[Effects of pentobarbital sodium on rhythmical respiration of neonatal rat medullary preparations].
OBJECTIVE
To study the effects of pentobarbital sodium in generation and modulation of rhythmical respiration in neonatal rats.


METHODS
The effects of pentobarbital sodium were examined on hypoglossal nerve (XII) rootlets and inspiratory neurons in the medullary preparations including the medial region of the nucleus retrofacialis, pre-Bötzinger complex and the dorsal respiratory group of neonatal rats aged 0-3 days. The electrical activity of XII nerve rootlets and inspiratory neurons were recorded. Different doses of pentobarbital sodium (20, 40, 60, 80 micromol/L) were added into modified Krebs solution to observe changes in the discharge activity of XII nerve and inspiratory neurons. Bicuculline was used to further investigate the mechanisms that pentobarbital sodium suppresses respiration.


RESULTS
The discharge activity inhibition of XII nerve was increased as pentobarbital sodium doses increased from 20 to 60 micromol/L, but no significant difference was observed between the doses of 60 and 80 micromol/L. Bicuculline can partly restore the rhythmical respiration discharge activity.


CONCLUSIONS
Pentobarbital sodium can suppress respiration partly via GABAA receptors.
Chen
Juan
J
Department of Physiology, Southern Medical University, Guangzhou 510515, China. chenjuan_1980@hotmail.com
Zou
Zhi-peng
ZP
Wu
Zhong-hai
ZH
D000759:Adjuvants, Anesthesia / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D004305:Dose-Response Relationship, Drug; D008526:Medulla Oblongata / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D010424:Pentobarbital / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000502:physiology; D012119:Respiration / Q000187:drug effects; D012125:Respiratory Center / Q000187:drug effects* / Q000502:physiology
D000759:Adjuvants, Anesthesia; D011963:Receptors, GABA-A; D010424:Pentobarbital