AFAIK they are indeed sensitive, but before toady knew better, he just used to toss his pods by the handful into a pan, boil it up with a couple of Amanita muscaria caps (cured and dried to detoxify them of course), and drank the resulting abominably stinking brew with a load of sugar and a held nose.
Gods...that stench...there is nothing quite like it. Turns his stomach just thinking about it, most abominable, revolting stench he can bring to mind. Makes chlorine bleach, chloroform, putrescine and mercaptans smell like bloody candy by comparison

He can't wait to give this a shot (pun intended). Needs to get all that poppy seed planted on some nice, remote waste ground. NH3SO4, plus some added potassium phosphate? any good as a fert, jon?
Back on track...
6-MAM and heroin have interesting pharmacological properties. There has been some relatively recent search for the receptor(s) involved, as it appears that 6-MAM in particular, and H (unsure if H has direct affinity for this target or if its simply acting as a prodrug for 6-MAM), the crosstolerance to morphine is incomplete (which might well explain the relatively limited popularity of opioid maintenance/detox facilities which use other opioids, compared to those which provide addicts with limited quantities of pure pharmaceutical diamorphine in injectable format)
Toady has been looking into this particular target of late in the context of his preliminary investigations into iodobenzoylnaltrexamide, IBnTXA acts as a splice-variant specific agonist at a post-translationally modified splice variant of hMOR1, derived from exon-1. Its a truncated 6-transmembrane GCPR with a hacked-down C terminus IIRC (Could bee wrong, and it bee the N-terminus but don't think so)
This seems to prevent the shift between Gi/Go coupling to (GalphaS?) in the case of allodynic pain (neuropathy, which as toady can testify, courtesy of some unsuccessful surgical intervention that left him with probably permanent nerve damage), and Gbetagamma, as the last few 500-kilobase or so of hMOR1 appears to act as a regulatory site, conferring different affinity/efficacy for opioid peptides vs alkaloid ligands (sans, IIRC, actually changing selectivity for the ligands in question) and IIRC modulating coupling of the different G-proteins with their effectors on the intracellular side of things), which, as tolerance progresses, there is a shift in G-protein coupling thus converting a lot of the previous inhibitory signalling, GABAaR suppression of inhibition etc. to favouring the activation of a population of excitatory Mu-ORs (possible that this might explain a lack of euphoria or reinforcement seen with iodobenzoylnaltrexamide? that is, sensitization of MORs and inducement of DA release in the nucleus accumbens that contributes in regular opioids to conditioned place preference, reinforcement, addiction, and that euphoria we bees all know and love from our poppy flower honey?
In addi(c

)tion, Toadface has a quick question. He isn't sure from context during his reading weather the GABAergic suppression of inhibition referred to, is meant to mean, in this specific context, suppressing the inhibition of GABAaRs themselves, leading to more GABAergic activity or suppressing the inhibition of; as is usually meant by 'suppression of inhibition'. GABAaR-mediated inhibitory signalling, leading to DA release* and greater release of other neurotransmitters besides. Could anyone clarify this for him perchance?
*this happens with cannabinoid CB1 agonists, despite the atypical retrograde signalling mechanism of CB1 agonism, activating presynaptic CB1Rs via endogenous cannabinoid ligands of various kinds released postsynaptically which then amongst other actions on other receptors and voltage-gated ion channels of this that and t'other flavor, this suppression of suppression turning up the volume controls on DA release, etc. etc.
In exon-1 -/- mice, they lost responsivity to morphine, and DAMGO (potent MOR1/MOR2 opioid agonist peptide) but retained it to M6G
Proc Natl Acad Sci U S A. 2011 Dec 6;108(49):19778-83. doi: 10.1073/pnas.1115231108.
Truncated G protein-coupled mu opioid receptor MOR-1 splice variants are targets for highly potent opioid analgesics lacking side effects. iodobenzoylnaltrexamide itself appears to possibly not possess a huge amount of euphoria, if its euphorigenic
h ttp://ww w. ncbi.nlm.nih.gov/pubmed/22106286?dopt=Abstract
(free full text)
h ttp://ww w.ncbi.nlm.nih.gov/pmc/articles/PMC3477067/ (full, free)
J Mol Signal. 2012; 7: 13.
doi: 10.1186/1750-2187-7-13
PMCID: PMC3477067
The roles played by highly truncated splice variants of G protein-coupled receptors
PLoS One. 2008 Feb 6;3(2):e1554. doi: 10.1371/journal.pone.0001554.
High-affinity naloxone binding to filamin a prevents mu opioid receptor-Gs coupling underlying opioid tolerance and dependence.
PMID: 18253501
ht tp://w ww.ncbi.nlm.nih.gov/pubmed/18253501
Proc Natl Acad Sci U S A. 2011 Dec 6;108(49):19778-83. doi: 10.1073/pnas.1115231108. Epub 2011 Nov 21.
Truncated G protein-coupled mu opioid receptor MOR-1 splice variants are targets for highly potent opioid analgesics lacking side effects.
PMID:
22106286 (been manually fixing it, but anybee know why pubmed likes to put the PMID and the actual PMID number on different lines when copypasta'ed even when they are in line on their home webpage? its irritating.
h ttp://
www.ncbi.nlm.nih.gov/pmc/articles/PMC2894766/Mol Pain. 2010; 6: 33.
Published online 2010 June 2. doi: 10.1186/1744-8069-6-33
PMCID: PMC2894766
A novel alternatively spliced isoform of the mu-opioid receptor: functional antagonism
h ttp://ww w.ncbi.nlm.nih.gov/pmc/articles/PMC3186080/
Pharmacol Rev. 2011 December; 63(4): 1001–1019.
doi: 10.1124/pr.111.004598
PMCID: PMC3186080
Functional Selectivity at the ?-Opioid Receptor: Implications for Understanding Opioid Analgesia and Tolerance
http://www.ncbi.nlm.nih.gov/pubmed/22106286?dopt=Abstract (the ones here before the Toad's requests here are all selected for separation in the thread because he thought they will bee of interest either to those working on novel opioids, specifically relevant to mono-acylated 6-position morphinans), or for those wishing to learn some real juicy, bleeding-edge opioid SAR

ht tp://w ww.ncbi.nlm.nih.gov/pubmed/20726836 (something on filamin-A high affinity binding by antagonists at nano/picomolar plasma concentrations and tolerance, got to bee quick here, little PC time left)
Br J Pharmacol. 2010 November; 161(5): 986–1001.
doi: 10.1111/j.1476-5381.2010.00824.x
PMCID: PMC2998681
Spinal or systemic TY005, a peptidic opioid agonist/neurokinin 1 antagonist, attenuates pain with reduced tolerance
ht tp://w ww.ncbi.nlm.nih.gov/pmc/articles/PMC2998681/
Pain Res Treat. 2012; 2012: 145965.
Published online 2012 March 21. doi: 10.1155/2012/145965
PMCID: PMC3324919
Effects of Combined Opioids on Pain and Mood in Mammals
h ttp://ww w.ncbi.nlm.nih.gov/pmc/articles/PMC3324919/
PLoS ONE. 2009; 4(1): e4282.
Published online 2009 January 27. doi: 10.1371/journal.pone.0004282
PMCID: PMC2628740
Naloxone's Pentapeptide Binding Site on Filamin A Blocks Mu Opioid Receptor–Gs Coupling and CREB Activation of Acute Morphine
h ttp://ww w.ncbi.nlm.nih.gov/pmc/articles/PMC2628740/
Toady would bee grateful if these references could perhaps bee supplied: (he puts them in this thread due to context and for accesibility to other bees looking at this and monoacyl morphinan esters, rather than generically in the reference req. thread)
J Pain. 2008 Aug;9(

:700-13. doi: 10.1016/j.jpain.2008.03.005. Epub 2008 May 12.
Oxycodone plus ultra-low-dose naltrexone attenuates neuropathic pain and associated mu-opioid receptor-Gs coupling
Neurochem Res. 1996 Nov;21(11):1347-51.
PMID: 8947924
Modulatory effects of Gs-coupled excitatory opioid receptor functions on opioid analgesia, tolerance, and dependence.
h ttp://ww w.ncbi.nlm.nih.gov/pubmed/8947924
Pain. 2000 Feb;84(2-3):121-31.
Antagonists of excitatory opioid receptor functions enhance morphine's analgesic potency and attenuate opioid tolerance/dependence liability.
PMID: 10666516
ht tp://w ww.ncbi.nlm.nih.gov/pubmed/10666516
Neuroscience. 2005;135(1):247-61.
Ultra-low-dose naloxone suppresses opioid tolerance, dependence and associated changes in mu opioid receptor-G protein coupling and Gbetagamma signaling.
PMID: 16084657
h ttp://w ww.ncbi.nlm.nih.gov/pubmed/16084657
Brain Res. 2008 Sep 22;1231:16-24. doi: 10.1016/j.brainres.2008.07.015. Epub 2008 Jul 12.
Low doses of cyclic AMP-phosphodiesterase inhibitors rapidly evoke opioid receptor-mediated thermal hyperalgesia in naïve mice which is converted to prominent analgesia by cotreatment with ultra-low-dose naltrexone.
ht tp://ww w.ncbi.nlm.nih.gov/pubmed/18656459
PMID: 18656459
Neurosignals. 2005;14(4):194-205.
Is paradoxical pain induced by sustained opioid exposure an underlying mechanism of opioid antinociceptive tolerance?
ht tp://w ww.ncbi.nlm.nih.gov/pmc/articles/PMC2628740/
PMID:16215302
Psychopharmacology (Berl). 2005 Jun;180(1):1-11. Epub 2005 Apr 14.
Effector antagonism by the regulators of G protein signalling (RGS) proteins causes desensitization of mu-opioid receptors in the CNS
PMID:
15830230
htt p://ww w.ncbi.nlm.nih.gov/pubmed/15830230
Neuropharmacology. 2003 Jul;45(1):82-95.
The GBeta5 subunit that associates with the R7 subfamily of RGS proteins regulates mu-opioid effects.
h ttp://ww w.ncbi.nlm.nih.gov/pubmed/12814661
Thats your lot for now guys, hope some of the provided full texts are of use/interest.
So if the requested papers could bee found for Toady, he would bee grateful.,