Characterization of adenylyl cyclase stimulated by VIP in rat and mouse peritoneal macrophage membranes.
Vasoactive intestinal peptide (VIP) stimulated adenylyl cyclase activity in rat and mouse peritoneal macrophage membranes. GTP potentiated the stimulatory effect of VIP so that it was routinely included at 10 microM GTP. Other agents like GTP, Gpp(NH)p, GTP-gamma-S, sodium fluoride, and forskolin, at a concentration of 0.1 mM, increased the basal activity of enzyme by 3.1, 5.7, 4.7, 3.6, and 7.8-fold, respectively. The stimulation of adenylyl cyclase by VIP was time, temperature, and membrane concentration dependent. Half-maximal enzyme activation (ED50) was very similar in rat and mouse peritoneal macrophage membranes (1.5 +/- 0.1 nM and 1.0 +/- 0.1 nM, respectively). However, VIP showed more efficacy in mouse macrophages membranes (about 3.1-fold basal values) than that in rat macrophage membranes (about 2.5-fold basal values). The relative potency of several peptides upon stimulation of adenylyl cyclase activity showed the following potency in both species: VIP = PACAP38 = PACAP27 > helodermin > PHI > secretin. On the other hand, a M(r)-45 kDa alpha s subunit of Gs protein was demonstrated by both ADP-ribosylation and immunoblot in mouse and rat peritoneal macrophage membranes. The present results, together other previous, strongly suggest that VIP play an important role in the regulation of macrophage function.
Pozo
D
D
Departmento de Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain.
Segura
J J
JJ
Carrero
I
I
Guijarro
L G
LG
Prieto
J C
JC
Calvo
J R
JR
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002772:Cholera Toxin / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins; D007700:Kinetics; D017737:Macrophages, Peritoneal / Q000201:enzymology*; D051379:Mice; D009243:NAD / Q000378:metabolism; D009479:Neuropeptides / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D051381:Rats; D017208:Rats, Wistar; D012633:Secretin / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
C495402:Adcyap1 protein, mouse; C495403:Adcyap1 protein, rat; D036341:Intercellular Signaling Peptides and Proteins; D009479:Neuropeptides; D010455:Peptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D009243:NAD; D012633:Secretin; D005576:Colforsin; D000246:Adenosine Diphosphate Ribose; D006165:Guanylyl Imidodiphosphate; D014660:Vasoactive Intestinal Peptide; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; C040442:heliodermin; D012969:Sodium Fluoride; D002772:Cholera Toxin; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases