Aim: 

The role of bombesin (BN) in bile formation is not clear yet. The goal of this research was to determine the effect of BN on secretion of bile lipid components.

Methods: 

Investigations were conducted on white male rats 180-200 g in acute experiment. BN (Sigma, USA) in dose 1 mg/100 g b, i.v., and atropine in dose 0.2 mg/100 g, i.p. were administered. The output of bile lipids was measured by thin-layer chromatography.

Results: 

BN increased the output of phospholipids (+64.2%; p > 0,05), cholesterol (1.57 mg/g to 3.37 mg/g; p < 0.01), its esters (0.18 mg/g to 0.43 mg/g; p > 0,05), and free fatty acids (+70%; p < 0.05) on the ground of decreasing of triglycerides amount. At the same time the cholate-cholesterol ratio (CCR) was reduced, the cholesterol -to its esters ratio was elevated. The phospholipids-cholesterol ratio (PCR) was diminished. The potent cholesterol crystallization index (PCCI) was not higher than 7%. Peptide administration after previously injected atropine caused the significant reduction of all biliary lipids comparatively to the administration of BN alone. It was followed by decreasing of CCR and cholesterol -to its esters ratio. But the PCR elevated (from 2.63 to 3.34). The PCCI had a tendency to grow.

Conclusions: 

Obtained data show that effect of BN on phospholipid, cholesterol and its esters biliary secretion depends on the activity of M-acetylcholine receptors. After administration of BN the PCCI stays at normal rate; cytotoxic effect of bile acids is diminished due to enhancing secretion of phospholipids into bile; solubilisation properties of bile are improved.