Stress response to surgical procedures in the submandibular region and its influence on salivary secretion in mice

Saliva stimulated by pilocarpine was collected from the mouths of adult ICR male mice after either submandibular–sublingual gland (SM–SL) exposure and SM–SL removal under pentobarbital anaesthesia. Salivary flow rates decreased and salivary protein concentrations increased after both surgical procedures. Serum cortisol was elevated after the operations. Salivary protein separation patterns on sodium dodecylsulphate–polyacrylamide gel electrophoresis (SDS–PAGE) from surgically treated animals were very similar to those from mice given an α1-adrenergic agonist (phenylephrine), but differed significantly from those given a β-adrenergic agonist (isoproterenol). When the SM–SL was completely removed (i.e. parotid saliva), protein concentrations also dramatically increased. The SDS–PAGE protein separation pattern in the mice whose SM–SL had been removed was very similar to that in those whose SM–SL had been exposed. Hence, a surgical insult in the submandibular region in mice enhances the secretion of salivary protein, mainly in response to α1-adrenergic receptor stimulation in the parotid gland. This study suggests the usefulness of α1-adrenergic receptor-stimulated parotid salivary protein as a marker of surgical insult.