In vivo stimulation of sympathetic nervous system modulates osteoblastic activity in XXXX calvaria.

@entity1 @entity650 @entity1169 @entity19 @entity1425 @entity5521 @entity777 @entity3044 @entity1063 @entity2955
Previously, we demonstrated that @entity1425 induced the expression of @entity650 mRNA via beta-adrenoceptors in cultured @entity1 osteoblastic cells. @entity777 is well known to modulate bone metabolism by regulating the development and function of osteoclasts and osteoblasts. Recently, restraint stress and intracerebroventricular injection of lipopolysaccharide (LPS) have been reported to induce the expression of @entity777 mRNA in peripheral organs in @entity19 in which expression is mediated by the activation of the sympathetic nervous system. To prove the physiological role of sympathetic nerves in bone metabolism in vivo, we examined by RT-PCR analysis the effects of restraint stress and intracerebroventricular injection of LPS on @entity777 mRNA expression in @entity19 calvaria. The expression of @entity777 mRNA in @entity19 calvaria was stimulated by either restraint stress (30 min) or intracerebroventricular injection of LPS (50 ng/ @entity19 , 60 min). The treatment of @entity19 with the neurotoxin @entity2955 ( @entity2955 , 100 mg x kg-1 x day-1 ip for 3 days) inhibited LPS (icv)-induced expression of @entity777 mRNA in their calvaria. The expression of @entity777 mRNA induced by the restraint stress was not influenced by @entity2955 , which destroys noradrenergic nerve terminals. Furthermore, pretreatment with a beta-blocker, @entity1169 (15 or 25 mg/kg ip), inhibited both stress- and LPS-induced increases in the level of @entity777 mRNA, but pretreatment with an alpha-blocker, @entity5521 (5 mg/kg sc), did not inhibit them in @entity19 calvaria. In addition, treatment of calvaria with @entity3044 or @entity1063 increased @entity777 synthesis in the organ culture system. These results indicate that in vivo adrenergic stimulation modulates the osteoblastic activity in @entity19 calvaria via noradrenergic nerve terminals.
