ATKINS E, WOOD W B
J Exp Med. 1955 May 1;101(5):519-28. doi: 10.1084/jem.101.5.519.
The rate of clearance of intravenously injected typhoid vaccine was studied in unsensitized, sensitized, and pyrogen-tolerant rabbits by means of a passive transfer technique. The blood of unsensitized rabbits which had not been previously exposed to bacterial pyrogen remained pyrogenic for normal recipients throughout a period of 2 hours following the injection. In contrast, rabbits sensitized by having received either one or two injections of the vaccine at least 3 weeks prior to the experiment cleared their blood of the test vaccine within 30 minutes despite the fact that they exhibit the same febrile response as unsensitized rabbits. After 1 hour, however, a transferable pyrogenic substance was again demonstrable in the sera of this group. Reasons are discussed for believing that this newly appearing substance may be of endogenous origin and may be the factor which directly affects the thermoregulatory centers of the brain. Rabbits which are made tolerant by repeated daily injections of vaccine have a characteristically depressed febrile response. Not only were the blood streams of such animals cleared of the injected vaccine within less than 5 minutes, but samples of their sera obtained 1 and 2 hours after the injection also failed to contain demonstrable quantities of the secondary pyrogen observed in sensitized animals. The latter observation is in keeping with the suggestion that the secondary pyrogen may play a critical role in the production of fever.
采用被动转移技术，对未致敏、致敏和热原耐受的家兔静脉注射伤寒疫苗后的清除率进行了研究。未接触过细菌热原的未致敏家兔的血液，在注射后2小时内，对正常受体仍具有致热作用。相比之下，在实验前至少3周接受过一次或两次疫苗注射而致敏的家兔，尽管它们表现出与未致敏家兔相同的发热反应，但在30分钟内就清除了血液中的试验疫苗。然而，1小时后，该组家兔血清中又可检测到一种可转移的致热物质。文中讨论了认为这种新出现的物质可能起源于内源性且可能是直接影响脑体温调节中枢的因素的原因。通过每天重复注射疫苗而产生耐受性的家兔，其发热反应明显受到抑制。这类动物不仅在不到5分钟内就清除了血液中的注射疫苗，而且在注射后1小时和2小时采集的血清样本中也未检测到致敏动物中观察到的可检测量的二次热原。后一观察结果与二次热原可能在发热产生中起关键作用的观点一致。
