OPRL1 and Sepsis: Only one study has previously utilised the selective NOP antagonist [Nphe1, Arg14,Lys15] N/OFQ-NH2 (UFP-101) [20] during sepsis: in rats, Carvalho et al. demonstrated that 0.03 mg kg-1 UFP-101 improved survival rates from approximately 30% to 65%.