In a previous report (Hamase, K. et al., Biochim Biophys Acta 1134: 214-222
(1997)), we showed that the rat pineal gland contains D-leucine (D-Leu) as
well as D-aspartic acid (D-Asp). In this communication we report alteratio
ns in the content of these D-amino acids during anesthesia. The D-Asp conte
nt was significantly increased from 2.8 to 5.0, 4.8 and 5.8 nmol/pineal gla
nd by administration of ether, urethane and pentobarbital, respectively. In
contrast, the D-Leu content was decreased by administration of urethane or
pentobarbital. The D-Leu content decreased from 4.2 to 2.2 pmol/pineal gla
nd 4 hours after administration of urethane, although the content remained
unchanged until 1.5 hours after administration. The content of the L-enanti
omers of these amino acids were not affected by anesthesia. The urethane-in
duced decrease in D-leucine content was almost completely suppressed by a b
eta-agonist, (-)-isoproterenol, whereas the agonist itself had no effect.