<正> The effects of chronic hypoxia on calmodulin levels of lung tissues and small pulmonary ar-terial walls were studied in young pigs

The tissue specimens of hypoxic animals were obtained underhypoxic conditions. The following results were collected:（1） The swine exposed to chronic intermittent hypoxia showed a significant pulmonary pressor re-sponse at a simulated high altitude of 4000 m.（2） A higher level of calmodulin was found in the lung tissues of chronic hypoxic animals. It maybe related to the increased release of some vaosactive substances from pulmonary non-muscularcalls.（3） No significant difference of calmodulin level of small arterial walls was demonstrated between theexperimental animals and the control.The findings suggest that pulmonary vasoconstriction due to hypoxia is not likely to be associatedwith obvious change in calmodulin level in the smooth muscle of blood vessels.