Postnatal developmental changes in blood flow to choroid plexuses and cerebral cortex of the rat

Postnatal developmental changes in blood flow to choroid plexuses of the lateral (LVCP) and fourth (4VCP) ventricles and cerebral cortex were studied in pentobarbital-anesthetized rats at 2, 3, 5, and 7-8 wk. Blood flow was measured by indicator fractionation with N-isopropyl-p-[125I]iodoamphetamine as the marker. Blood flow to the LVCP and 4VCP was 2.5 +/- 0.1 and 2.7 +/- 0.1 ml.g-1.min-1, respectively, and did not change between the 2nd and 3rd wk. However, it increased by 34% between the 3rd and 5th wk. From the age of 5 wk on, 4VCP was characterized by higher blood flow rates than LVCP. Cerebral cortical blood flow gradually increased between the 2nd and 5th wk. There was no difference in cortical blood flow between 5-wk-old and adult animals. The changes in choroidal blood flow likely represent a continuing adjustment of the choroidal vascular system to steadily increasing secretory capabilities of the maturing choroidal epithelium.