ALTERED CONTROL OF VENTILATION IN STREPTOZOTOCIN-INDUCED DIABETIC RATS

The purposes of this study were (i) to determine if ventilatory contro l is altered In streptozotocin (STZ)-induced diabetic rats and (ii) to determine whether insulin treatment of diabetic rats could prevent ve ntilatory abnormalities. Male Sprague Dawley rats were randomly assign ed to three groups: control (n = 10), diabetic (n = 9), and diabetic t reated with insulin (n = 9). The diabetic group exhibited a progressiv e reduction of tidal volume, minute ventilation, and CO2 production co mpared with the control and diabetic treated with insulin groups over the 4 week period. Furthermore, the ventilatory responses to the hyper capnic (3%, 6%, 9% CO2) and hypoxic (10% O-2) gas challenges were sign ificantly less in the diabetic rats than those of the control and diab etic and insulin treated groups by the third and fourth week. Ventilat ion and ventilatory responses to hypercapnia and hypoxia were similar in the control group and the diabetic treated with insulin group at th e end of the study. In conclusion, uncontrolled diabetes induced in ra ts by STZ treatment resulted in altered control of ventilation that co uld be prevented by insulin therapy.