scholarly journals Effects of protein kinase C on parthenogenetic activation of pig oocytes using calcium ionophore or nitric oxide-donor

2008 ◽  
Vol 52 (No. 12) ◽  
pp. 415-422 ◽  
Author(s):  
J. Petr ◽  
E. Chmelíková ◽  
A. Dörflerová ◽  
M. Ješeta ◽  
Z. Kuthanová
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Calcium Ionophore ◽  
Nitric Oxide Donor ◽  
Oocyte Activation ◽  
Parthenogenetic Activation ◽  
Kinase C ◽  
Activation Rate ◽  
Pkc Inhibitors

Porcine oocytes matured <I>in vitr</I>o were activated for parthenogenetic development using either calcium ionophore (50&mu;M for 10 min) or nitric oxide donor SNAP (2mM for 23.5 hours). Protein kinase C (PKC) inhibitors, bisindolylmaleimide I or rottlerin, are able to inhibit parthenogenetic activation induced by calcium ionophore. The rate of activated oocytes decreased from 69% to 2% (<I>P</I> < 0.05) under the effect of bisindolylmaleimide I at a concentration of 0 or 20nM, respectively. The activation rate decreased from 68% to 0% (<I>P</I> < 0.05) under the influence of 0 or 20&mu;M rottlerin, respectively. PKC inhibitors Go6976 or hispidin had no effect on the oocyte activation using calcium ionophore or on oocytes activated by a nitric oxide donor. The activation of oocytes by a nitric oxide donor is not significantly influenced even under the effects of bisindolylmaleimide I or rottlerin. Based on these data we can conclude that the oocyte activation induced by calcium ionophore depends on PKC, especially on PKC-δ. On the other hand, the oocyte activation induced by nitric oxide is independent of the tested isotypes of PKC.

Action of protein kinase C in endothelin-induced contractions in rat aortic rings

1996 ◽  
Vol 271 (1) ◽  
pp. C398-C404 ◽  
Author(s):  
G. K. Oriji ◽  
H. R. Keiser
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Nitric Oxide Release ◽  
Kinase C ◽  
Nitrite Production ◽  
Pkc Inhibitors ◽  
Potent Vasoconstrictor ◽  
Nitrate And Nitrite ◽  
Oxide Synthase

Endothelin (ET) is a potent vasoconstrictor peptide that induces characteristically long-lasting contractions. We used both intact and endothelium-denuded rat aortic rings to investigate the role of protein kinase C (PKC) in ET-induced contractions. ET (10(-9) M) and phorbol 12,13-dibutyrate (PDBu), a PKC activator, produced a gradual and sustained contraction of greater magnitude in denuded aortic rings than in intact rings. When aortic rings were pretreated with graded concentrations of different PKC inhibitors, inhibition of ET-induced contractions began at 10(-9)M and was nearly complete at 10(-3)M, and the reduction was greater in intact than in denuded rings. Pretreatment of aortic rings with PDBu or NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase, potentiated ET-induced contractions. PKC enzyme assay showed activation of PKC in aortic rings that were treated with either ET or PDBu, inhibition after pretreatment with PKC inhibitors, and no change with 4 alpha-phorbol 12,13-didecanoate (PDD), an inactive phorbol ester. ET significantly increased nitrate and nitrite production, which was further increased by pretreatment with PKC inhibitors. PDBu prevented ET-induced nitrate/nitrite production, and PDD had no effect. These results strongly suggest that PKC mediates, in part, ET-induced contractions in rat aortic rings and that an intact endothelium is required for maximum inhibition by PKC inhibitors because PKC stimulated by ET inhibits nitric oxide release.

Involvement of protein kinase C, tyrosine kinases, and Rho kinase in Ca2+ handling of human small arteries

2000 ◽  
Vol 279 (3) ◽  
pp. H1228-H1238 ◽  
Author(s):  
M. Carmen Martínez ◽  
Voahanginirina Randriamboavonjy ◽  
Patrick Ohlmann ◽  
Narcisse Komas ◽  
Juan Duarte ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Signaling Pathways ◽  
Tyrosine Kinases ◽  
Rho Kinase ◽  
Free Medium ◽  
Kinase C ◽  
Intracellular Ca ◽  
Pkc Inhibitors ◽  
Continuous Presence

The mechanisms of Ca2+ handling and sensitization were investigated in human small omental arteries exposed to norepinephrine (NE) and to the thromboxane A2 analog U-46619. Contractions elicited by NE and U-46619 were associated with an increase in intracellular Ca2+ concentration ([Ca2+]i), an increase in Ca2+-independent signaling pathways, or an enhancement of the sensitivity of the myofilaments to Ca2+. The two latter pathways were abolished by protein kinase C (PKC), tyrosine kinase (TK), and Rho-associated protein kinase (ROK) inhibitors. In Ca2+-free medium, both NE and U-46619 elicited an increase in tension that was greatly reduced by PKC inhibitors and abolished by caffeine or ryanodine. After depletion of Ca2+ stores with NE and U-46619 in Ca2+-free medium, addition of CaCl2 in the continuous presence of the agonists produced increases in [Ca2+]i and contractions that were inhibited by nitrendipine and TK inhibitors but not affected by PKC inhibitors. NE and U-46619 induced tyrosine phosphorylation of a 42- or a 58-kDa protein, respectively. These results indicate that the mechanisms leading to contraction elicited by NE and U-46619 in human small omental arteries are composed of Ca2+ release from ryanodine-sensitive stores, Ca2+ influx through nitrendipine-sensitive channels, and Ca2+ sensitization and/or Ca2+-independent pathways. They also show that the TK pathway is involved in the tonic contraction associated with Ca2+ entry, whereas TK, PKC, and ROK mechanisms regulate Ca2+-independent signaling pathways or Ca2+sensitization.

Oxidative stress in diabetes-induced endothelial dysfunction involvement of nitric oxide and protein kinase C

2003 ◽  
Vol 35 (6) ◽  
pp. 683-694 ◽  
Author(s):  
Flavia Pricci ◽  
Gaetano Leto ◽  
Lorena Amadio ◽  
Carla Iacobini ◽  
Samantha Cordone ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Endothelial Dysfunction ◽  
Kinase C

Mechanism of Hepatic Heme Oxygenase-1 Induction by Isoflurane

2006 ◽  
Vol 104 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Alexander Hoetzel ◽  
Daniel Leitz ◽  
Rene Schmidt ◽  
Eva Tritschler ◽  
Inge Bauer ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase A2 ◽  
Heme Oxygenase ◽  
Kupffer Cell ◽  
Cell Function ◽  
Heme Oxygenase 1 ◽  
Gadolinium Chloride ◽  
Kinase C

Background The heme oxygenase pathway represents a major cell and organ protective system in the liver. The authors recently showed that isoflurane and sevoflurane up-regulate the inducible isoform heme oxygenase 1 (HO-1). Because the activating cascade remained unclear, it was the aim of this study to identify the underlying mechanism of this effect. Methods Rats were anesthetized with pentobarbital intravenously or with isoflurane per inhalation (2.3 vol%). Kupffer cell function was inhibited by dexamethasone or gadolinium chloride. Nitric oxide synthases were inhibited by either N(omega)-nitro-L-arginine methyl ester or S-methyl thiourea. N-acetyl-cysteine served as an antioxidant, and diethyldithiocarbamate served as an inhibitor of cytochrome P450 2E1. Protein kinase C and phospholipase A2 were inhibited by chelerythrine or quinacrine, respectively. HO-1 was analyzed in liver tissue by Northern blot, Western blot, immunostaining, and enzymatic activity assay. Results In contrast to pentobarbital, isoflurane induced HO-1 after 4-6 h in hepatocytes in the pericentral region of the liver. The induction was prevented in the presence of dexamethasone (P &lt; 0.05) and gadolinium chloride (P &lt; 0.05). Inhibition of nitric oxide synthases or reactive oxygen intermediates did not affect isoflurane-mediated HO-1 up-regulation. In contrast, chelerythrine (P &lt; 0.05) and quinacrine (P &lt; 0.05) resulted in a blockade of HO-1 induction. Conclusion The up-regulation of HO-1 by isoflurane in the liver is restricted to parenchymal cells and depends on Kupffer cell function. The induction is independent of nitric oxide or reactive oxygen species but does involve protein kinase C and phospholipase A2.

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