Determination of porcine blood creatine kinase by firefly luciferase.

The use of the creatine kinase-luciferase (CK-L) coupled reaction for porcine blood CK determination was studied. Adenosine triphosphate produced by CK is reacted with firefly L light-producing system. The method permits determination of CK in blood as opposed to traditional methods which require plasma or serum. The luciferase procedure was applied to nine barrows each of purebred Pietrain and Yorkshire (Y)Minnesota No. 1 (M)-Pietrain (P) breeding [Yx M(PX M)]. Pietrain pigs exhibited higher (P<.05) ear-blood CK after transportation at 83 kg live weight, but not after exercise at an earlier age (40 kg live weight). Pietrain pigs exceeded YXM(PXM) pigs for longissimus (P<.01) and trapezius (P<.05) muscle pH decline rates, longissimus area (P<.01), ham plus loin percentage (P<.01), and percentage of four lean cuts (P<.01). YXM(PXM) pigs exceeded Pietrains for longissimus subjective color, morphology and marbling (all P< .01)and backfat thickness (P<.05). Intraclass correlation coefficients between blood CK following transportation stress and longissimus pH (20 min postmortem) were significant (P<.05) for Pietrain (r=--.67) and Y• M(PX M) pigs (r=-.79). Highly significant (P<.01)correlation coefficients were noted between serum CK, as determined by the Rosalki procedure, and blood CK, as determined by CK-L for Pietrain (r=.93) and for Yx M(PX M) pigs (r=.99). (