[Effect of dopamine on the sensitivity of carotid body to hypoxia induced by acute intermittent hypoxia in rats].

Objective

To investigate the sensitivity of carotid body to hypoxia and the effect of dopamine on the sensitivity of carotid body to hypoxia after acute intermittent hypoxia stimulation in rats.

Methods

The isolated carotid body-sinus nerve in rat was transferred to incubator, and then the isolated sinus nerve was inhaled into the recorded glass electrode for recording electrical signals. The baseline buffer was bubbled with 95% O 2 + 5% CO 2 mixture gas, and the hypoxic stress was treated with 5% O 2 + 5% CO 2 + 90% N2 mixture gas, hypoxic stimulation was given for 30 seconds, 95% O 2 + 5% CO 2 for 90 seconds, a total of 10 cycles. No less than 5 rats in each group.

Results

In this experiment, the electrical activity of sinus nerve isolated from rats was enhanced by hypoxia stimulation after acute intermittent hypoxia, but the response of sinus nerve to hypoxia was inhibited by dopamine. Before acute intermittent hypoxic stress, dopamine also inhibited the firing activity of sinus nerve, but after acute intermittent hypoxic cycle, the inhibition of dopamine on the firing activity of sinus nerve was strengthened.

Conclusion

Acute intermittent hypoxia enhances the response of sinus nerve isolated from rats to hypoxia, dopamine inhibits the enhancement of carotid body sensitivity to hypoxia induced by acute intermittent hypoxic.