Cyclosporine counteracts endotoxemia-evoked reductions in blood pressure and cardiac autonomic dysfunction via central sGC/MAPKs signaling in rats.

The immunosuppressant drug cyclosporine A (CSA) improves survivability in endotoxemia and offsets associated loss in vascular reactivity and hypotension. We tested the hypothesis that central phosphoinositide-3-kinase (PI3K)/soluble guanylate cyclase (sGC)/mitogen activated protein kinases (MAPKs) cascade modulates the CSA counteraction of endotoxic hypotension and cardiac autonomic dysfunction. The effects of pharmacologic inhibition of these molecular substrates in central pools on CSA interaction with cardiovascular responses evoked by lipopolysaccharide (LPS) were evaluated in conscious rats. CSA (10mg/kg) reversed the LPS-evoked (i) hypotension and tachycardia, (ii) decreases in time and spectral measures of heart rate variability (HRV), and (iii) increases in serum TNFα and IL-6. These CSA effects disappeared after intracisternal (i.c.) administration of ODQ (sGC inhibitor) but not wortmannin (PI3K inhibitor). When used alone, ODQ or wortmannin abolished the LPS-evoked hypotension and tachycardia, but had no effect on the concomitant reductions in HRV. We also report that the reversal by CSA of LPS hypotension disappeared after treatment with i.c SB203580 (MAPK