Effect of capsaicin pretreatment on substance P binding to synaptic vesicles.
Newborn or adult rats were pretreated with 50 mg kg-1 capsaicin. At the age of 2 to 4 months, binding of 125I-labelled Tyr8-substance P to synaptic vesicles prepared from different regions of the nervous system was examined. In both groups, capsaicin pretreatment led to a significant decrease in the number of binding sites in dorsal roots and spinal cord without having an effect on affinity. This decrease parallels the depletion of the substance P content (Gamse et al., 1980) and can be explained by degeneration of primary sensory neurons in newborn treated rats and by depletion of vesicles in adult treated rats.
D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D001665:Binding Sites / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D008297:Male; D051381:Rats; D013116:Spinal Cord / Q000378:metabolism; D013126:Spinal Nerve Roots / Q000378:metabolism; D013373:Substance P / Q000378:metabolism*; D013572:Synaptic Vesicles / Q000378:metabolism*
D005231:Fatty Acids, Unsaturated; D013373:Substance P; D002211:Capsaicin