Sexual dimorphism in the antinociception mediated by kappa opioid receptors in the rat temporomandibular joint

15d-Prostaglandin J2 Inhibits Inflammatory Hypernociception: Involvement of Peripheral Opioid Receptor

“…Further supporting the antinociceptive action of 15d-PGJ 2 , although it did not affect formalin induced-nociception in cutaneous tissues, our results demonstrated an inhibition of formalin-induced nociception in TMJ. It is well demonstrated that this test has an inflammatory component (Clemente et al, 2004). It is clear that inflammatory conditions can result in hyperalgesia produced by peripheral sensitization of nociceptors and by central sensitization of the nociceptive neurons.…”

“…The nociceptive response score was defined as the cumulative total number of seconds that the animal spent rubbing the orofacial region asymmetrically with the ipsilateral fore or hind paw plus the number of head flinches counted during the observation period as described previously. Results are expressed as the duration time of nociceptive behavior (Clemente et al, 2004). At the conclusion of the experiment, animals were anesthetized by an i.p.…”

Sex differences in the potency of κ opioids and mixed-action opioids administered systemically and at the site of inflammation against capsaicin-induced hyperalgesia in rats

“…To date, only two published studies have examined sex differences in κ opioids using persistent pain models. Clemente et al (2004) reported that local administration of U50,488 was more effective at reducing formalin-induced hyperalgesia in female rats, with the magnitude of this effect being greater during diestrous than proestrous. Similarly, Binder et al (2000) reported that the peripherally active κ-opioid asimadoline was more effective in female rats at reducing Freunds-induced hyperalgesia when tested against a ther- Fig.…”

“…In rats, for example, reports of κ opioids being more potent in males have appeared exclusively in studies utilizing acute pain models and are more likely to occur when complete dose-effect functions are determined. Although there are only two reports in which κ opioids were examined in persistent pain models, in these studies, the κ opioids tested were either more potent in females or equally potent in males and females (Binder et al 2000;Clemente et al 2004).…”

Sex Difference in κ-Opioid Receptor (KOPR)-Mediated Behaviors, Brain Region KOPR Level and KOPR-Mediated Guanosine 5′-O-(3-[35S]Thiotriphosphate) Binding in the Guinea Pig

“…In most studies in rats, mice, and nonhuman primates, selective KOPR agonists produced more antinociceptive responses in males than females in acute pain assays (Rasakham and Liu-Chen, 2011 and references therein). However, in chronic pain models, the direction of sex differences in the effects of KOPR agonists depends on the pain model used (Binder et al, 2000;Clemente et al, 2004;Elliott et al, 2006a,b).…”