Hayashi S, Wickler S J, Gray S, Horwitz B A
Department of Animal Physiology, University of California, Davis 95616.
Proc Soc Exp Biol Med. 1988 Sep;188(4):435-9. doi: 10.3181/00379727-188-42756.
Oxygen consumption was measured before and during infusion of the catecholamine isoproterenol in age-matched spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) normotensive rats. Mass-independent rates of oxygen consumption of anesthetized 7-week-old rats were similar in the WKY and SHR rats (11.08 +/- 0.74 and 11.33 +/- 0.82 ml O2 min-1 kg-.67, respectively). Catecholamine infusion elicited increased total oxygen consumption in both WKY and SHR animals (15.0 +/- 1.0 and 14.9 +/- 1.2 ml O2 min-1 kg-.67, respectively), and the magnitude of these increases did not significantly differ. To assess whether there were changes in the metabolic state of brown adipose tissue, the major site of catecholamine-induced thermogenesis in rats, enzymes whose activity is proportional to aerobic capacity were assayed in vitro. In both the interscapular and cervical brown fat depots, maximal citrate synthase and maximal HOAD (beta-hydroxyacyl-CoA dehydrogenase) activities were similar in SHR and WKY rats. There were also no significant differences in brown fat protein content, suggesting no differential growth of this tissue in the two rat strains. Our results indicate that the nonshivering thermogenic capacity of the hypertensive SHR rats does not differ from that of the normotensive WKY animals.
在年龄匹配的自发性高血压（SHR）大鼠和Wistar-Kyoto（WKY）正常血压大鼠中，于输注儿茶酚胺异丙肾上腺素之前及期间测量了氧耗量。在WKY和SHR大鼠中，麻醉的7周龄大鼠与质量无关的氧耗率相似（分别为11.08±0.74和11.33±0.82 ml O2 min-1 kg-.67）。儿茶酚胺输注使WKY和SHR动物的总氧耗量均增加（分别为15.0±1.0和14.9±1.2 ml O2 min-1 kg-.67），且这些增加的幅度无显著差异。为评估棕色脂肪组织的代谢状态是否发生变化（棕色脂肪组织是大鼠中儿茶酚胺诱导产热的主要部位），在体外测定了其活性与有氧能力成正比的酶。在肩胛间和颈部棕色脂肪库中，SHR和WKY大鼠的最大柠檬酸合酶和最大HOAD（β-羟酰基辅酶A脱氢酶）活性相似。棕色脂肪蛋白含量也无显著差异，表明这两种大鼠品系中该组织无差异生长。我们的结果表明，高血压SHR大鼠的非寒战产热能力与正常血压WKY动物无异。
