Experimental studies on blood-spinal fluid barrier

Although many investigations concerning blood-spinal fluid barrier have been reported up to date, none of them have presented a clear convincing explanation of this problem even in these days when radioactive isotopes have been employed for experiments. Since Walters report, I think, many important and fundamental problems for these experiments such as concentration rate of bromide in blood and the time from bromide injection into blood until its discovery in spinal fluids, has not been clarified yet. Further, the bromide method by Walter takes several days for bromide administration, therefore, for various experimental studies on acute intracranial injuries, it is thought to be very important to investigate the altitude of blood-spinal fluid barrier when bromide is injected into blood within short time. I have investigated these problems by a rapid administration method of bromide, namely injecting 2% CaBr_2 solution intravenously, and also the effects of hyaluronidase which have been injected intravenously, or into subarachnoid space simultaneous with bromide injection. The following results were obtained. 1. No significant bromide was found normally in blood and spinal fluid.