A modified method for quantitative measurements of cholinergic and adrenergic sialogogue-induced salivation in mice

A modified procedure based on that reported by Richter is described for the quantitative measurement of salivation induced by sialogogues in mice. As a new immobilizing technique for mice, the present method uses a combination of light anesthesia produced by a low dose (1.0 g/kg, i.p.) of urethane and a fixing plate, instead of deep anesthesia induced by a high dose (1.8 g/kg, i.p.) of urethane. Unlike Richter's method, the immobilizing technique described here did not potentiate the toxicity of sialogogues and hence no mice died within 48 h after the end of the experiment. This method could easily measure salivation induced by cholinergic agonists (pilocarpine and bethanechol) and adrenergic agonists (phenylephrine and isoproterenol), dose-dependently. Thus, the present method may be useful for studying salivation responses induced by various types of sialogogues under less toxic experimental conditions in mice.