Non-specific supersensitivity in rat parotid salivary glands following parasympathectomy

1 The effect of parasympathetic denervation (Px) of the rat parotid salivary glands has been studied. 2 Px produced a significant reduction in wet and dry weight of the parotid gland compared with the intact contralateral control gland. The DNA content per gland was not reduced indicating that cell death had not occurred but that individual cells were smaller. 3 Supersensitivity to both cholinoreceptor and beta-adrenoreceptor stimulation resulted following Px and was observed as a decrease in the threshold dose and an increase in the maximum secretory response. 4 The supersensitivity to beta-adrenoreceptor stimulation was not accompanied by a change in cyclic AMP production but there was an increase in the density of beta-adrenoreceptor binding sites/mg membrane protein. 5 The relationship of this increased density of receptors to the observed supersensitivity is discussed.