Electrical stimulation of the parasympathetic
auriculo-temporal nerve (40 Hz, 30 min), in the
anaesthetized rat under α- and β-adrenoceptor
blockade, increased [3H]thymidine and [3H]leucine
uptake into the parotid glands by 80 and 263 %, respectively. The
increase in response to parasympathetic stimulation was almost the
same ([3H]thymidine 82 % and [3H]leucine 283 %) when atropine (2
mg kg-1 I.P. or I.V.) was included in the pretreatment. Neither
intravenous infusion of vasoactive intestinal peptide (0.5-20 mg kg-1
min-1, 30 min) nor of bethanechol (10 mg kg-1 min-1, 30 min), under
adrenoceptor blockade, increased the uptake of [3H]thymidine into the
glands. However, these drugs increased [3H]leucine uptake, and in
combination they interacted positively. Whereas vasoactive intestinal
peptide is likely to be involved in the parasympathetic nerve-evoked
protein synthesis, the nature of the non-adrenergic, non-cholinergic
component(s) involved in the mitogenic response is presently unknown.