taken together , the results suggest that two different populations of beta-adrenergic receptors may co-exist in bat plasma membranes : a small population ( about 15 % ) of atypical beta-receptors and a large population of beta 1-receptors that exhibit high and low affinities for brl 37344 , respectively .
C0007603
plasma membranes
C0001642
beta 1-receptors