Effects of alpha, beta 1, and beta 2 adrenergic antagonists on the Na and K concentrations of sympathetic-nerve stimulated rat saliva.

Selective alpha and beta 1 and beta 2 adrenergic antagonists were used with electrical stimulation of the sympathetic innervation to parotid and submandibular glands of rats in order to delineate the role of the beta 1 and beta 2 adrenoceptors in regulation of salivary flow rate, Na reabsorption and K secretion from these glands. In parotid gland, [Na] of sympathetically evoked saliva in the presence of phentolamine (3 mg/kg, i.p.) was not different from that of nerve-evoked saliva in the presence of phentolamine and butoxamine (3 mg/kg, i.p.), except for the last 20 min of stimulation when [Na] of nerve-elicited saliva was higher. [K] of saliva with sympathetically evoked stimulation was the same in the presence of phentolamine alone as it was or in the presence of phentolamine and butoxamine. Again, there was no difference in salivary flow rate induced by either kind of stimulation, except for the first 10 min of stimulation, during which salivary flow rate of nerve-evoked saliva in the presence of phentolamine was lower than under the other conditions indicated. On the other hand, with submandibular gland, [Na] and [K] of nerve-elicited saliva in the presence of phentolamine were generally higher than levels of sympathetically evoked saliva in the presence of phentolamine and butoxamine. However, salivary flow rate of nerve-evoked saliva in the presence of phentolamine was generally lower than that of sympathetically evoked saliva in the presence of phentolamine and butoxamine.(ABSTRACT TRUNCATED AT 250 WORDS)