Kainic acid modifies mu-receptor binding in young, adult, and elderly rat brain.
Mu-receptor binding changes were evaluated following the kainic acid (KA)-induced status epilepticus (SE) in young, adult, and elderly animals. Male Wistar rats were used as follows: young rats (15 days old) were treated with KA (7 mg/kg) and sacrificed 72 h (YKA3d) or 35 days (YKA35d) after SE; adult (90 days old) (AKA1d and AKA40d) and elderly rats (1-year-old) (EKA1d and EKA40d) were injected with KA (10 mg/kg) and then sacrificed 24 h or 40 days following SE. Their brains were processed for an autoradiography assay for mu-receptors. The YKA3d group showed increased values in dentate gyrus (39%) and a decrease in substantia nigra (26%); YKA35d animals had a reduction in caudate putamen (29%) and in substantia nigra (20%). The AKA1d group exhibited increased mu-receptors in caudate putamen (49%), cingulate (415%), frontal (52%), and temporal (53%) cortices: substantia nigra (56%), dentate gyrus (48%). and CA2 field of hippocampus (53%). The AKA40d group showed increased values in sensorimotor cortex (45%), anterior (39%), medial (65%), basolateral (202%), and central (32%) amygdaloid nuclei; dentate gyrus (80%) as well as CA2 (80%) and CA3 (49%) fields of hippocampus. The EKA1d group presented decreased mu-receptor binding in piriform (16%) and enthorinal (22%) cortices as well as in anterior amygdala nucleus (17%). The EKA40d group showed reduced values in sensorimotor cortex (14%) and substantia nigra (27%). The present results indicate that the mu-binding changes following SE depend on the rate of brain maturation.
Pérez-Cruz
Claudia
C
División de Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente: Av. México-Xochimilco 101, Mexico. D.F. C.P., 14370 Mexico.
Rocha
Luisa
L
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D003292:Convulsants / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000493:pharmacokinetics; D004827:Epilepsy / Q000378:metabolism* / Q000503:physiopathology; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018847:Opioid Peptides / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D017450:Receptors, Opioid, mu / Q000187:drug effects / Q000378:metabolism*; D013226:Status Epilepticus / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D003292:Convulsants; D018847:Opioid Peptides; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D007608:Kainic Acid