Fig. 7: OT alleviated spontaneous nociceptive behaviors and hyperalgesia in inflammatory pain models via the humoral pathway.
From: Endogenous oxytocin exerts anti-nociceptive and anti-inflammatory effects in rats
Experimental procedures administering CNO after the formalin test (a) and OT receptor (OTR) antagonist treatment (b). c Hind paw either pretreated with Saline or CNO. d Pretreatment with CNO significantly attenuated the swelling caused by 5% formalin (100 µL) injection (n = 11 rats, each). e Licking time was analyzed every 5 min interval for 60 min after the s.c. injection of 5% formalin (100 µL) (n = 5–6 rats, each). **P < 0.01 vs. Saline. f Total licking time was divided into 1st and 2nd phase (n = 5–6 rats, each). **P < 0.01 vs. Saline. g Licking time was analyzed at 5 min interval for 60 min after the s.c. injection of CNO (1 mg kg−1) pretreatment with L-371,257 dissolved in DMSO [10 mg kg−1] for OTR antagonist i.p., Atosiban dissolved in saline [1 μg μL−1] for OTR antagonist i.t., and/or vehicle in the formalin test (n = 6 rats, each). Data are represented as mean ± SEM. **P < 0.01 vs. Vehicle i.p. + Vehicle i.t., #P < 0.05; ##P < 0.01 vs. Vehicle i.p. + OTR antagonist i.t. at the same time point. h Total licking time was divided into 1st and 2nd phase (n = 6 rats, each). **P < 0.01 vs. Vehicle i.p. + Vehicle i.t. i Foot pad thickness was measured at the start and the end of the formalin test and the difference was calculated (n = 6 rats, each). Data are represented as mean ± SEM. **P < 0.01 vs. Vehicle i.p. + Vehicle i.t., #P < 0.05, vs. Vehicle i.p. + OTR antagonist i.t. See also Supplementary Fig. 8.
