Nerve growth factor and an anticomplimentary protease in mouse saliva elicited by nerve stimulation

1. Three substances previously identified in mouse saliva ((1) biologically active nerve growth factor (NGF), (2) a material immunologically identical to the alpha-subunit of 7S-NGF and (3) an anticomplementary protease) were quantified in both mandibular gland saliva and mixed salivary secretions elicited by stimulation of either the sympathetic or parasympathetic nerves to the salivary glands. 2. The concentrations and specific activities of all three substances in pure mandibular saliva equalled or exceeded those found in mixed secretions from all salivary glands. 3. All three substances were found to be primarily secreted as a result of sympathetic rather than parasympathetic nerve stimulation as their concentrations and specific activities were much greater in sympathetic than in parasympathetic mixed salivary secretions. 4. Bioactive NGF, alpha-subunit-like material, and an anticomplementary protease were demonstrated to be released selectively through activation of alpha-adrenergic receptors as the concentrations and specific activities of all three substances were markedly reduced by pre-treatment with an alpha-adrenergic blocker (phenoxybenzamine) but not by pre-treatment with either a muscarinic or a beta-adrenergic blocker (atropine or propranolol, respectively). 5. Measurement of total protein in saliva elicited by sympathetic nerve stimulation following pre-treatment with an alpha-adrenergic, beta-adrenergic, or muscarinic blocking agent demonstrated that proteins other than those examined in the present study must be released by activation of beta-adrenergic receptors.