CHARACTERIZATION OF BETA-ADRENERGIC RECEPTORS ON RAT AND HUMAN OSTEOBLAST-LIKE CELLS AND DEMONSTRATION THAT BETA-RECEPTOR AGONISTS CAN STIMULATE BONE-RESORPTION IN ORGAN-CULTURE
Re. Moore et al., CHARACTERIZATION OF BETA-ADRENERGIC RECEPTORS ON RAT AND HUMAN OSTEOBLAST-LIKE CELLS AND DEMONSTRATION THAT BETA-RECEPTOR AGONISTS CAN STIMULATE BONE-RESORPTION IN ORGAN-CULTURE, Bone and mineral, 23(3), 1993, pp. 301-315
We have shown by receptor-binding analyses that the beta-2 adrenergic
receptor is present on rat ROS 17/2.8 osteoblast-like cells. This was
confirmed by PCR amplification of cDNA copied from the mRNA. The beta-
1 adrenoreceptor subtype was absent and its mRNA was not detectable, e
ven at the level of sensitivity afforded by PCR analysis. The beta-adr
energic receptors present on ROS 17/2.8 cells were functional as measu
red by ligand-induced enhancement of cAMP production. We investigated
whether adrenergic agonists could mimic the action of PTH to stimulate
bone resorption in neonatal mouse calvariae in organ culture. PTH ind
uced a large increase in cAMP while norepinephrine and isoproterenol i
nduced a small but significant increase. In the presence of a phosphod
iesterase inhibitor and an antioxidant, norepinephrine consistently st
imulated bone resorption. In order to determine whether functional bet
a-adrenergic receptors were unique to ROS 17/2.8 cells, human SaOS-2 o
steoblast-like cells were also examined for enhancement of cAMP produc
tion by norepinephrine, and essentially the same results were obtained
. Thus, adrenergic agonists efficiently activate beta-receptors on two
osteoblast-like cells and can stimulate bone resorption in intact mou
se calvariae.