Barron J T, Kopp S J
Department of Medicine, Rush Heart Institute, Rush-Presbyterian-St. Luke's Medical Center, Rush Medical College, Chicago, IL 60612.
Biochim Biophys Acta. 1991 Apr 9;1073(3):550-4. doi: 10.1016/0304-4165(91)90229-a.
The activities of phosphorylase b kinase and phosphorylase a phosphatase were determined during the phases of KCl-induced contraction in porcine carotid artery. Phosphorylase b kinase exhibited a biphasic pattern with activity increasing 70% above basal levels during the early phase of active force generation (45 s into contraction) followed by a decline in activity during the phase of steady-state tension maintenance. Phosphorylase a phosphatase was stimulated simultaneously with phosphorylase b kinase, with activity increasing 100% over basal levels at 45 s into contraction, but remaining elevated at 30 min. Incubation of arteries in 0.5 mM palmitate resulted in a 30% increase in basal activity of phosphorylase b kinase and 117% augmentation of basal phosphatase activity, with no further increase in activity of either enzyme with contraction. The results indicate that both the kinase and phosphatase are subject to regulation during contractile activation of the muscle, possibly by similar but not identical mechanisms.
在氯化钾诱导猪颈动脉收缩的各个阶段，测定了磷酸化酶b激酶和磷酸化酶a磷酸酶的活性。磷酸化酶b激酶呈现双相模式，在主动力产生的早期阶段（收缩开始45秒时），其活性比基础水平增加70%，随后在稳态张力维持阶段活性下降。磷酸化酶a磷酸酶与磷酸化酶b激酶同时受到刺激，在收缩开始45秒时，其活性比基础水平增加100%，但在30分钟时仍保持升高。将动脉置于0.5 mM棕榈酸盐中孵育，导致磷酸化酶b激酶的基础活性增加30%，基础磷酸酶活性增加117%，两种酶的活性在收缩时均未进一步增加。结果表明，在肌肉收缩激活过程中，激酶和磷酸酶均受到调节，可能通过相似但不完全相同的机制。
