Cisplatin-induced long-term dynorphin A-immunoreactivity in cell somata of rat area postrema neurons

Goichi Tsukamoto, Hiroyuki Ichikawa, Motoi Kobashi, Yosuke Yamada, Takeshi Kikuchi, Hiroshi Mese, Akira Sasaki

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4 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)122-126
Number of pages5
JournalNeuroscience Letters
Issue number2
Publication statusPublished - Sep 7 2007


  • Anorexia
  • Cisplatin
  • Delayed emesis
  • Dynorphin
  • Immunohistochemistry
  • Pica

ASJC Scopus subject areas

  • Neuroscience(all)


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