Hello all, similar to a few other members of Longecity, I've had a hell of a time with depersonalization/anhedonia. I've read through the several Kappa opioid threads and it seems to be a novel, potent target for these kinds of disorders, however, taking Kappa agonists in hopes of downregulating a notoriously stubborn receptor isn't an attractive idea. Nor is taking research chemicals that don't address the initial upregulation of the receptors in response to stress/social defeat/inflammation. So after hitting that pubmed, I'm curious if any of the following methods seem promising?
Gonadal hormones decrease temporomandibular joint κ-mediated antinociception through a down-regulation in the expression of kappa opioid receptors in the trigeminal ganglia AbstractWe have previously demonstrated that activation of κ-opioid receptor located in the temporomandibular joint (TMJ) of rats induces a significantly greater TMJ antinociception in diestrus females than in proestrus females (higher estradiol serum levels than diestrus) and males. These findings indicate that gonadal hormones decrease TMJ kappa-mediated antinociception. The aim of this study was to investigate some of the mechanisms by which gonadal hormones decrease TMJ kappa-mediated antinociception. Western blot analysis demonstrated a significantly lower κ-opioid receptor expression in the trigeminal ganglia of intact males than in intact and ovariechtomized (OVX) females and orchidectomized (ORX) males. In females, κ-opioid receptor expression in the trigeminal ganglia was significantly lower in proestrus than in diestrus and OVX females. Taken together these findings suggest that gonadal hormones, especially male gonadal hormones, down-regulate κ-opioid receptor expression. Co-application of the NOS inhibitor l-NMMA or the NO-sensitive guanylyl cyclase inhibitor ODQ with the κ-opioid receptor agonist U50,488 blocked TMJ kappa-mediated antinociception in males and females. These findings suggest that antinociception induced by activation of kappa opioid receptors in the TMJ region is mediated by the l-arginine/NO/cGMP pathway in both sexes. Despite the involvement of the l-arginine/NO/cGMP pathway in TMJ kappa-mediated antinociception in both sexes, gonadal hormones do not diminish the activity of this pathway to decrease TMJ kappa-mediated antinociception. Alternatively, they significantly reduce κ-opioid receptor expression in the trigeminal ganglia.
It would make sense that higher male sex hormones, which are downregulated by social defeat, would subsequently downregulate the Kappa Opioid receptors. Theoretically then, megadosing that Icariin should theoretically downregulate Kappa Opioid, although the cGMP effects of Icariin give me pause. The second point about KOR and the L-arginine/NO/cGMP being related is quite interesting, and goes nicely with the following abstract:
Regulation of kappa-opioid receptor mRNA level by cyclic AMP and growth factors in cultured rat glial cells.AbstractThe mRNA of the kappa-opioid receptor (KOR) has been found recently in cultured astrocytes and in microglia. By using RT-PCR and Southern hybridization, we confirmed these observations and, in addition, we observed that KOR mRNA was expressed in oligodendrocytes and in the precursors of astrocytes and oligodendrocytes. KOR mRNA level was the highest in the immature astrocytes and decreased with their maturation. Very few data are available on the regulation of KOR level by extracellular signals. Therefore, we examined the effect of three growth factors known to be present in the adult brain, basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF-BB) and leukemia inhibitory factor (LIF) and of two cyclic AMP (cAMP) generating systems, the cAMP analog, 8-(4-chlorophenylthio)-cAMP and forskolin, on this level. It was found that in astrocytes, KOR mRNA level decreased dramatically under the effect of cAMP and less under the effect of bFGF while it did not change significantly after LIF treatment. In oligodendrocytes, it also decreased with cAMP, but increased under the effect of bFGF and PDGF-BB. In microglia, a decrease was observed with cAMP and lipopolysaccharides (LPS), the most used activators of macrophages. These results shed new evidence on the expression of opioid receptor mRNA in the glial cells of the rat CNS. The regulation of KOR mRNA level under the effect of extracellular signals suggests that opioids take part in dynamic processes in glial cells, possibly related to glial-neuron communication.
So Forskolin is an indirect KOR antagonist? Has anyone taking the CILTEP stack felt an improvement in depersonalization/anhedonia? It would be interesting if someone who's had a positive response to Forskolin/CILTEP and has tried one of the experimental KOR antagonists could compare the effect of the two.
As an aside, blocking Interleukin 1 beta might be something good to try:
Interleukin-1 beta contributes to the upregulation of kappa opioid receptor mrna in dorsal root ganglia in response to peripheral inflammation.AbstractDuring local painful inflammation, axonal transport of opioid receptors from dorsal root ganglia toward the periphery is increased, associated with a higher receptor density and enhanced efficacy of opioid analgesics at the injured site. To examine whether this increase is related to transcription, mRNA of the kappa opioid receptor in lumbar dorsal root ganglia was quantified by real time light cycler polymerase chain reaction. In dorsal root ganglia of naive rats, kappa opioid receptor mRNA expression was three-fold higher than previously shown for delta opioid receptor and two times lower than mu opioid receptor mRNA, respectively. After induction of unilateral paw inflammation by Freund's complete adjuvant, kappa opioid receptor mRNA was significantly upregulated with a peak at 12 h in ipsilateral dorsal root ganglia. This effect could be mimicked by intraplantar injection of the proinflammatory cytokine interleukin-1 beta. Kappa opioid receptor mRNA upregulation lasted longer in interleukin-1 beta-treated rats compared with Freund's complete adjuvant-treated rats. Furthermore, a significant increase in kappa opioid receptor positive neurons was detected by immunohistochemistry 24 h after local injection of Freund's complete adjuvant or interleukin-1 beta. In Freund's complete adjuvant-induced inflammation, kappa opioid receptor upregulation was blocked by treatment with interleukin-1 receptor antagonist without changing the leukocyte infiltration in the paw. In conclusion, kappa opioid receptor mRNA and protein in dorsal root ganglia are upregulated in response to peripheral inflammation. This effect can be mimicked by a single local injection of interleukin-1 beta, and Freund's complete adjuvant-induced upregulation in kappa opioid receptor mRNA and protein can be prevented by treatment with interleukin-1 receptor antagonist. These data suggest that the peripheral production of the proinflammatory cytokine interleukin-1 beta is a specific inducer of kappa opioid receptor expression in the dorsal root ganglia.
Any credence to these ideas? Looking for some feedback before smashing the Icariin/Cordyceps