The effect of thiopentone-sodium anesthesia and surgery, relocation, grouping, and hydrocortisone treatment on the blood levels of cortisol, corticosteroid-binding globulin, and catecholamines in pigs

Eight crossbred, ovariectomized gilts (Swedish Landrace X Swedish Yorkshire X Hampshire), with a mean age of 7.5 mo, were studied during anesthesia and surgery, control-sampling, relocation, and grouping during a period of 3 wk. Acute treatment with a hydrocortisone injection (5 mg, i.v.) was also given. Blood samples were taken frequently (every 10 min) during the intensive part of the experimental days. The blood samples were analyzed for catecholamines (CA), adrenaline (A) and noradrenaline (NA), cortisol, and corticosteroid-binding globulin (CBG). The surgical period with anesthesia and surgery showed significant effects on CA, cortisol, and CBG. The A level increased immediately after the surgery. A biphasic increase in the cortisol level was observed on the day of surgery; the greatest increase was seen when the animals had regained consciousness after surgery but still were drowsy and staggering. The CBG level decreased on the day after the surgery. The study showed that the levels of the analyzed substances were back to normal 2 d after surgery. During relocation and grouping there was a short, significant increase in CA and cortisol levels, whereas the CBG level was not affected. Treatment with hydrocortisone significantly increased the cortisol level, but no change was seen in plasma CA or CBG levels. In conclusion, anesthesia and surgery induced significant effects on the levels of CA, cortisol, and CBG in gilts and the animals needed 2 d to recover before regaining their normal condition. During relocation and a limited grouping period, the significant increases in CA and cortisol levels were of short duration and CBG did not change. The animals returned to their normal condition again a few hours later