Differing calcium requirements for regulatory effects of ATP, ATP gamma S and adenosine on O2.- responses of human neutrophils.
In formyl peptide stimulated human neutrophils the enhancement of O2.- responses by ATP and ATP S requires extracellular calcium. In contrast, the inhibitory effects of adenosine are independent of a calcium requirement. Rates of O2.- generation are not affected by these adenine compounds. Rather, ATP and ATP S cause a sustained period of generation whereas adenosine causes an abrupt early termination of the O2- response. The differing calcium requirements for regulatory effects of adenine compounds on O2.- responses of stimulated neutrophils suggests that ATP (or ATP gamma S) and adenosine may exert their effects at different points in the pathway of signal transduction events.
Ward
P A
PA
University of Michigan Medical School, Department of Pathology, Ann Arbor 48109.
Cunningham
T W
TW
Walker
B A
BA
Johnson
K J
KJ
D000241:Adenosine / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology*; D006801:Humans; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D013481:Superoxides / Q000097:blood*
D013481:Superoxides; C022571:adenosine 5'-O-(3-thiotriphosphate); D009240:N-Formylmethionine Leucyl-Phenylalanine; D000255:Adenosine Triphosphate; D000241:Adenosine; D002118:Calcium