Cutaneous Sensory Mechanisms

Contains reports on two research projects.National Institutes of Health (Grant M-4235-(C1)

Cutaneous Sensory Mechanisms

Contains reports on two research projects.National Institutes of Health (Grant M-4235-(CZ)

The pain of low status: the relationship between subjective socio-economic status and analgesic prescriptions in a Scottish community sample

There is a strong positive relationship between objective measures of socioeconomic status (OSS) and general health. However, there is an increasing interest in the relationship between health and subjective socioeconomic status (SSS), which describes one’s perceived rank in relation to the rest of society, based on factors such as income, occupation, and education. While the relationship between SSS and general health is well2established, the relationship between SSS and pain has received little attention. Gathering both self2report questionnaire data and General Practitioner medical data from a large representative community sample in Scotland between 2012 and 2013 ( N = 1824), we investigated the relationship between SSS and prescriptions for analgesic drugs. We found that higher levels of SSS significantly predicted lower odds of participants having been prescribed at least one analgesic drug in the previous six months. We obtained this result even after controlling for OSS2related variables (education, occupational status, and geographical location) and demographic variables (age and gender). This suggests that, just like the relationship between SSS and general health, SSS has important effects on pain that go beyond the influence of OSS

Mas-related G-protein–coupled receptors inhibit pathological pain in mice

An important objective of pain research is to identify novel drug targets for the treatment of pathological persistent pain states, such as inflammatory and neuropathic pain. Mas-related G-protein–coupled receptors (Mrgprs) represent a large family of orphan receptors specifically expressed in small-diameter nociceptive primary sensory neurons. To determine the roles of Mrgprs in persistent pathological pain states, we exploited a mouse line in which a chromosomal locus spanning 12 Mrgpr genes was deleted (KO). Initial studies indicated that these KO mice show prolonged mechanical- and thermal-pain hypersensitivity after hind-paw inflammation compared with wild-type littermates. Here, we show that this mutation also enhances the windup response of dorsal-horn wide dynamic-range neurons, an electrophysiological model for the triggering of central pain sensitization. Deletion of the Mrgpr cluster also blocked the analgesic effect of intrathecally applied bovine adrenal medulla peptide 8–22 (BAM 8–22), an MrgprC11 agonist, on both inflammatory heat hyperalgesia and neuropathic mechanical allodynia. Spinal application of bovine adrenal medulla peptide 8–22 also significantly attenuated windup in wild-type mice, an effect eliminated in KO mice. These data suggest that members of the Mrgpr family, in particular MrgprC11, may constitute an endogenous inhibitory mechanism for regulating persistent pain in mice. Agonists for these receptors may, therefore, represent a class of antihyperalgesics for treating persistent pain with minimal side effects because of the highly specific expression of their targets