A method to evaluate lymphatic drainage of macromolecular tracer in cerebrospinal fluid / 中国药理学通报

ABSTRACT

Aim To establish a method to evaluate lymphatic drainage of macromolecular tracer in cerebrospinal fluid in rats.Methods Rat cervical lymphatic blockade(CLB)models were established by occlusion of cervical lymphatic tubes and removal of cervical lymphatic nodes.The rats were divided into non CLB(normal controls) and CLB groups.~(125)I-labeled human serum albumin(~(125)I-HSA)was injected into the left lateral cerebral ventricle,and blood samples were collected and ~(125)I-HSA concentrations were detected continually within 24 hours.Concentration-time curve was drawn according to the single compartment model in pharmacokinetics.Parameters of pharmacokinetics such as area under curve(AUC),maximum concentration(C_(max)),transfer rate constant K_a and peak time(T_(max))were derived.The AUC,C_(max),K_a,and T_(max) regarding the lymphatic drainage of ~(125)I-HSA were calculated based on the differences between the two groups.Results AUC,C_(max),K_a of ~(125)I-HSA by lymphatic drainage were 51.97 mg·L~(-1)·h~(-1),2.91 mg·L~(-1),and 0.64 h~(-1),respectively.The proportion of AUC,C_(max),K_a of ~(125)I-HSA by lymphatic drainage to those of drained by both arachnoid granulations and lymphatics was 71.53%,44.02%,58.18%,respectively.T_(max) in CLB group(8.36±0.82 h)was much longer than that in non CLB group(3.57±0.54 h).Conclusions A method to evaluate lymphatic drainage of macromolecular tracer in cerebrospinal fluid in rats is successfully established.The lymphatic drainage pathway plays an important role in eliminating macromolecular substances in cerebrospinal fluid.