Response of hepatic ornithine decarboxylase and polyamine concentration to surgical stress in the rat: evidence for a permissive effect of catecholamines on glucocorticoid action.

Laparatomy of the rat dramatically induced hepatic ornithine decarboxylase that reached a peak 4 h after the operation. A similar pattern was shown by putrescine concentration. Spermidine was also enhanced, while spermine maintained unchanged. Administration to the animals of either isoproterenol or glucocorticoids (hydrocortisone or dexamethasone) also caused dramatic elevation of liver ornithine decarboxylase. The effect of isoproterenol, but not that of glucocorticoids, was prevented by previous treatment with propranolol. The beta-blockade was unable to prevent the effect of laparatomy on the liver enzyme. This was obtained instead, by depleting the endogenous catecholamines with either alpha-methyl-p-tyrosine or reserpine. Under these conditions, administration of glucocorticoids had no effect on the hepatic enzyme.