Impaired hemostasis following denervation of the rat spleen.

The possibility that the noradrenergic system might play a role in modulating platelet activation within the spleen was examined. A new microsurgical model for achieving selective denervation of the rat spleen was created. The denervation procedure resulted in a 96% reduction of the norepinephrine content in splenic tissue. One week after splenic denervation, animals were subjected to standardized splenic resection or standardized transection of mesenteric microvessels. The denervation of the spleen was accompanied by a highly significant increase in bleeding time and blood loss at both locations of trauma. Furthermore, platelet function, measured as adenosine diphosphate (ADP)-induced aggregation, decreased significantly after denervation, indicating that platelet aggregation might be modulated by noradrenergic fibres within the spleen.