Relationships between concentrations of biological variables in eye fluids and blood after exercise in Lidia cattle

Abstract

Lidia cattle are a heterogeneous Iberian cattle population known for its natural aggressiveness and resistance to traditional handling procedures making in vivo blood sampling and biological fluid collections extremely difficult. Blood variables are influenced by physical exertion and stressful situations; consequently, post-mortem blood analysis does not reflect basal concentrations for this species. Nevertheless, ocular fluids (aqueous and vitreous humour) maintain their stable composition after death and maybe could be used to estimate ante-mortem blood concentrations. So, 15 bulls which had fought (for 15-20 minutes) and, subsequently after death, blood, aqueous and vitreous humour were sampled. Total protein, albumin, triglycerides, uric acid, urea, AST, ALT, GGT, AP, CK, LDH, cholesterol, creatinine, glucose and lactate were measured. Statistical analysis and correlation coefficients between the three fluids were carried out. All variables showed high plasma concentrations of glucose, uric acid, LDH and CK, compared with normal bovine concentrations. Apart from urea, all plasma concentrations were greater than those found in ocular fluids. The measured enzymes activities were higher in the vitreous than in the aqueous humour, but only marked differences in uric acid, lactate, AP and AST were found. There was a significant correlation between creatinine in the plasma and aqueous humour, and between albumin and GGT in the plasma and vitreous humour. Glucose, creatinine and urea exhibit a high correlation between ocular fluids. All plasma concentrations were clearly modified, however ocular fluids do not seem affected, thus establishing important correlations between the blood and intraocular fluids.