Mårin P, Odén B, Björntorp P
Department of Medicine, Sahlgren's Hospital, University of Goteborg, Sweden.
J Clin Endocrinol Metab. 1995 Jan;80(1):239-43. doi: 10.1210/jcem.80.1.7829619.
Studies on regional differences of adipose tissue metabolism have mainly been performed in vitro. To allow measurements of lipid uptake in vivo in man, radioactive label from [9,10-3H]oleic acid in 80 g orally administered milk fat was measured after 4 h in abdominal and femoral sc adipose tissues in 28 middle-aged, abdominally obese men. Radioactivity was measured in adipose tissue triglycerides extracted from needle biopsies. Lipoprotein lipase (LPL) activity was also measured. Uptake of label in triglycerides and LPL activity were higher (20% and 15%, respectively; P < 0.05) in the abdominal compared to the femoral adipose tissue region. The men were then randomly assigned to three groups, receiving testosterone (T), dihydrotestosterone, or placebo, for 9 months. After 2 months of treatment, the procedure of administration of label was repeated, this time using [U-14C]oleic acid as a marker. Measurements of radioactive label was then performed after 4 h and monthly up to 7 months. Supplementation with T was followed by an inhibited uptake of label in triglycerides (34%; P < 0.05), lower LPL activity (48%; P < 0.05), and a shorter t1/2 (30%; P < 0.05) in the abdominal adipose tissue region compared with the dihydrotestosterone and placebo groups. No significant effect of T on triglyceride uptake, LPL activity, or t1/2 was found in sc femoral adipose tissue. It was concluded that the turnover rate of depot triglycerides is more rapid in abdominal compared to femoral sc adipose tissue in men. Furthermore, T supplementation inhibits triglyceride uptake and LPL activity and causes a more rapid turnover of triglycerides only in the sc abdominal adipose tissue region. These results demonstrate the marked effects of T on adipose tissue metabolism in vivo and suggest that T is an important regulator of the proportion of depot fat mass in central and peripheral adipose tissue in men.
关于脂肪组织代谢区域差异的研究主要是在体外进行的。为了能够在人体中测量体内脂质摄取情况，对28名中年腹型肥胖男性口服80克含[9,10 - 3H]油酸的乳脂肪后4小时，测量其腹部和股部皮下脂肪组织中的放射性标记物。从针吸活检提取的脂肪组织甘油三酯中测量放射性。还测量了脂蛋白脂肪酶（LPL）活性。与股部脂肪组织区域相比，腹部脂肪组织中甘油三酯的标记物摄取和LPL活性更高（分别高20%和15%；P < 0.05）。然后将这些男性随机分为三组，分别接受睾酮（T）、双氢睾酮或安慰剂治疗9个月。治疗2个月后，重复标记物给药过程，这次使用[U - 14C]油酸作为标记物。然后在4小时后以及直至7个月每月测量放射性标记物。与双氢睾酮和安慰剂组相比，补充T后腹部脂肪组织区域甘油三酯中的标记物摄取受到抑制（34%；P < 0.05），LPL活性降低（48%；P < 0.05），半衰期缩短（30%；P < 0.05）。在股部皮下脂肪组织中未发现T对甘油三酯摄取、LPL活性或半衰期有显著影响。得出的结论是，男性腹部皮下脂肪组织中储存甘油三酯的周转率比股部皮下脂肪组织更快。此外，补充T仅在腹部皮下脂肪组织区域抑制甘油三酯摄取和LPL活性，并导致甘油三酯周转更快。这些结果证明了T对体内脂肪组织代谢有显著影响，并表明T是男性中央和外周脂肪组织中储存脂肪量比例的重要调节因子。
