Beta adrenergic and muscarinic receptor densities of rat submandibular main duct.
[3H]DHA binding studies show that main duct of rat submandibular gland has both beta 1 and beta 2 adrenoceptors, with the percentages of each being 69 and 31%, respectively, whereas whole submandibular gland has 90% beta 1 and 10% beta 2 adrenoceptors. Muscarinic receptors of main duct are 25% less than that of whole submandibular gland.