Effect of some monoamine oxidase inhibitors and cyclic-AMP on plasma fibrinogen level of rats.

In vivo administration of short acting or long acting inhibitor of monoamine oxidase elevates plasma fibrinogen level in rats. These inhibitors cannot elevate plasma fibrinogen level in rats pretreated with p-chlorophenyl alanine and alpha-methyl-meta-tyrosine, inhibitors of catecholamine and serotonin formation respectively. However, administration of epinephrine or serotonin under the above experimental condition elevates fibrinogen level indicating rise of biogenic monoamine, even for a short period, is a good stimulus for increase of plasma fibrinogen. Dibutyryl cyclic-AMP (c-AMP) also elevates fibrinogen level and shows additive effect with theophylline or serotonin.