Evaluation of changes in serum lipoprotein and apolipoprotein patterns in cows with ketosis.

OBJECTIVE

To detect changes in serum lipoprotein and apolipoprotein profiles via precipitation and electrophoresis in ketotic cows and in those cows treated with different methods.

METHODS

21 cows with clinical and subclinical ketosis, 7 healthy cows in the early lactation period, and 7 healthy cows in the nonlactation period.

METHODS

Ketotic cows were allocated into 3 groups; the first group was treated with dextrose and dexamethasone, the second group with dextrose and prednisolone, and the third group with dextrose and insulin. The beta and alpha lipoproteins were precipitated with dextran sulfate-magnesium chloride in ketotic cows after treatment and healthy cows in the nonlactation and lactation periods. The serum samples, precipitates, and supernatants were examined via agarose gel electrophoresis for detection of alterations in serum lipoproteins. Subsequently, alterations in serum apolipoproteins were detected via SDS-PAGE of precipitates.

RESULTS

Compared with serum beta and alpha lipoprotein concentrations in healthy cows during nonlactation, those in cows during lactation were higher; however, those in cows with ketosis were lower. The SDS-PAGE analysis of serum beta lipoproteins revealed that apolipoprotein E (approx 36 and 40 kDa) decreased in ketotic cows, in comparison with healthy cows in the nonlactation and lactation periods, but increased after treatment. Decreases in apolipo-protein B (approx 222 kDa), apolipoprotein A-I (19 and 24 kDa), apolipoprotein A-IV (55 kDa), apolipoprotein C-III (8.8 and 10.2 kDa), and albumin (66 kDa) concentrations were detected in ketotic cows, in comparison with the healthy cows in the lactation period.

CONCLUSIONS

Serum lipoprotein and apolipoproteins may routinely be determined via precipitation and electrophoresis in the diagnosis and treatment of ketosis.