Effects of 3‘, 5’‐Cyclic Adenosine Monophosphate, 5‐Hydroxy‐tryptamine, Noradrenaline and Theophylline on the Simultaneous Release of Peroxidase and Amylase from the Guinea Pig Submanibular Gland

Noradrenaline (NA), 5‐hydroxytryptamine (5‐HT) and N 6 ,2‐0′‐dibutyryl cyclic adenosine monophosphate (DBcAMP) induced a parallel discharge of peroxidase and amylase from the guinea pig submandibular gland in vitro. Theophylline alone, at a concentration of 5 mM, had only little effect on enzyme secretion, but it markedly potentiated the effects of noradrenaline, 5‐HT and DBcAMP at submaximal concentrations. Adenosine‐3′‐monophosphoric acid (3′‐AMP) and adenosine‐5′‐monophosphoric acid (5′‐AMP) were without effect on enzyme secretion. Maximal effects of NA and DBcAMP on enzyme release were obtained at concentrations of 0.01 mM and 3 mM respectively. Dose‐response curves for the stimulation of peroxidase and amylase release by 5‐HT revealed that this amine was a potent secretagogue at the concentrations of 0.1 and 0.3 mM but was less effective at higher concentrations. It is concluded that peroxidase and amylase are simultaneously secreted from the guinea pig submandibular gland, and that the release of both enzymes is mediated via cyclic AMP.