title: Effects of 5-hydroxytryptamine, cyclic AMP, AMP, and fructose 2,6-bisphosphate on phosphofructokinase activity in Hymenolepis diminuta.
abstract: 1. 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.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology*; D005210:Fasciola hepatica / Q000201:enzymology; D005635:Fructosediphosphates / Q000494:pharmacology*; D006598:Hexosediphosphates / Q000494:pharmacology*; D006926:Hymenolepis / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000494:pharmacology*; D013045:Species Specificity
chemical_list: D005635:Fructosediphosphates; D006598:Hexosediphosphates; D012701:Serotonin; D000249:Adenosine Monophosphate; C027652:fructose 2,6-diphosphate; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D015056:1-Methyl-3-isobutylxanthine