Effects of in vivo lidocaine administration at the time of ischemia and reperfusion on in vitro contractility of equine jejunal smooth muscle.
OBJECTIVE
To determine whether administration of lidocaine during ischemia and reperfusion in horses results in concentrations in smooth muscle sufficient to protect against the negative consequences of ischemia-reperfusion injury on smooth muscle motility.


METHODS
12 horses.


METHODS
Artificial ischemia and reperfusion injury of jejunal segments was induced in vivo in conjunction with lidocaine treatment during ischemia (IRL) or without lidocaine treatment (IR). Isometric force performance was measured in vitro in IRL and IR smooth muscle preparations with and without additional in vitro application of lidocaine. Lidocaine concentrations in smooth muscle were determined by means of high-performance liquid chromatography. To assess the influence of lidocaine on membrane permeability, activity of creatine kinase and lactate dehydrogenase released by in vitro incubated tissues was determined biochemically.


RESULTS
In vivo administration of lidocaine allowed maintenance of contractile performance after an ischemia and reperfusion injury. Basic contractility and frequency of contractions were significantly increased in IRL smooth muscle tissues in vitro. Additionally, in vitro application of lidocaine achieved further improvement of contractility of IR and IRL preparations. Only in vitro application of lidocaine was able to ameliorate membrane permeability in smooth muscle of IR and IRL preparations. Lidocaine accumulation could be measured in in vivo treated samples and serum.


CONCLUSIONS
In vivo lidocaine administration during ischemia and reperfusion had beneficial effects on smooth muscle motility. Initiating lidocaine treatment during surgery to treat colic in horses may improve lidocaine's prokinetic features by protecting smooth muscle from effects of ischemia and reperfusion injury.
Department of Physiology, University of Veterinary Medicine, 30173 Hannover, Germany.
Maria
M
Guschlbauer
Karsten
K
Feige
Florian
F
Geburek
Susanne
S
Hoppe
Klaus
K
Hopster
Marcus J
MJ
Pröpsting
Korinna
K
Huber
D000779:Anesthetics, Local / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D003085:Colic / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary; D003402:Creatine Kinase / Q000378:metabolism; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy* / Q000473:pathology; D006736:Horses; D007262:Infusions, Intravenous / Q000662:veterinary; D007537:Isometric Contraction; D007583:Jejunum / Q000187:drug effects / Q000473:pathology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008012:Lidocaine / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D008297:Male; D009130:Muscle, Smooth / Q000098:blood supply / Q000187:drug effects* / Q000473:pathology; D015427:Reperfusion Injury / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*
D000779:Anesthetics, Local; D008012:Lidocaine; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase