plays an inhibitory role in platelets. Gambaryan et al claim that they “have never obtained evidence for any ‘stimulatory’ role of sGC in platelets”1page5335 and conclude that “. . . the NO/sGC/cGMP/PKG pathway plays exclusively inhibitory roles in platelets.”1page5336 With due respect, we wish to point out that inability of someone or some groups to see something does not prove its nonexistenc...

Dopamine (DA) in the medial preoptic area (MPOA) provides important facilitative influence on male rat copulation. We have shown that the nitric oxide-cGMP (NO-cGMP) pathway modulates MPOA DA levels and copulation. We have also shown that systemic estradiol (E(2)) maintains neuronal NO synthase (nNOS) immunoreactivity in the MPOA of castrates, as well as relatively normal DA levels. This effect...

Although the nitric oxide/cGMP pathway has many important roles in biology, studies of this system in the mammalian cochlea have focused on the first enzyme in the pathway, nitric oxide synthase (NOS). However, characterization of the NO receptor, soluble guanylate cyclase (sGC), is crucial to determine the cells targeted by NO and to develop rational hypotheses of the function of this pathway ...

In a previous study by our group memory impairment in rats with minimal hepatic encephalopathy (MHE) was associated with the inhibition of the glutamate‑nitric oxide‑cyclic guanosine monophosphate (Glu‑NO‑cGMP) pathway due to elevated dopamine (DA). However, the effects of DA on the Glu‑NO‑cGMP pathway localized in primary cortical astrocytes (PCAs) had not been elucidated in rats with MHE. In ...

Background The heart responds to maladaptive pro-hypertrophic stimuli by stimulating intrinsic signals that contrast and dampen the onset and development of hypertrophy. Cyclic guanosine monophosphate (cGMP) and its downstream effector cGMP kinase I (cGKI) have been suggested to be an important anti-hypertrophic signalling pathway (1). Intracellular levels of cGMP can be raised by the action of...

Epinephrine plays a key role in the control of vasomotor tone; however, the participation of the NO/cGMP pathway in response to beta-adrenoceptor activation remains controversial. To evaluate the involvement of the endothelium in the vascular response to epinephrine, we assessed NO production, endothelial NO synthase phosphorylation, and tissue accumulation of cGMP in the perfused arterial mese...

UNLABELLED The nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) signal pathway plays an important role in anesthetic and analgesic effects. We sought to determine the involvement of inhibition of soluble guanylyl cyclase (sGC) in the anesthetic mechanism and site of action of volatile anesthetics. We examined the effect of intracerebroventricular (ICV) administration of methylene blue (M...

Soluble guanylate cyclase (sGC) is the primary receptor for nitric oxide (NO), which enhances GTP to cGMP conversion by sGC ~200-fold. The second messenger, cGMP, further modulates the activity of kinases and ion channels and ultimately induces smooth muscle relaxation and vasodilation. In cases of endothelial dysfunction, diminished NO production and insufficient output of the NOsGC-cGMP pathw...

The airways of patients with cystic fibrosis (CF) exhibit decreased nitric oxide (NO) concentrations, which might affect airway function. The aim of this study was to determine the effects of NO on ion transport in human airway epithelia. Primary cultures of non-CF and CF bronchial and bronchiolar epithelial cells were exposed to the NO donor sodium nitroprusside (SNP), and bioelectric variable...

Since hyperglycemia is involved in the "aspirin resistance" occurring in diabetes, we aimed at evaluating whether high glucose interferes with the aspirin-induced inhibition of thromboxane synthesis and/or activation of the nitric oxide (NO)/cGMP/cGMP-dependent protein kinase (PKG) pathway in platelets. For this purpose, in platelets from 60 healthy volunteers incubated for 60 min with 5-25 mmo...