[The mechanism and significance of cellular signal transduction in kidney glomerular mesangial cells of rat with obstructive jaundice].

OBJECTIVE: To study the mechanism of ceramide-induced cellular signal transduction and its effect on renal injury. METHODS: Sixty male Sprague-Dawley rats were randomly assigned to four groups (n = 15): control group, sham operation group, experiment group one and experiment group two. Except the control and the sham operation group, the other two experiment groups underwent the common bile duct bound to form the rat model of obstructive jaundice. The renal glomerular mesangial cells (GMC) were cultured primarily. After GMC were given different stimulating factors, we performed the measurement of the PLD activity and the GMC apoptosis analyzed by flow cytometry. RESULTS: The biological activity of PC-PLD was significantly decreased by TNF-alpha and ceramide (P< 0.05). On the other hand, the GMC apoptosis was induced by TNF-alpha and ceramide (P <0. 05). However, other opposite results were obtained in addition of ceramide inhibitor to GMC. CONCLUSION: TNF-alpha can induce the ceramide increase in GMC, which is significant to effect on the kidney injury of the rats with obstructive jaundice, by the means of inducing GMC apoptosis and decreasing the activity of PC-PLD.

[Changes of mitochondrial membrane potential (delta psi m) and calcium concentration in cultured glomerular mesangial cells of rats with obstructive jaundice].

OBJECTIVE: To explore the effect of mitochondrial membrane potential (delta psi m) and calcium concentration on the kidney injury of rats with obstructive jaundice and to probe into the underlying mechanism. METHODS: Sixty male Sprague-Dowley rats, weighing 200 g to 250 g were randomly divided into three groups: control group; sham operation group; experiment group. And the rats of experiment group were subdivided into two groups according to the time (15 d, 21 d) after the common bile duct ligation. The experiment groups were rendered jaundiced by doubly ligating the common bile duct. Glomeruli were isolated, the glomerular mesangial cells (GMCs) were cultured. The mitochondrial membrane potential (delta psi m) was measured by flow cytometry; the concentration of calcium was measured by confocal microscopes. RESULTS: The amount of mitochondrial membrane potential (delta psi m) was decreased (P < 0.05) in the rats with obstructive jaundice, compared with the control; the concentration of calcium was increased (P < 0.05) in the rats with obstructive jaundice, compared with the control. Conclusion The calcium incurrent that leads to changes in amount of mitochondrial membrane potential (delta psi m) has significant effect on the kidney injury of the rats with obstructive jaundice.