Cisplatin-induced long-term dynorphin A-immunoreactivity in cell somata of rat area postrema neurons
- 作者：Goichi Tsukamoto ; Hiroyuki Ichikawa ; Motoi Kobashi ; Yosuke Yamada ; Takeshi Kikuchi ; Hiroshi Mese ; Akira Sasaki
- 关键词：Dynorphin ; Cisplatin ; Anorexia ; Delayed emesis ; Pica ; Immunohistochemistry
- 刊名：Neuroscience Letters
- 出版年：2007
- 期刊代码：52_03043940
- 类别：neu
- 出版时间：7 September 2007
- 卷：424
- 期：2
- 页码：122-126
- 文件大小：567 K
摘要
We evaluated long-term dynorphin A-immunoreactivity in the rat area postrema (AP) after the administration of cisplatin. First, rats were given 1, 5 and 10 mg/kg body weight cisplatin (i.p.) and their behavior was monitored for 72 h. We observed a delayed increase in pica 24-72 h after injection, compared to the 24 h before injection. We attributed this to the cisplatin injection. Pica was defined as an increase in the intake of non-nutritional matter such as kaolin. Administration of 1, 5 and 10 mg/kg cisplatin led to an increase in kaolin intake on day 1. Administration of 5 and 10 mg/kg of cisplatin led to decreased intake of laboratory chow (MF) on days 1–3, but 10 mg/kg cisplatin causes an excessive aggravation of their condition. Following this behavioral experiment, we immunohistochemically examined the induction of dynorphin A in the AP at 24, 48 and 72 h post-administration of 1 and 5 mg/kg cisplatin. Administration of 5 mg/kg cisplatin caused dynorphin A to accumulate gradually in the neurosoma of the AP neurons, and the numbers of positive AP neurosomata at 48 and 72 h post-administration were higher than following an equal dosage of 0.9%NaCl. These findings suggest that dynorphin A increases in the central nervous system for a long time following administration, and causes certain behavioral and clinical changes, including those related to appetite and nausea.