Abstract
Physico-chemical properties of the cerebrospinal fluid (CSF) drawn from a rabbit after the i.v. injection of thyphoid vaccine were studied. Results are as follows: When the CSF, obtained from the rabbit to which thyphoid vaccine had been given i.v., was intracerebrally injected into other rabbits, pyrogenecity was observed. Pyrogenecity of the CSF was inactivated by the addition of deoxycholate (DOC) and was reversed by dialysis or dilution with water. DOC showed no effect on the pyrogenecity of leucocytic pyrogen. Lipopolysaccharide (LPS) could be divided into several groups of molecular weights utilizing membrane filters. The LPS with higher molecular weights also shows high pyrogenecity with i.v. administration, and the molecular weights causing a similar activity when administrated intracerebrally ranged from 5.0 × 104 to 105. From these data, it is suggested that pyrogenecity of the CSF from febrile rabbits may be due to the LPS derived from the peripheral blood.
