5-羟色胺、环磷酸腺苷、腺苷一磷酸及果糖2,6-二磷酸对微小膜壳绦虫中磷酸果糖激酶活性的影响

Effects of 5-hydroxytryptamine, cyclic AMP, AMP, and fructose 2,6-bisphosphate on phosphofructokinase activity in Hymenolepis diminuta.

作者信息

Sangster N C, Mettrick D F

机构信息

Department of Zoology, University of Toronto, Ontario, Canada.

出版信息

Comp Biochem Physiol B. 1987;88(1):317-21. doi: 10.1016/0305-0491(87)90122-2.

DOI:10.1016/0305-0491(87)90122-2

Abstract

5-HT (10(-4) M) had no effect on the activity of phosphofructokinase in Hymenolepis diminuta. Concentrations of ATP above 33 microM inhibited PFK activity; AMP and cyclic AMP relieved this inhibition. 2. Local levels of cyclic AMP may be indirectly modulated by NaF, guanylyl imidophosphate, or 5-HT in the presence of GTP, which stimulates adenylyl cyclase activity x2 in H. diminuta homogenates. 3. Fructose 2,6-bisphosphate (F2BP), a physiological regulator of PFK activity in rat liver, also relieved ATP-induced inhibition of PFK. F2BP was present in supernatants from the worms at about 20 mumol/g wet wt. 4. 5-HT may cause an increase in the rate of glycolysis in H. diminuta by elevating either cyclic AMP and/or AMP levels; these nucleotides can in turn increase PFK activity.

摘要

5-羟色胺（10⁻⁴ M）对微小膜壳绦虫中的磷酸果糖激酶活性没有影响。ATP浓度高于33微摩尔时会抑制磷酸果糖激酶活性；AMP和环磷酸腺苷可缓解这种抑制作用。2. 在存在GTP的情况下，NaF、鸟苷酰亚胺磷酸或5-羟色胺可能间接调节环磷酸腺苷的局部水平，GTP可使微小膜壳绦虫匀浆中的腺苷酸环化酶活性提高两倍。3. 果糖2,6-二磷酸（F2BP）是大鼠肝脏中磷酸果糖激酶活性的生理调节剂，也可缓解ATP对磷酸果糖激酶的抑制作用。蠕虫上清液中F2BP的含量约为20微摩尔/克湿重。4. 5-羟色胺可能通过提高环磷酸腺苷和/或AMP水平来增加微小膜壳绦虫中的糖酵解速率；这些核苷酸反过来又可增加磷酸果糖激酶的活性。