Involvement of rostral ventromedullar neuronal structures in nitric oxide modulation of central chemosensitive drive

Surface perfusion of the rostral ventromedullar cerebral subdivisions with artificial cerebrospinal fluid containing exogenous NO donor sodium nitroprusside (0.1 mM) increased the discharge rate of the phrenic nerve and potentiated the response of the respiratory center to hypercapnia in narcotized mature rats. The latter reaction was prevented by blockage of NO-synthase in rostral ventromedullar neural structures with N-nitro-L-arginine methyl ester (L-NAME, 0.3 mM). It was hypothesized that rostral ventromedullar neural structures are involved in modulatory action of NO on central chemosensitive drive.