title: Age related changes of enkephalin in rat spinal cord.
abstract: Met-enkephalin immunoreactive material content was found to be decreased in the cervical and thoracic segments of the spinal cord from rats aged 25 months as compared to young, 3-month-old, rats. No age-related variations were detectable at the lumbar level. Bio-Gel P 30 column chromatography of thoracic segment extracts indicates that the composition of the immunoreactive material is similar in the two age-groups investigated. At the thoracic level opiate receptor binding was also measured. Opiate receptor number is increased in the thoracic segments of the spinal cord from older rats. These age-related changes in immunoreactive Met-enkephalin content and opiate receptor number at spinal levels may contribute to determine an altered pain sensitivity during aging.
mesh_terms: D000375:Aging; D000818:Animals; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives / Q000032:analysis* / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000378:metabolism; D013116:Spinal Cord / Q000254:growth & development*
chemical_list: D011957:Receptors, Opioid; D004744:Enkephalin, Methionine; C028208:metkephamid