Different inhibitory effects of sevoflurane on hyperreactive airway smooth muscle contractility in ovalbumin-sensitized and chronic cigarette-smoking guinea pig models.
BACKGROUND
The authors hypothesized that sevoflurane had different inhibitory effects on hyperreactive airway smooth muscle contractility in different types of hyperreactive airway models.


METHODS
The effects of sevoflurane on hyperreactive airways in ovalbumin-sensitized and chronic cigarette-smoking guinea pig models were investigated by measuring (1) total lung resistance, (2) smooth muscle tension and intracellular concentration of free Ca, (3) voltage-dependent Ca channel activity, and (4) cyclic adenosine monophosphate levels.


RESULTS
Ovalbumin and muscarinic airway hyperreactivity was seen in ovalbumin-sensitized animals. Enlarged alveolar ducts/alveoli and lesser muscarinic hyperreactivity were observed in chronic cigarette-smoke animals. Although sevoflurane inhibited the acetylcholine-induced increase in total lung resistance in the control and ovalbumin-sensitized models, the anesthetic had a smaller effect in the chronic cigarette-smoking model. Similarly, in the chronic cigarette-smoking model, sevoflurane had a smaller inhibitory effect on carbachol-induced muscle contraction and increase in intracellular concentration of free Ca. Sevoflurane also had a smaller inhibitory effect on voltage-dependent Ca channel activity in the chronic cigarette-smoking group than in the other two groups. The sevoflurane-induced increase in cyclic adenosine monophosphate that was seen in the control and ovalbumin-sensitized groups was significantly suppressed in the chronic cigarette-smoking group.


CONCLUSIONS
Although sevoflurane potently inhibited airway contractility in control and ovalbumin-sensitized models, the anesthetic had a smaller effect in a chronic cigarette-smoking model. The different inhibitory effects of sevoflurane on airway contractility depend, at least in part, on different effects on voltage-dependent Ca channel activity and cyclic adenosine monophosphate level.
Iwasaki
Soshi
S
Department of Anesthesiology, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo, Hokkaido 060-8543, USA.
Yamakage
Michiaki
M
Satoh
Jun-Ichi
J
Namiki
Akiyoshi
A
D000403:Airway Resistance / Q000187:drug effects; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D016535:Bronchial Hyperreactivity / Q000139:chemically induced* / Q000503:physiopathology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D000242:Cyclic AMP / Q000378:metabolism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008170:Lung Compliance / Q000502:physiology; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000166:cytology / Q000502:physiology*; D010047:Ovalbumin / Q000276:immunology*; D012130:Respiratory Hypersensitivity / Q000503:physiopathology*; D000077149:Sevoflurane; D012907:Smoking / Q000503:physiopathology*; D014132:Trachea / Q000502:physiology
D018685:Anesthetics, Inhalation; D015220:Calcium Channels; D008738:Methyl Ethers; D000077149:Sevoflurane; D010047:Ovalbumin; D000242:Cyclic AMP