Thanks for the find. So from quickly scanning through it DMT binds to the sigma-1 receptor, but opiates do not. I find this odd as the anesthetic effects of DMT are so powerful, more powerful than any opiate I have taken. It must block pain receptors?

What cells are sigma 1 receptors expressed in? Is it only neuronal tissue? If so any information on where they are localized.

All this is suggesting to me that dmt's effects like the effects of most drugs are mediated by a few different receptors. Would be cool to see what receptors mediate what response with in vivo selective antagonist studies.

they say lung, adrenals, pancreas...interestingly, the same tissues INMT is expressed

No need to put family in parenthesis

Sigma receptors are expressed through-out the entire body. They are found in very high levels through-out most CNS areas and the periphery. Also many many diverse agents (endogenous and exogenous) bind to sigma receptors. Literally it may be easier to list what doesn't bind to sigma-1...., not really but you know what I mean it is notoriously promiscuous. Regarding distribution sig-1 has a "slightly" more limited distribution than sig-2 but is still widely expressed. Highest levels are found in the cerebellum and motor association regions. It is likely that sigma receptors play a key role in cellular physiology rather than as neurotransmitter receptors involved in rapid information processing.