Effects of adrenergic antagonists on glycoprotein secretion from granular convoluted tubules of the rat submandibular gland induced by methoxamine.:Effects of adrenergic antagonists on glycoprotein secretion from granular convoluted tubules of the rat submandibular gland induced by methoxamine

It is well known that the submandibular gland of the adult rat possesses prominent granular convoluted tubules which lie between the intercalated and striated ducts1) and that the segment has a secretory function. Research combining histological and biochemical analyses of the submandibular gland and saliva following electrical stimulation of autonomic nerves has recently shown that the cells of granular convoluted tubules of rats respond only to ƒ¿-sympathetic stimulation2). In previously performed micro-electrophoretic analyses of parenchymal components dissociated from the submandibular gland of nor mal adult rats using a microdissection method3) devised by us, we found that granular convoluted tubules contain characteristic glycoprotein species which differ greatly from acini, striated ducts and excretory ducts3) these species are secreted into saliva in a manner dependent on the salivary flow rate when an ƒ¿1adrenergic agonist, methoxamine, is administered at a relatively high dose4). The present study was carried out using the ƒ¿1-antagonist prazosin, the ƒ¿2-antagonist