The molecule possessing ankyrin-repeats induced by lipopolysaccharide (MAIL) protein is a novel member of the Ikappaβ family. In the present study, we examined the effect of norepinephrine (NE) on MAIL mRNA expression in primary cultured mouse hepatocytes and non-parenchymal liver cells. MAIL mRNA expression in hepatocytes and non-parenchymal liver cells was not directly influenced by NE. However, MAIL mRNA expression in hepatocytes was significantly induced by incubation with a culture medium of non-parenchymal liver cells, treated with NE. Pretreatment with an interleukin (IL)-1 receptor antagonist significantly attenuated the stimulatory effect of the medium. Moreover, exogenous IL-1β induced MAIL mRNA expression in hepatocytes, while IL-6 and tumor necrosis factor α did not. The concentration of IL-1β in the medium of non-parenchymal liver cells was significantly increased after NE-treatment. These results suggest that NE can induce MAIL mRNA expression in hepatocytes through IL-1β, released from non-parenchymal liver cells.

To elucidate the physiological characteristics of histamine receptor of the isolated renal artery in dog, effects of various receptor blockers and Ca++ channel blockers on the contractile responses of histamine were investigated in the isolated renal artery of dog. Histamine caused the contraction in the isolated renal artery of dog, and the contractile responses increased between the concentration of 5 x 10** (-6)M and 10** (-2)M in dose-dependent manner. The contractile response induced by histamine (10** (-3)M) was not blocked by pretreatment with atropine (10** (-6)M), phentolamine (10** (-6)M), propranolol (10** (-6)M) or cimetidine (10** (-6)M), but was completely blocked by pretreatment with pyrilamine (10** (-6)M). The contractility induced by histamine (10** (-3)M) was decreased in the Ca++ free medium. The contractile response induced by histamine (10** (-3)M) was decreased in the Ca++ free medium. The contractility induced by histamine (10** (-3)M) was markedly inhibited by pretreatment with papaverine (5x10** (-5)M) or verapamil (5x10** (-5)M). After the pre-contraction induced by norepinephrine (10** (-7)M) or prostaglandin F2 alpha (5x10** (-6)M), the contractile response induced by the additional treatment of histamine (10** (-3)M) was markedly increased compared with that of histamine (10** (-3)M) alone