URINARY-EXCRETION OF CATECHOLAMINES, CORTISOL AND THEIR METABOLITES IN MEISHAN AND LARGE WHITE SOWS - VALIDATION AS A NONINVASIVE AND INTEGRATIVE ASSESSMENT OF ADRENOCORTICAL AND SYMPATHOADRENAL AXIS ACTIVITY

Urinary free corticoids (cortisol and cortisone), catecholamines (nore pinephrine or NE, epinephrine or E, dopamine or DA, and their O-methox ylated metabolites) as well as creatinine (Cr) were analysed in 42 spo ntaneously voided urine samples from Large White (LW, n = 20), Meishan (MS, n = 6), and LW x MS (F1, n = 16) lactating sows. The cortisol co ncentration in the urine of MS (28.1 pg/mu g Cr) was five-fold greater than that of LW sows (6.2 pg/mu g Cr, P < 10(-4)). FI were intermedia te (12.0 pg/mu g Cr). Mean cortisone concentration was also larger in MS (13.5 pg/mu g Cr) compared to LW (7.1 pg/mu g Cr, P < 0.01). Althou gh the differences were less pronounced, the concentrations of the cat echolamines were also greater in MS than in LW sows (norepinephrine: 2 5.4 versus 5.9 pg/mu g Cr, epinephrine: 8.7 versus 2.8 pg/mu g Cr and dopamine: 59.2 versus 17.8 pg/mu g Cr, P < 10(-4)). These results conf irmed the hypercortisolism state of MS pigs previously shown by plasma cortisol assay and supported the hypothesis that the sympathetic nerv ous system is hyperactive in this breed. These urinary investigations may offer possible applications for the assessment of chronic stress. (C) Inra/Elsevier, Paris.