Harmon C S, Masser M R, Phizackerley P J
J Invest Dermatol. 1986 Jan;86(1):69-73. doi: 10.1111/1523-1747.ep12283850.
Pedicled skin flaps in the pig have been used to investigate the effects of 3-h ischemia and reperfusion on the epidermal metabolism of glycogen and glucose. Epidermal glycogen content fell steadily at a rate of about 1.2 mumol of glucose-equivalents per g wet weight per h whereas the rate of glucose consumption declined from 1.8 mumol per g wet weight during the first hour to about 0.25 mumol per g wet weight in the third hour. During ischemia the proportion of glycogen synthase in the I form increased progressively from an initial value of about 8% to about 70%, but the proportion of phosphorylase in the a form decreased only in the third hour of ischemia. The concentration of ATP decreased and ADP and AMP increased but the total pool of epidermal adenine nucleotides was not depleted. On reperfusion, these changes were reversed and normal epidermal concentrations of glucose and adenine nucleotides were restored within 30 min and remained stable thereafter. The resynthesis of glycogen proceeded at a steady rate of about 1 mumol per h per g wet weight and the phosphorylation state of both glycogen synthase and phosphorylase approached normal values after 3 h. It is concluded that epidermal glycogenolysis in ischemia is, at least in part, a consequence of activation of phosphorylase b by AMP, and that glycogen resynthesis on reperfusion is promoted by the ischemic activation of glycogen synthase.
猪的带蒂皮瓣已被用于研究3小时缺血和再灌注对表皮糖原和葡萄糖代谢的影响。表皮糖原含量以每克湿重每小时约1.2微摩尔葡萄糖当量的速率稳步下降，而葡萄糖消耗速率从第一小时的每克湿重1.8微摩尔降至第三小时的每克湿重约0.25微摩尔。在缺血期间，I型糖原合酶的比例从初始值约8%逐渐增加到约70%，但a型磷酸化酶的比例仅在缺血第三小时下降。ATP浓度降低，ADP和AMP增加，但表皮腺嘌呤核苷酸的总量未耗尽。再灌注时，这些变化逆转，表皮葡萄糖和腺嘌呤核苷酸浓度在30分钟内恢复正常，并在此后保持稳定。糖原的重新合成以每克湿重每小时约1微摩尔的稳定速率进行，糖原合酶和磷酸化酶的磷酸化状态在3小时后接近正常值。结论是，缺血时表皮糖原分解至少部分是AMP激活磷酸化酶b的结果，再灌注时糖原的重新合成是由缺血激活糖原合酶促进的。
