[The effect of halothane anesthesia on the function of the adrenal cortex and some metabolites in the blood plasma of pigs not susceptible to malignant hyperthermia].

The effects were investigated of a 25-minute inhalation of halothane with oxygen on three to four months old pigs of the Large White breed. Symptoms of malignant hyperthermia did not occur. The actual total anesthesia, which causes slight hypoproteinemia, hypoglycemia and hypocholesterolemia without significant changes in the content of non-esterified fatty acids (NEFA) and urea, induced only a slight increase of circulating 11-hydroxycorticosteroids (11-OHCS). The combination of anesthesia with castration of gilts or barrows significantly increased the concentration of 11-OHCS but did not reach the level recorded after the application of ACTH. The higher levels of 11-OHCS were accompanied by higher concentrations of NEFA and glucose. The treatment of the animals lasting half an hour prior to inhalation of halothane at maximum doses or one hour in the control unanesthetized pigs produced an effect, mainly on the 11-OHCS concentration and on the activity of creatine kinase in the plasma. The results indicate that the adrenocortical response to the effect of halothane is not stronger than the response to simple handling connected with excitement and muscular activity of the animals. Therefore there is no reason of considering halothane anesthesia as a factor causing great stress and pigs which in its course do not respond with malignant hyperthermia as animals insensitive to stress. The aptness of denotation of clinical manifestations of genetically defective muscles in pigs is discussed.