The potentiation of capsaicin-induced nociception by ET-1 was abolished by prior i.pl. injection of BQ-123 (ET(A) receptor antagonist, 10 nmol), but unaffected by BQ-788 (ET(B) receptors antagonist, 10 nmol), whereas the enhancement of capsaicin-induced hyperalgesia by ET-1 was attenuated by both antagonists.
After partial sciatic nerve ligation (pSNL), rats displayed allodynia and hyperalgesia, which was associated with increased mRNA and protein expressions of spinal Pax2, NFAT5, and mRNA levels of ET-1 and ETAR, but not ETBR.