Abstract
Summary
Calcium levels of rat parotid saliva evoked by stimulation of the auriculotemporal nerve are high (11 mEq/1) and in fact, higher than those evoked by stimulation of the sympathetic innervation. Total calcium output in the cholinergically-evoked saliva is also very high but the depletion of gland levels is insignificant 20 or even 60 min after the initiation of stimulation. With sympathetic stimulation, there is a closer correlation between gland depletion and total output of calcium in the saliva. These findings suggest that the uptake mechanism for calcium with cholinergic stimulation is more rapid than that found with adrenergic stimulation. The high levels of calcium in the cholinergically evoked saliva are also not due to acetylcho-line-induced release of catecholamines since calcium levels of cholinergically-evoked saliva are the same whether or not adrenergic blocking agents are present. The total output of amylase in the saliva when sympathetic stimulation is employed is about five times greater than that found with cholinergic stimulation, and the reduction in gland amylase under these two conditions of stimulation reflect these same relations. The data also show that there is a parallelism between depletion of gland amylase and calcium and concentration and total output of these two moieties in the saliva when adrenergic stimulation is used but that no parallelism between secretion of these substances is seen with cholinergic stimulation. It is suggested that with adrenergic stimulation all of the amylase is packaged together with calcium and the two are secreted together; however, with cholinergic stimulation, only a fraction of the total calcium is packaged with the amylase, and the remainder is transferred from blood through the gland to the saliva. Thus, two separate routes for secretion of calcium exist with cholinergic stimulation, and the pathways with the two kinds of nerve stimulation are different.
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