Capsaicin does not change tissue levels of glutamic acid, its uptake, or release in the rat spinal cord.
Capsaicin treatment (50 mg/kg, subcutaneous) of newborn rats resulted in 1 75% decrease of substance P immunoreactivity in the dorsal spinal cord of the adult animal, but failed to affect levels of the proposed sensory neurotransmitter glutamic acid or to alter high-affinity uptake of [3H]glutamic acid into synaptosomes of the same tissue. Furthermore, capsaicin (30 microM) in vitro had no influence on the release of [3H]glutamic acid from spinal cord P2 fractions of untreated adult rats, but induced a marked release of substance P. The results suggest that, in contrast to substance P fibers, neurons containing glutamic acid are not sensitive to capsaicin. Eleven other neurochemical parameters measured in the spinal cord did not appear to be changed by the treatment with capsaicin, suggesting a considerable neurochemical selectivity of the lesion.
D000818:Animals; D002211:Capsaicin / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism
D005231:Fatty Acids, Unsaturated; D005971:Glutamates; D013373:Substance P; D018698:Glutamic Acid; D002211:Capsaicin