[Thio- and oxybarbiturates inhibit peristalsis in the Guinea-pig ileum in vitro].
BACKGROUND
Inhibition of gastrointestinal motility by drugs used for anaesthesia or sedation in critically ill patients in the ICU is a major problem leading to various complications. Thus this study examines whether the thio- and oxybarbiturates thiopentone and pentobarbitone exert an inhibitory effect on intestinal peristalsis.


METHODS
Peristalsis in isolated segments of the guinea-pig small intestine was elicited by distension of the gut wall through a rise of intraluminal pressure and recorded via the intraluminal pressure changes associated with the aborally moving peristaltic contractions. Thiopentone and pentobarbitone (0.1 - 300 microM)-induced inhibition of peristalsis was reflected by an increase of the peristaltic pressure threshold (PPT).


RESULTS
Thiopentone (EC50 = 19,8 microM) and pentobarbitone (EC50 = 99.7 micro M) concentration-dependently increased the PPT. While the vehicle (saline) and 0.1 - 10 micro M thiopentone and pentobarbitone were without any effect on the PPT, 100 micro M caused a significant increase in PPT, and complete abolition of peristalsis occurred after 300 micro M thiopentone or pentobarbitone in all segments tested. Inhibition was reversed by changing the bath solution.


CONCLUSIONS
Thio- and oxybarbiturates inhibit intestinal peristalsis in the guinea-pig ileum. It is assumed that thiopentone and pentobarbitone affect propulsive peristalsis also in the human small intestine.
Herbert
M K
MK
Klinik für Anaesthesiologie der Universität Würzburg. mherbert@anaesthesie.uni-wuerzburg.de
Berg
W
W
Kublik
A
A
Holzer
P
P
Roewer
N
N
D000818:Animals; D001463:Barbiturates / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004576:Electromyography; D006168:Guinea Pigs; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009130:Muscle, Smooth / Q000187:drug effects*; D010424:Pentobarbital / Q000494:pharmacology; D010528:Peristalsis / Q000187:drug effects*; D011312:Pressure; D013858:Thiobarbiturates / Q000494:pharmacology*; D013874:Thiopental / Q000494:pharmacology
D001463:Barbiturates; D006993:Hypnotics and Sedatives; D013858:Thiobarbiturates; D010424:Pentobarbital; D013874:Thiopental