title: Radioimmunoassay of enkephalin: distribution in the cat spinal cord and the effect of superficial peroneal nerve stimulation.
abstract: A sensitive radioimmunoassay (RIA) for methionine-enkephalin (met-enk) was developed and used to measure enkephalins in different sagital sections of the L7-S1 spinal segment of the acute decerebrated spinal cat. Dorsal spinal sections were found to contain about three times higher concentrations of enkephalins than the ventral sections. Enkephalins in each section were also compared between cats which received supramaximal electrical stimulation of the superficial peroneal nerve (SP nerve) and those which received no stimulation. The SP nerve stimulation did not alter the enkephalin concentrations in all the sections examined. The results of this study support a hypothesis that enkephalinergic neurons are present in the dorsal horn of the cat spinal cord and provide evidence that enkephalin concentration in the spinal cord is not affected by SP nerve stimulation sufficient to evoke a C-fiber reflex in the acute decerebrated spinal cat.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002415:Cats; D003655:Decerebrate State; D004558:Electric Stimulation; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000032:analysis / Q000378:metabolism*; D005260:Female; D008297:Male; D010543:Peroneal Nerve / Q000502:physiology*; D011817:Rabbits / Q000276:immunology; D011863:Radioimmunoassay; D013116:Spinal Cord / Q000378:metabolism*
chemical_list: D004723:Endorphins; D004745:Enkephalins