Study on blood-brain-barrier. I

Flowing by physiological salt solution from the a. carotis interna to the v. jugularis externa of dogs, we studied B.B.B. from the stand point of physiology as well as chemistry, with anorganic phosphor (amino-naphthol sulfonic acidmethod), Calcium (Yanagisawas method) and Chlor (Sharles-Shales method) in tracing with I ^131 and Lu＾117 . We gained the following results： 1) When convecting pressure is 160 cm H_2 O, changes in the flowing volume relatively increased by tracing with isotopes, but at 200 cm H_2 O, we observed very little change. 2) Exceration of isotope from the v. jugularis externa shows large peaks after 2-3 minutes from the beginning of tracing. The opposit side is slower. 3) Change in chlor, calcium and anorganic phosphor is observed, but is not peculiar. We think that calcium and anorganic phosphor go into brain and cerebrospinal fluid after convection is decreased. 4) In spite of the fact that carotic artery is bound, isotope is taken from the fluid of the opposite side of the vein.