title: A new in vivo method for quantitatively evaluating local anesthetics.
abstract: A method utilizing the reflex contraction of the retractor muscle of the hamster cheek pouch was developed to evaluate onset and duration of blockade produced by a local anesthetic agent infiltrated into or absorbed through the pouch epithelium. It provides a quantitative measure of reflex tension developed by the muscle as a function of afferent nerve conductivity in the pouch. The method is based upon the fact that when the pouch is everted activation of the retractor muscle results in the pouch being pulled toward the oral cavity. The method was validated by comparing the results with those obtained with other animal models and clinical trials. Ketocaine, an experimental drug, was evaluated for its efficacy as a local anesthetic when administered topically. In its present formulation the long latency of onset of blockade renders it impractical for clinical use.
mesh_terms: D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D006224:Cricetinae; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004558:Electric Stimulation; D004837:Epinephrine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009431:Neural Conduction / Q000187:drug effects; D013997:Time Factors
chemical_list: D000779:Anesthetics, Local; D004837:Epinephrine