肥胖小鼠的反应比瘦小鼠高2-3倍。
