Mazelis A G, Larson S, Ginsberg-Fellner F
Department of Pediatrics, Mount Sinai School of Medicine, New York, New York 10029.
Int J Obes. 1987;11(6):561-70.
A number of previous investigations in obese and normal-weight adults suggested a link between (usually) lower than normal erythrocyte Na+-K+ ATPase activity and obesity, although more recent studies have disputed this link. Developmental patterns of ATPase activity in children have not been studied. Infants of diabetic mothers show an increased incidence of macrosomia and such infants are at risk for later development of obesity. These children provide an ideal group to study the link (if any) between this enzyme and obesity, as well as changes in the level of the enzyme which may occur with age and/or the onset of obesity. The Na+-K+ ATPase levels in erythrocytes from 87 normal children and 27 infants of diabetic mothers were therefore studied by an ouabain-binding method. The study populations contained representatives of three ethnic groups (black, Caucasian and Hispanic) and individuals of normal body weight, as well as overweight and obese individuals. The ATPase activities were not correlated with body weight, sex, or age, nor was umbilical cord red cell ATPase correlated with birthweight. Several children who are being followed have shown considerable variation in percentage ideal body weight (IBW); however their ATPase levels have remained unchanged. There were, however, significant differences among the ethnic groups, with Caucasians having the highest values (0.443 +/- 0.012 pmol ouabain bound/10(9) cells). These data demonstrate the importance of matching study groups by race when investigating factors affecting this enzyme. The differences among the ethnic groups suggest a genetic component in the determination of the activity of this enzyme. This link was further investigated in 14 families and revealed considerable heterogeneity within a given ethnic group, with family members generally having similar enzyme activities, thus supporting a genetic basis for the different enzyme levels. Thus erythrocyte Na+-K+ ATPase in childhood is primarily regulated by genetic factors which are generally independent of body weight.
先前针对肥胖和正常体重成年人的多项研究表明，（通常）低于正常水平的红细胞钠钾ATP酶活性与肥胖之间存在联系，不过最近的研究对这种联系提出了质疑。儿童ATP酶活性的发育模式尚未得到研究。患有糖尿病的母亲所生的婴儿出现巨大儿的几率增加，并且这些婴儿日后有肥胖发展的风险。这些儿童为研究这种酶与肥胖之间的联系（如果存在的话）以及该酶水平可能随年龄和/或肥胖症发作而发生的变化提供了一个理想的群体。因此，采用哇巴因结合法对87名正常儿童和27名患有糖尿病的母亲所生婴儿的红细胞中的钠钾ATP酶水平进行了研究。研究人群包括三个种族群体（黑人、白种人和西班牙裔）的代表，以及体重正常、超重和肥胖的个体。ATP酶活性与体重、性别或年龄均无相关性，脐带红细胞ATP酶也与出生体重无关。几名正在接受跟踪研究的儿童在理想体重百分比（IBW）方面表现出相当大的差异；然而他们的ATP酶水平保持不变。不过，不同种族群体之间存在显著差异，白种人的数值最高（0.443±0.012 pmol哇巴因结合/10⁹个细胞）。这些数据表明，在研究影响这种酶的因素时，按种族匹配研究组非常重要。不同种族群体之间的差异表明，在这种酶活性的决定因素中存在遗传成分。在14个家庭中对这种联系进行了进一步研究，结果显示在特定种族群体中存在相当大的异质性，家庭成员的酶活性通常相似，从而支持了不同酶水平的遗传基础。因此，儿童期红细胞钠钾ATP酶主要受遗传因素调节，这些遗传因素通常与体重无关。
