Opioid receptors outside the brain targeted in rats; new direction for painkillers
"People living with chronic pain have few innovative analgesic options available to them outside of systemic opioids. Prolonged use of these opioids can result in respiratory depression, tolerance, addiction, and overdose," says senior study author Nathaniel Jeske of the University of Texas Health Science Center at San Antonio. "Being able to increase the responsiveness of peripheral opioid receptor systems could lead to a reduction in systemic opioid administration , thereby reducing the incidence of side effects." Most clinical opioids currently available target mu opioid receptors, including those located in the brain, and therefore have a high potential for abuse. By contrast, drugs targeting delta opioid receptors in the peripheral nervous system rather than the brain and spinal cord produce fewer side effects in animals and have a much lower abuse potential. However, delta opioid receptors in peripheral tissues only become activated in the presence of inf...