Adenylate cyclase activity from Hirudo medicinalis segmental ganglia: modulation by temperature and Mg2+ ions.
The basal, serotonin- and fluoride-stimulated activities of homogenate preparations from Hirudo medicinalis segmental ganglia increase with incubation temperature, reaching a maximum at 35 degrees C. Both basal and fluoride-stimulated activities yield linear Arrhenius plots, whereas serotonin-enhanced activity shows a break at 25 degrees C. Increasing Mg2+ concentrations stimulate the adenylate cyclase both in the absence and in the presence of serotonin. The affinity of the enzymatic system for the cation is unaffected by the amine.
Ferretti
M E
ME
Institute of General Physiology, University of Ferrara, Italy.
Buzzi
M
M
Pareschi
M C
MC
Cavallaro
R
R
Campi
A L
AL
Biondi
C
C
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D005459:Fluorides / Q000494:pharmacology; D017952:Ganglia, Invertebrate / Q000201:enzymology*; D007865:Leeches / Q000201:enzymology*; D008274:Magnesium / Q000494:pharmacology*; D012701:Serotonin / Q000494:pharmacology; D013696:Temperature
D012701:Serotonin; D000262:Adenylyl Cyclases; D008274:Magnesium; D005459:Fluorides