Featured Research

from universities, journals, and other organizations

Dissimilar interaction of opioid receptors may explain why men and women experience pain differently

Date:
August 19, 2011
Source:
SUNY Downstate Medical Center
Summary:
Women and men experience pain, particularly chronic pain, very differently. The ability of some opioids to relieve pain also differs between women and men. Now, research has revealed that the same major types of opioid receptor interact differently, depending on sex.

Women and men experience pain, particularly chronic pain, very differently. The ability of some opioids to relieve pain also differs between women and men. While it has been recognized since the mid-nineties that some narcotic analgesics are more effective in women than men, the reason for this difference was largely unknown.

Related Articles


Narcotic analgesics decrease pain by activating opioid receptors, which are located on nerves that transmit painful sensations. Since levels of mu, delta, and kappa opiate receptors -- the three main types of opioid receptor in the brain and spinal cord -- are not thought to differ dramatically in men and women, it was difficult to understand why the effectiveness of some painkillers is dependent on sex.

Now, research supported by the National Institute of Drug Abuse (NIDA) has revealed that the same major types of opioid receptor interact differently, depending on sex. The spinal cord of female laboratory animals was found to contain almost five times more kappa-mu heterodimer -- a complex of mu-opioid and kappa-opioid receptor -- than the spinal cord of male animals. Furthermore, the amount of mu-kappa heterodimer in the spinal cord of the females was about four times higher when their levels of estrogen and progesterone were at their peak. Subsequently, researchers found that both estrogen and progesterone are critical for the formation of mu-kappa opioid receptor heterodimers.

This research was conducted by Alan Gintzler, PhD, professor of biochemistry, Department of Obstetrics and Gynecology, and his senior collaborators Sumita Chakrabarti, PhD, and Nai-Jiang Liu, PhD, at the State University of New York (SUNY) Downstate Medical Center

The discovery of a mu-kappa opioid receptor complex that is more prevalent in the spinal cord of females than males and that is synchronized with the ebb and flow of ovarian hormones could explain why drugs used to treat pain, such as pentazocine, nalbuphine, and butorphanol -- which primarily act on mu-opioid and kappa-opioid receptors -- are more effective in women than men. The activation of the kappa-opioid receptor within the kappa-mu-opioid receptor complex could provide a mechanism for recruiting the pain-relieving functions of spinal kappa-opioid receptors without also activating their pain-promoting functions.

The research by Drs. Gintzler, Liu, and Chakrabarti, which was recently published in the Proceedings of the National Academy of Sciences and the Journal of Neuroscience, suggests that kappa-mu opioid receptor heterodimers could function as a molecular switch that shifts the action of kappa-opioid receptors and endogenous chemicals that act on them from pain-promoting to pain-alleviating. Kappa-mu opioid receptor heterodimers could serve as a novel molecular target for pain management in women.

Dr. Gintzler's research suggests that physicians should take the stage of the menstrual cycle into account before deciding which drugs to prescribe to treat pain in women. While some drugs might be very effective in treating pain at times when estrogen and progesterone levels are high, they could heighten pain when levels are low. "This consideration could become even more critical in managing pain in postmenopausal and elderly women," said Dr. Gintzler. "Further research is needed to flesh out these possibilities."

The Journal of Neuroscience paper appeared in the August 17, 2011 edition.


Story Source:

The above story is based on materials provided by SUNY Downstate Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. N.-J. Liu, S. Chakrabarti, S. Schnell, M. Wessendorf, A. R. Gintzler. Spinal Synthesis of Estrogen and Concomitant Signaling by Membrane Estrogen Receptors Regulate Spinal κ- and μ- Opioid Receptor Heterodimerization and Female-Specific Spinal Morphine Antinociception. Journal of Neuroscience, 2011; 31 (33): 11836 DOI: 10.1523/JNEUROSCI.1901-11.2011

Cite This Page:

SUNY Downstate Medical Center. "Dissimilar interaction of opioid receptors may explain why men and women experience pain differently." ScienceDaily. ScienceDaily, 19 August 2011. <www.sciencedaily.com/releases/2011/08/110818132223.htm>.
SUNY Downstate Medical Center. (2011, August 19). Dissimilar interaction of opioid receptors may explain why men and women experience pain differently. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2011/08/110818132223.htm
SUNY Downstate Medical Center. "Dissimilar interaction of opioid receptors may explain why men and women experience pain differently." ScienceDaily. www.sciencedaily.com/releases/2011/08/110818132223.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Yoga Could Be As Beneficial For The Heart As Walking, Biking

Yoga Could Be As Beneficial For The Heart As Walking, Biking

Newsy (Dec. 17, 2014) Yoga can help your weight, blood pressure, cholesterol and heart just as much as biking and walking does, a new study suggests. Video provided by Newsy
Powered by NewsLook.com
1st Responders Trained for Autism Sensitivity

1st Responders Trained for Autism Sensitivity

AP (Dec. 16, 2014) More departments are ordering their first responders to sit in on training sessions that focus on how to more effectively interact with those with autism spectrum disorder (Dec. 16) Video provided by AP
Powered by NewsLook.com
Guys Are Idiots, According To Sarcastic Study

Guys Are Idiots, According To Sarcastic Study

Newsy (Dec. 12, 2014) A study out of Britain suggest men are more idiotic than women based on the rate of accidental deaths and other factors. Video provided by Newsy
Powered by NewsLook.com
Believing in Father Christmas Good for Children's Imaginations

Believing in Father Christmas Good for Children's Imaginations

AFP (Dec. 12, 2014) As the countdown to Christmas gets underway, so too does the Father Christmas conspiracy. But psychologists say that telling our children about Santa, flying reindeer and elves is good for their imaginations. Duration: 01:57 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins