1. ¹Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka, Japan
2. ²Department of Integrative Physiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan

Correspondence: Dr H Sei, Department of Integrative Physiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan. Tel/Fax: +81 88 633 9251; E-mail: sei@basic.med.tokushima-u.ac.jp

³These two authors contributed equally to this work.

⁴Present address: Advanced Research Institute for Bioscience, Waseda University, Tokyo 169-0072, Japan.

Received 10 December 2004; Revised 22 February 2005; Published online 13 April 2005.

Abstract

Rapid eye movement (REM)-sleep related changes in arterial pressure (AP) and heart rate (HR) were observed in homozygous and heterozygous adenosine A_2A receptor (A2AR) knockout (KO) mice, and the corresponding wild-type mice. During REM sleep, the mean AP (MAP) and HR were clearly increased in the homozygous A2AR KO mice, while, in the wild-type mice, they were decreased or maintained at the same level. Neither homozygous nor heterozygous A2AR KO mice showed significant difference in diurnal pattern and the hourly values of MAP and HR compared to the wild-type mice. From these findings, it is likely that the adenosine A2AR is involved in autonomic regulation during REM sleep.