Effects of insulin on plasma fibrinogen levels in rats submitted to tissue injury or ACTH administration

The effect of epinephrine and serotonin on hepatic poly(A)+ RNA synthesis

In vivo administration of epinephrine or serotonin has been shown to stimulate the incorporation of 14C-orotic acid into Poly(A)+ RNA. However, only epinephrine and not serotonin could stimulate DNA dependent RNA polymerase activity of isolated hepatic nuclei in in vitro experiments.

Effects of the administration of progesterone and adrenal medullectomy on the plasma fibrinogen levels in rats with surgical injury (laparotomy)

The probable rôle played by the adrenal medulla in the decrease of plasma fibrinogen due to the administration of progesterone (0.5 mg kg-1 day-1 during 72 h) in rats submitted to surgical injury (laparotomy) was studied. The results obtained lead to assume that the decrease of plasma fibrinogen observed in laparotomized rats injected with progesterone is indirectly produced through inhibition of the adrenal medulla. The action of progesterone on the plasma fibrinogen would be a pharmacological effect of the drug, since in doses of 0.10 mg kg-1 day-1 the decrease of the fibrinogen is not observed in laparotomized rats. The administration of progesterone in non injured rats does not modify the plasma fibrinogen as compared to the group of non injected rats.

Effects of epinephrine on plasma fibrinogen levels in rats submitted to tissue injury

Tissue injury (laparotomy) produces an increase in plasma fibrinogen. This increase is inhibited by the removal of the adrenal medulla, but injection of epinephrine in laparotomized-medullectomized rats returns fibrinogen levels to values similar to those observed in only laparotomized rats. Epinephrine administration to laparotomized rats increases the fibrinogen compared with the group of laparotomized rats without treatment, but epinephrine by itself does not modify plasma fibrinogen levels in uninjured rats. Epinephrine is apparently responsible for the increase of plasma fibrinogen in rats subjected to tissue injury, probably through beta adrenergic stimulation.