Splenic infarcts produced in rats by vasoconstrictor drugs

Investigation of the role of vasoconstriction in the production of infarcts would be facilitated by a model based on a non-essential and readily accessible organ. Therefore, we investigated the effects of intraperitoneal injections of vasoconstrictor drugs on spleen and liver in the rat. Phenylephrine produced infarcts of the spleen regularly and infarcts of the liver occasionally. Epinephrine was also effective in rats that had been pretreated with tilorone. The lesions were caused by local (topical) effects of the drugs. In support of this conclusion, reduced perfusion of the target areas was demonstrated in vasoconstrictor-treated rats given India ink intravenously. In addition, splenic infarcts were produced either by intraperitoneal injection or by direct application of epinephrine to the surgically exposed spleen. On the contrary, splenic infarcts were not produced by injections of epinephrine outside the peritoneal cavity, or by intraperitoneal injections if the spleen had been transposed outside of the cavity beforehand. Thus, we have produced an experimental model of splenic infarcts caused by topical application of vasoconstrictor drugs which is reminiscent of the speckled spleen (Fleckmilz) of human pathology.