Can the Human Body Make Its Own Morphine?

By Andrew Moseman | April 28, 2010 2:32 pm

MorphineWho needs poppy plants to produce morphine? Last month scientists said they’d isolated the genes those plants use to synthesize the narcotic chemical and made it themselves in a lab. Now, in a study in the Proceedings of the National Academy of Sciences,  another team has suggested that we mammals might possess the pathway to create our own morphine.

Because we have receptors for the opiate in our brains (which makes it such an effective and addictive painkiller), and because morphine traces show up in our urine, scientists had long wondered if animals could produce the drug themselves. But studies using living animals yielded inconclusive results because of possible contamination from external sources of morphine in their food or in the environment [Nature]. In addition, the body breaks down and changes morphine, which complicates the task.

To sort out this mess, researchers injected mice with tetrahydropapaveroline (THP). Human brain cells have this chemical, and plants use it to make morphine. After the injection, mice started to turn the THP into salutaridine. In morphine-producing poppy plants salutaridine is then converted to thebaine, which undergoes further reactions to become morphine. The researchers show that mice can also do that chemical conversion, as well as others needed to generate morphine [Science News].

“This paper seems to be one of the most definitive I’ve seen,” says Chris Evans, a neurobiologist and expert on opioid drugs at the University of California, Los Angeles. “They’ve convincingly shown that there’s a pathway there which could possibly produce morphine” [Nature News]. But to what end? This study simply showed that the morphine-producing pathway is possible; it didn’t find traces in tissue. Thus, it can’t say for sure that mammals do produce morphine naturally, nor for what it would be used. Pain relief seems the obvious answer, since that’s the most common use of plant-created morphine, but the scientists don’t know if the body could make enough for that purpose.

The other outstanding question is: Did animals and plants evolve these pathways separately, or do parts of it date all the way back to simple common ancestors before the kingdom split? Coauthor Meinhart Zenk is leaning toward independent evolution, because the early parts of the process are different.

Related Content:
80beats: The Poppy’s Secret: Scientists Find the Genes That Make Morphine
80beats: To Help Heroin Addicts, Give Them… Prescription Heroin?
80beats: A Prompt Dose of Morphine Could Cut PTSD Risk for Wounded Soldiers
DISCOVER: The Biology of Addiction
DISCOVER: Vital Signs, all our medical mysteries

Image: flickr / Evil Erin

CATEGORIZED UNDER: Health & Medicine, Mind & Brain
  • jumblepudding

    I think it was found that cow’s milk, at least, contains compounds similar to morphine, which possibly developed pacify and calm the calf as well as create a subtle “chemical” connection to the mother.

  • http://sinville-sinville.blogspot.com/ Mary Stack

    Totally fascinating topic. I always thought there must be a grain of truth to the idea of self-pain control. The best example, is the nature videos of animals attacking and eating another alive. The doomed animal will disengage from the survival fight and accept the death. I know our bodies and most importantly, our brains have some equivalent mechanism. Women who have experienced a natural birth may be more likely to comprehend this process. I have always wondered, if my ability and preference to tough out pain was inherited from my native Indian ancestry.

  • nothingmuchly

    Aren’t endorphins the same as morphine? The word is an acronym for endogenous morphine, after all..

  • scott

    Dear Brain, please make more morphine,
    thanks, me.

  • http://blogs.discovermagazine.com/80beats/2010/04/28/can-the-human-body-make-its-own-morphine/ Naheed

    Yes it seems body does make morphine, this is specially true in some people.As with the enhancemnet of stress some are found to sleep more, may be this is body’s way of coping with stress with the production of morphine like substances..endorphine and enkephaline..acting on brain receptors. It is there in Quran..where Allah says…I have given you diseases and their cures too within you…like antibodies, interferons, prostaglandins..to name a few, while many more have to be explored.To cure oneself one has to have a strong brain too.i.e. will power…

  • Brian Too

    Yeah, I thought that the receptors for endorphins were basically the same as the receptors for morphine and equivalent drugs. Which is why morphine is chemically active in our bodies–it’s an external source for a drug already produced internally.

    Nor is the match between morphine and tissue receptors accidental. This isn’t a case of a drug mimic, just as certain compounds mimic estrogen. The morphine key fits the receptor lock because the lock was meant to fit that key.

  • The Rev

    Would naturally produced morphine show up in urine and at levels high enough to be detected on a drug test at 150 ng/ml?

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