Figure 3
S-nitrosocysteine (CysNO) mimics the effects of GSNO in modulating GPCR signaling, whereas sodium nitroprusside (SNP) and 8-bromo cyclic GMP (8Br-cGMP) do not. [35S]GTPγS autoradiography was conducted using a 3-step protocol with DPCPX (10-6 M) present throughout steps 2 and 3, as detailed in the Methods section. Where indicated, CysNO (1 mM), SNP (0.5 mM), or 8Br-cGMP (0.25 mM) were present for 60 min during the GDP loading (step 2). Carbachol (10-4 M), 2MeSADP (10-6 M), or LPA (5 × 10-5 M in 0.1% fatty acid free BSA) were present in step 3. Note amplification of CCh-stimulated G protein activity by CySNO, most evident at this coronal plane in the cerebral cortex (Cx), the thalamus (Thal), including the superficial gray layer of the superior colliculus (SuG). Note also CysNO-dependent attenuation of 2MeSADP- and LPA-stimulated responses, most evident in the corpus callosum (cc) and the fimbria of the hippocampus (fi). Scale bar = 2 mm. For quantitative data on selected brain regions, see Supplementary Table 1 in additional file 1.