Release of kallikrein-like esterase and tonin from dispersed cells of the rat submandibular gland.

Viable dispersed cell preparations of rat submandibular gland were obtained by a tissue-dissociation procedure using collagenase and gentle mechanical force. The cells released kallikrein-like esterase in a time- and calcium-dependent manner in response to noradrenaline (10 microM) at 30 degrees C. The net loss of kallikrein-like esterase content from the dispersed cells corresponded with the increase in kallikrein-like esterase activity in the suspending medium at all concentrations of noradrenaline. These results indicate the viability and functional integrity of this dispersed cell preparation of rat submandibular gland. alpha-Adrenoceptor agonists such as noradrenaline stimulated kallikrein-like esterase and tonin release in a dose-dependent manner, whereas the beta-adrenoceptor agonist isoprenaline and cholinoceptor agonist methacoline were both inactive. Noradrenaline-induced release of kallikrein-like esterase and tonin were completely blocked by prior addition of the alpha-adrenoceptor antagonist, phenoxybenzamine. It is concluded that the secretion of kallikrein-like esterase and tonin in rat submandibular gland is mediated only via stimulation of alpha-adrenoceptors.