Hjemdahl P, Fredholm B B
Acta Physiol Scand. 1976 Sep;98(1):74-9. doi: 10.1111/j.1748-1716.1976.tb10304.x.
Hypercapnic acidosis (pH 7.0) inhibits the lipolytic response of canine subcutaneous adipose tissue to i.v. infused noradrenaline (NA) by 80 per cent or more. The response to sympathetic nerve stimulation, on the other hand, is only reduced by 10-40 per cent during acidosis. The fate of intravenously infused 3H-labelled NA (0.35 ug X kg-1 X min-1 for 30 min) was not significantly altered by acidosis. The rate of disappearance of unmetabolized NA from the arterial plasma after an infusion was the same at pH 7.4 and 7.0 and the calculated increase in circulating NA during infusions was 4 ng/ml at both pH:s. I.v. infusion of Na increases adipose tissue blood flow, an effect which is attenuated by acidosis. There was a significant correlation (p less than 0.001) between adipose tissue blood flow and the lipolytic response at normal pH. Preventing the NA-induced increase in blood flow by constant flow perfusion reduced the lipolytic response at normal pH. The degree of inhibition by acidosis of the lipolytic response to i.v. NA was significantly reduced (from 79 to 56 per cent, p less than 0.05) when the adipose tissue was perfused at constant flow. These data suggest that adipose tissue blood flow is important in determining the lipolytic response to i.v. NA, probably by influencing the delivery of NA to the tissue. The marked inhibition by acidosis of lipolysis due to i.v. infused NA therefore appears to be the combined effect of a direct antilipolytic effect of acidosis and a decreased delivery of NA to the adipose tissue due to the attenuated blood flow response.
高碳酸性酸中毒（pH 7.0）可使犬皮下脂肪组织对静脉输注去甲肾上腺素（NA）的脂解反应抑制80%或更多。另一方面，在酸中毒期间，对交感神经刺激的反应仅降低10 - 40%。酸中毒并未显著改变静脉输注的3H标记NA（0.35μg·kg-1·min-1，持续30分钟）的去向。输注后，动脉血浆中未代谢NA的消失速率在pH 7.4和7.0时相同，且在两种pH值下计算得出的输注期间循环NA的增加量均为4 ng/ml。静脉输注钠可增加脂肪组织血流量，酸中毒可减弱这一效应。在正常pH值时，脂肪组织血流量与脂解反应之间存在显著相关性（p < 0.001）。通过恒流灌注防止NA诱导的血流量增加可降低正常pH值时的脂解反应。当脂肪组织以恒流灌注时，酸中毒对静脉输注NA的脂解反应的抑制程度显著降低（从79%降至56%，p < 0.05）。这些数据表明，脂肪组织血流量在决定对静脉输注NA的脂解反应中很重要，可能是通过影响NA向组织的输送。因此，酸中毒对静脉输注NA引起的脂解的显著抑制似乎是酸中毒直接抗脂解作用和由于血流量反应减弱导致NA向脂肪组织输送减少的综合效应。
