摘要
AIM: To determine platelet activating factor (PAF) receptor expression in cirrhotic hepatic stellate cells.METHODS: Hepatic stellate cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium after overnight culture. We determined the PAF receptor in hepatic stellate cells by saturation binding technique and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and the effects of PAF and its antagonist BN52021 on prostaglandin E2 (PGE2) release by stellate cells.RESULTS: Scatchard analysis indicated the presence of PAF receptor with dissociation constant (Kd) of 4.66 nmol/L and maximum binding capacity (Bmax) of 24.65 fmol/μg in cirrhotic stellate cells. Compared with the control, the maximum PAF binding capacity increased significantly (Bmax: 24.65 ± 1.96 fmol/μg. DNA, R = 0.982 vs 5.74 ± 1.55 fmol/μg. DNA, R = 0.93; P < 0.01), whereas receptor affinity had no significant difference (Kd of 4.66 ± 0.33 nmol/L for the cirrhosis and 3.51 ± 0.26 nmol/L for the control; P > 0.05). Consistent with the receptor binding data, the mRNA expression of PAF receptor was increased significantly in cirrhotic stellate cells. PAF in a concentration-dependent manner induced PGE2 synthesis in cirrhotic hepatic stellate cells, but the effects were blocked significantly by BN52021.CONCLUSION: Cirrhosis sensitizes hepatic stellate cells to PAF by elevating its receptor level and hepatic stellate cells maybe potential effectors of PAF induced portal hypertension.
AIM： To determine platelet activating factor （PAF） receptor expression in cirrhotic hepatic stellate cells. METHODS： Hepatic stellate cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium after overnight culture. We determined the PAF receptor in hepatic stellate cells by saturation binding technique and semiquantitative reverse transcriptase polymerase chain reaction （RT-PCR）, and the effects of PAF and its antagonist BN52021 on prostaglandin E2 （PGE2） release by stellate cells. RESULTS： Scatchard analysis indicated the presence of PAF receptor with dissociation constant （Kd） of 4.66 nmol/L and maximum binding capacity （Bmax） of 24.65 fmol/μg in cirrhotic stellate cells. Compared with the control, the maximum PAF binding capacity increased significantly （Bmax： 24.65 ± 1.96 fmol/μg. DNA, R = 0.982 vs 5.74 ± 1.55 fmol/μg. DNA, R = 0.93; P 〈 0.01）, whereas receptor affinity had no significant difference （Kd of 4.66 ± 0.33 nmol/L for the cirrhosis and 3.51 ± 0.26 nmol/L for the control; P 〉 0.05）. Consistent with the receptor binding data, the mRNA expression of PAF receptor was increased significantly in cirrhotic stellate cells. PAF in a concentration-dependent manner induced PGE2 synthesis in cirrhotic hepatic stellate cells, but the effects were blocked significantly by BN52021. CONCLUSION： Cirrhosis sensitizes hepatic stellate cells to PAF by elevating its receptor level and hepatic stellate cells maybe potential effectors of PAF induced portal hypertension.
基金
The Key Scientific and Technological ResearchFoundation of the National 863 Program, No. 2003AA208106
Medical Outstandard Foundation of Army, No. 04J020
