Abstract
The 30-min brain uptake of [125I]HIPDM was measured in conscious rats--normocapnic (n = 8), hypercapnic (n = 12), and hyperoxic (n = 6). A mean 41.2% higher uptake was found in the brains of hypercapnic animals (p less than 0.01). In the three groups of rats, brain HIPDM uptake had a negative correlation with body weight (p less than 0.001) and a positive correlation with arterial pCO2 (p less than 0.01), when adjusted for body weight. These results indicate that HIPDM uptake with hypercapnia may be used as a provocative test to measure cerebral blood flow reserves.
