Nitric-oxide-dependent activation of pig oocytes: the role of the cGMP-signalling pathway.
Pig oocytes matured in vitro were parthenogenetically activated (78%) after treatment with 2 mM nitric oxide-donor (+/-)-S-nitroso-N-acetylpenicillamine (SNAP) for 24 h. Inhibition of soluble guanylyl cyclase with the specific inhibitors 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or 6-anilino-5,8-quinolinequinone (LY83583) suppressed the SNAP-induced activation in a dose-dependent manner (23% of activated oocytes after treatment with 400 microM ODQ; 12% of activated oocytes after treatment with 40 microM LY83583). 8-Bromo-cyclic guanosine monophosphate (8-Br-cGMP), a phosphodiesterase-resistant analogue of cGMP, enhances the effect of suboptimal doses (0.1 or 0.5 mM) of the NO donor SNAP. DT3, a specific inhibitor of cGMP-dependent protein kinase (PKG, PKG), is also able to inhibit the activation of pig oocytes after NO donor treatment. Involvement of the cGMP-dependent signalling pathway is specific for NO-induced oocyte activation, because both the guanylyl cyclase inhibitor ODQ and the PKG inhibitor DT3 are unable to inhibit activation in oocytes treated with the calcium ionophore A23187. These data indicate that the activation of pig oocytes with an NO donor is cGMP-dependent and that PKG plays an important role in this mode of oocyte activation.
Petr
J
J
Research Institute of Animal Production, Prátelství 815, Prague 10, Czech Republic.
Rajmon
R
R
Chmelíková
E
E
Tománek
M
M
Lánská
V
V
Pribánová
M
M
Jílek
F
F
D000634:Aminoquinolines / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004074:Digitoxin / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D006162:Guanylate Cyclase; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D010069:Oxadiazoles / Q000378:metabolism / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000378:metabolism / Q000494:pharmacology; D011810:Quinoxalines / Q000378:metabolism / Q000494:pharmacology; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D000071756:Soluble Guanylyl Cyclase; D013552:Swine / Q000378:metabolism*
C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D000634:Aminoquinolines; D010069:Oxadiazoles; D047428:Protein Kinase Inhibitors; D011810:Quinoxalines; D018160:Receptors, Cytoplasmic and Nuclear; C110881:S-nitro-N-acetylpenicillamine; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; C041715:6-anilino-5,8-quinolinedione; D004074:Digitoxin; D019001:Nitric Oxide Synthase; D017869:Cyclic GMP-Dependent Protein Kinases; D010727:Phosphoric Diester Hydrolases; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D010396:Penicillamine; D006152:Cyclic GMP