Differential changes in tachykinins after kainic acid-induced seizures in the rat.
Changes in concentrations of the tachykinins substance P, neurokinin A and neurokinin B were investigated in rat brains after kainic acid-induced seizures. Two different antisera, one detecting substance P specifically and one recognizing neurokinins A and B but not substance P, were used. Subsequently to the acute seizures (3 h after kainic acid) significant decreases (by 25-40%) in total neurokinin (A + B) and substance P immunoreactivities were observed in the frontal cortex, dorsal hippocampus and striatum. Depending on the brain area neurokinin immunoreactivity recovered 1-3 days after injection of the toxin and was significantly increased in the frontal cortex (by 40-60%) and the hippocampus (by 100-300%) after 10-60 days. Further analysis by high pressure liquid chromatography revealed that increases in both neurokinin A and neurokinin B concentrations contributed to the increases in total neurokinin immunoreactivity 30 days after kainic acid. At the same time significantly increased levels were also observed for substance P in the frontal cortex (by 30%). Furthermore, increases were also observed in the concentrations of neuropeptide K and gamma-preprotachykinin-A(72-92) in the frontal cortex and the hippocampus 30 days after the kainic acid treatment.
Department of Pharmacology, University of Innsbruck, Austria.
G
G
Sperk
J
J
Marksteiner
A
A
Saria
C
C
Humpel
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D007608:Kainic Acid; D008297:Male; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism*; D015320:Tachykinins / Q000378:metabolism*
D015320:Tachykinins; D013373:Substance P; D007608:Kainic Acid