Riluzole disrupts autoresuscitation from hypothermic respiratory arrest in neonatal hamsters but not rats.
We examined the effect of riluzole on expression of the central respiratory rhythm and the ability of neonates to autoresuscitate from hypothermic respiratory arrest using in vitro brainstem-spinal cord preparations of rats and hamsters. At a constant temperature of 27 degrees C, riluzole (5-200 microM) decreased the burst amplitude of respiratory-related motor discharge, but had little effect on the fictive respiratory frequency in rat preparations. In contrast, in hamster preparations, riluzole reduced fictive respiratory frequency, but had little effect on burst amplitude. Hamster preparations were more cold-tolerant than rat preparations, with respiratory arrest and autoresuscitation occurring at lower temperatures during cooling of the preparation. This difference was removed by incubation with riluzole (5 microM); riluzole significantly increased the temperature at which fictive respiration arrested and restarted in hamster preparations, but had no effect in rat preparations. The species differences observed in this study may reflect fundamental differences in the relative role of riluzole-sensitive mechanisms in the expression of the respiratory rhythm in early development of an altricial vs. a more precocial species.
Fong
Angelina Y
AY
Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC, Canada V6T 1Z4. fong@zoology.ubc.ca
Marshall
Lieneke H
LH
Milsom
William K
WK
D000200:Action Potentials / Q000187:drug effects; D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001933:Brain Stem / Q000187:drug effects; D006224:Cricetinae; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D007035:Hypothermia / Q000503:physiopathology*; D066298:In Vitro Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000187:drug effects*; D012125:Respiratory Center / Q000187:drug effects; D015656:Respiratory Mechanics / Q000187:drug effects*; D012151:Resuscitation; D019782:Riluzole / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects; D013696:Temperature
D018691:Excitatory Amino Acid Antagonists; D019782:Riluzole