Manipulation of the Lighting Schedule Can Modify the Pharmacological Effects of Theophylline In Chick Embryos

Yuji Yoshiyama, Takashi Sugiyama, Nobuo Kubota, Hiroyuki Miyazaki, Kazuru Saito, Fumiya Tomonaga, Hideyo Shimada, Shigehiro Ohdo

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The effect of the lighting schedule on the pharmacological action of theophylline was studied in chick embryos. Fertile eggs of White Leghorns were incubated and investigated, on two occasions, under constant light conditions or under constant dark conditions. A sigle injection of theophylline 2.14,4.29,8.57 and 17.14 mg/egg into the air sac of fertile eggs was carried out on the 16th day of incubation. Electrocardiograms (ECGs) were recorded 0 to 60 min after drug injection. After drug injection, heart rate increased under constant light conditions, but decreased under dark conditions. In addition, arrhythmia was produced by theophylline, 17.14mg/egg, under constant dark conditions. These results indicate that the manipulation of the lighting schedule may have a marked influence on the pharmacological effects of theophylline in chick embryos.

Original languageEnglish
Pages (from-to)776-778
Number of pages3
JournalBiological and Pharmaceutical Bulletin
Issue number5
Publication statusPublished - Jan 1 1995


All Science Journal Classification (ASJC) codes

  • Pharmacology
  • Pharmaceutical Science

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