Microassay of Bovine Serum and Urinary Myoglobin by Reverse Passive Hemagglutination

Abstract

A sensitive microassay by reverse passive hemagglutination (RPHA) was carried out for the measurement of bovine myoglobin (Mb). Sheep erythrocytes fixed with glutaraldehyde and treated with tannic acid were coated with anti-bovine Mb antibodies purified by affinity chromatography. The RPHA test was done by a microtiter method and minimal detectable Mb levels were 10ng/ml in serum and 2ng/ml in urine. Mb levels of 15 normal calves and 15 normal cows ranged from <10 to 80ng/ml in serum and from <2 to 16ng/ml in urine. Sixteen calves with nutritional myopathy showed markedly increased Mb levels in serum, 640 to 51, 200ng/ml, and in urine, 640 to 256, 000ng/ml. Serum Mb levels in calves recovered from nutritional myopathy decreased to nearly normal ranges within 3 to 5 days. Although each of the 51 cows at the onset of parturient paresis showed high levels of serum Mb ranging from 320 to 20, 480ng/ml, while about 30 per cent of the cows showed normal serum CPK activities. Serum Mb levels in cows recovered from parturient paresis rapidly decreased to the normal levels after 2 to 4 days. Serum Mb in cases slaughtered continued at high levels until the last treatment of parturient paresis. It would be concluded that RPHA method is useful for Mb determination in evaluating the myolytic state of bovine myopathy and for early detection of the disease.