Immediate and delayed effects of hypobaric hypoxia during early postnatal period on the functioning of digestive enzymes

Impact of airplane cabin pressure on biliary motility in rabbits

AIM: To observe the effect of the change in barometric pressure on biliary motility by using a hypobaric chamber to simulate a civil aircraft in flight.

METHODS: Forty-two rabbits were randomly divided into a control group (n = 14), a Ta group (n = 14, hypobaric exposure in a hypobaric chamber 3 times in 3 d) and a Tb group (n = 14, hypobaric exposure in a hypobaric chamber 7 times in 7 d). The level of cholecystokinin 8 (CCK8) was measured in the duodenal tissue and plasma. The expression of CCK-A receptor (CCK-AR) mRNA in gallbladder tissues was detected by RT-PCR. Quantitative analysis of 99mTc-EHIDA hepatobiliary dynamic imaging was made in each group.

RESULTS: Compared to the control group, the Ta group had lower levels of CCK8 both in duodenal tissue and plasma (Ta group vs C group, 5.24 pg/mL ± 0.56 pg/mL vs 6.25 pg/mL ± 0.53 pg/mL in duodenal tissue, P < 0.05; 3.59 pg/mL ± 0.20 pg/mL vs 4.61 pg/mL ± 0.10 pg/mL in plasma, P < 0.05) and a significant delay in duodenal appearance time (Ta group vs C group, 114.73 s ± 13.34 s vs 79.52 s ± 10.83 s, P < 0.05). Besides a delay in DAT and lower level of CCK8, decreased expression of CCK-A receptor mRNA was found in gallbladder tissues in the Tb group compared to the control group and Ta group (CCK-AR/β-actin: Tb group vs C group: 0.56 ± 0.21 vs 0.82 ± 0.16, P < 0.05; Tb group vs Ta group: 0.56 ± 0.21 vs 0.75 ± 0.29, P < 0.05).

CONCLUSION: Barometric pressure change in a civil aircraft in flight shows some inhibitory effects on biliary motility.