Interferon and 2',5'-oligo(A) synthetase activities in serum and blood mononuclear leukocytes of cattle after injection of bovine interferon-alpha 1.
Cell extracts that were prepared from blood mononuclear leukocytes from 66 samples obtained from 6 clinically normal calves contained mean 2',5'-oligoadenylate (2',5'-oligo[A]) synthetase activity sufficient to synthesize 186 +/- 82 pmol of 2',5'-oligo(A)/h/10(6) cells. Calves had no measurable serum interferon (IFN) activity. Five calves were given IM injections of 10(4), 10(5), 5 x 10(5), 10(6), and 10(7) U of bovine IFN-alpha 1/kg of body weight at 2-week intervals. Five dosing sequences were used with a 5 x 5 Latin square design so that each calf received each dose once. Activity of 2',5'-oligo(A) synthetase increased at 24 hours in response to all dosages of IFN and then declined following first-order kinetics, with an apparent half-life (t1/2) of 2.1 +/- 0.5 days. The area under the concentration-time curve for 2',5'-oligo(A) synthetase increased with dose of IFN more rapidly than did peak response. Serum IFN that was measured at 1-day intervals following administration of IFN was consistently measurable only at dosages above 10(6) U of IFN/kg. The t1/2 for circulating IFN was 12.4 +/- 1.0 hours. Over all dosages, increases in 2',5'-oligo(A) synthetase activity were measurable for 3.5 days longer than were increases in IFN following IM injection of IFN. None of the calves developed detectable anti-IFN antibodies.
Department of Veterinary Parasitology, College of Veterinary Medicine, Oklahoma State University, Stillwater 74078.
L J
LJ
Perino
E C
EC
Short
L J
LJ
Burge
D A
DA
Winter
R W
RW
Fulton
D015088:2',5'-Oligoadenylate Synthetase / Q000096:biosynthesis* / Q000097:blood; D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D015415:Biomarkers / Q000097:blood; D002417:Cattle / Q000097:blood*; D004790:Enzyme Induction / Q000187:drug effects; D007273:Injections, Intramuscular / Q000662:veterinary; D007370:Interferon Type I / Q000008:administration & dosage / Q000494:pharmacology; D007372:Interferons / Q000097:blood* / Q000494:pharmacology; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000201:enzymology / Q000378:metabolism*; D013997:Time Factors
D000914:Antibodies, Viral; D015415:Biomarkers; D007370:Interferon Type I; D007372:Interferons; D015088:2',5'-Oligoadenylate Synthetase