The role of protein kinase C in regulating equine eosinophil adherence and superoxide production.
OBJECTIVE
To determine if protein kinase C (PKC) regulates equine eosinophil function.


METHODS
Blood eosinophils were obtained from healthy ponies.


METHODS
IL-5- and histamine-induced adherence to serum-coated plastic was measured as the eosinophil peroxidase content of adherent cells and serum treated zymosan (STZ)-and IL-5-induced superoxide production by the reduction of cytochrome C. Eosinophil PKC activity was quantitated as the rate of transfer of (32)P from ATP to substrate. The effects of Ro31-8220 (isotype non-selective PKC inhibitor), Go6976 (conventional PKC inhibitor), and rottlerin (PKCdelta inhibitor) were determined by ANOVA and Bonferroni's or Dunnett's test.


RESULTS
Ro31-8220 and Go6976 reduced superoxide production whereas only Go6976 inhibited adherence. Rottlerin inhibited histamine-induced adherence and increased STZ-induced superoxide production. Ro31-8220 and Go6976, but not rottlerin, inhibited PKC activity.


CONCLUSIONS
PKC is involved in regulating equine eosinophil adherence and superoxide production. The role of PKCdelta appears to depend upon the stimulus used and response measured.
Sepulveda
M F
MF
Department of Veterinary Basic Sciences, The Royal Veterinary College, Hawkshead Lane, Hertfordshire, UK.
Greenaway
E C
EC
Avella
M
M
Goode
N T
NT
Cunningham
F M
FM
D000704:Analysis of Variance; D000818:Animals; D002227:Carbazoles / Q000494:pharmacology; D002448:Cell Adhesion; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D047209:Eosinophil Peroxidase; D004804:Eosinophils / Q000737:chemistry / Q000166:cytology* / Q000201:enzymology*; D006632:Histamine / Q000378:metabolism; D006736:Horses; D007211:Indoles / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D015848:Interleukin-5 / Q000378:metabolism; D010969:Plastics; D011493:Protein Kinase C / Q000378:metabolism / Q000502:physiology*; D051745:Protein Kinase C-delta; D034622:RNA Interference; D013481:Superoxides / Q000378:metabolism*; D015054:Zymosan
D002227:Carbazoles; D004791:Enzyme Inhibitors; D007211:Indoles; D015848:Interleukin-5; D010969:Plastics; D013481:Superoxides; C081021:Go 6976; D006632:Histamine; D015054:Zymosan; D047209:Eosinophil Peroxidase; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; C064758:Ro 31-8220