[Effect of ketamine combined with penehyclidine hydrochloride on the expression of synaptophysin in the brain of neonatal rats].
OBJECTIVE
To study the effects of ketamine combined with penehyclidine hydrochloride on the learning and memory abilities and the expression of synaptophysin in the hippocampus CA3 region in the brain of neonatal rats.


METHODS
Eighty seven-day-old Sprague-Dawly rats were randomly intraperitoneally injected with 50 mg/kg of ketamine (K group), 2 mg/kg of penehyclidine hydrochloride (P group), 50 mg/kg of ketamine plus 2 mg/kg penehyclidine hydrochloride (PK group) or normal saline (control group). The rats were trained and tested in a Morris water maze 14 days after administration. The immunhistochemical method was used to ascertain the expression of synaptophysin in the hippocampus CA3 region 24 hrs, 14 days and 28 days after administration.


RESULTS
In the Morris water maze training, the rats in the PK group performed worst, followed by the K group. The rats from the P and NS groups performed well. Compared with the NS group, the expression of synaptophysin in the K and the PK groups decreased significantly 24 hrs and 14 days after administration (p<0.05). The PK group had lower synaptophysin expression than the K group 24 hrs and 14 days after administration (p<0.05). Up to 28 days after administration, the synaptophysin expression increased in all of the four groups and there were no significant differences between groups.


CONCLUSIONS
Ketamine combined with penehyclidine hydrochloride may inhibit more significantly learning and memory abilities and the synaptophysin expression in the hippocampus CA3 region than ketamine alone in neonatal rats. Penehyclidine hydrochloride alone has no effect on learning and memory abilities and the synaptophysin expression. The synaptophysin expression may increase to a normal level by training and with increasing age.
Lin
Lei
L
Department of Anesthesiology, Affiliated Union Hospital of Fujian Medical University, Fuzhou 350001, China.
Zhang
Liang-Cheng
LC
Guo
Yong-Zheng
YZ
D000818:Animals; D000831:Animals, Newborn; D018680:Cholinergic Antagonists / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D006624:Hippocampus / Q000737:chemistry / Q000187:drug effects*; D007649:Ketamine / Q000494:pharmacology*; D018782:Maze Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects; D011812:Quinuclidines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D016708:Synaptophysin / Q000032:analysis*
D018680:Cholinergic Antagonists; D018691:Excitatory Amino Acid Antagonists; D011812:Quinuclidines; D016194:Receptors, N-Methyl-D-Aspartate; D016708:Synaptophysin; C486140:penehyclidine; D007649:Ketamine