RESERPINE-INDUCED INCREASES IN NEUROPEPTIDE-Y MESSENGER-RNA OF GUINEA-PIG SYMPATHETIC-GANGLIA USING IN-SITU HYBRIDIZATION

Background: Neuropeptide Y (NPY) is synthesized in sympathetic ganglia by specific mRNA, to which rat probes are currently available. In the rat model, reserpine treatment increases NPY mRNA through a mechanism involving enhanced preganglionic activity. Probes for NPY mRNA have b een used exclusively in rat models. In this study, we assessed whether a rat NPY cRNA probe could be used to index reserpine-induced changes in NPY mRNA levels of sympathetic ganglia in the guinea pig. Methods: Guinea pigs were given vehicle or reserpine pretreatment. In situ hyb ridization for NPY mRNA was done on the superior cervical and stellate ganglia of four control and four reserpine-treated rats. Autoradiogra phic density was digitized using an automated image analysis system. R esults: Following in situ hybridization of tissue sections, autoradiog raphic density of specific NPY mRNA binding was evident in nerve cell bodies in the superior cervical and stellate ganglia. Reserpine pretre atment was associated with an increase in NPY mRNA levels in both type s of ganglia. Conclusion: These results indicate that reserpine treatm ent in the guinea pig produces increased neuronal NPY mRNA levels. The study also showed that rat NPY cRNA probe can be used to quantify alt erations in NPY mRNA levels in the guinea pig. (C) 1996 Wiley-Liss, In c.