Is fever really a "side-effect" of biological response modifiers?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30202/1/0000590.pd

Interleukin-1: The Pros and Cons of Its Clinical Relevance

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75148/1/j.1525-1594.1988.tb02759.x.pd

Altered thermoregulation in the iguana disposaurus dorsalis following exercise

1. 1.|Seven desert iguanas ran on a motorized treadmill for 20-min periods. Before, during and after exercise, the iguanas were in a thermal gradient which allowed them to thermoregulate behaviourally.2. 2.|For several hours following exercise, the iguanas selected warmer ambient temperatures, resulting in small, but statistically significant, increases in body temperature.3. 3.|The increases in temperature were proportional to the exercise intensity.4. 4.|These changes were not observed if exercised was preceded by administration of the antipyretic drug, sodium salicylate.5. 5.|These data support the hypothesis that exercise causes a change in central thermoregulatory control which may be similar to fever caused by infection.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25757/1/0000318.pd

Oxygen uptake in green iguana (Iguana iguana) injected with bacteria

1. 1.|Green iguanas (I. iguana) were maintained at a constant body temperature of 35.5[deg]C and injected with either saline or a dose of bacteria which had been previously shown to induce a fever by 3 h post-injection.2. 2.|There were no significant differences in the oxygen uptake between the lizards injected with saline and bacteria.3. 3.|We conclude that green iguanas do not increase their internal heat production as an effector response to the raised thermoregulatory "set-point" that occurs during fever.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23593/1/0000555.pd

Electroconvulsive Therapy Increases Plasma Levels of Interleukin-6 a

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74956/1/j.1749-6632.1990.tb40529.x.pd

Effects of chronic infusion of lipopolysaccharide on food intake and body temperature of the rat

Unrestrained male Sprague-Dawley rats were infused for seven days with a low (2.45 [mu]g/hr) or high (9.81 [mu]g/hr) concentration of E. coli lipopolysaccharide (LPS). Compared to control (saline-infused) rats, food intake in the LPS-infused rats remained depressed for the entire infusion period. Despite this long-term suppression of food intake, fever was observed only during the daytime hours for the first two days of infusion. No significant increase in nighttime body temperature was observed. These data indicate that although tolerance to LPS occurred in rats with regard to its fever-inducing effect, tolerance with respect to its anorexigenic action did not occur.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27525/1/0000569.pd

Polymyxin B use does not ensure endotoxin-free solution

Polymyxin B is often added to in vitro samples to `ensure' that endotoxin activity is removed. We present data, from the standard rabbit pyrogen test and the Limulus amebocyte lysate assay, that polymyxin B bound to a gel support will bind some, but not all, endotoxin. These data, in conjunction with previously published data by Morrison and Curry (1979), indicate that those studies that have relied on polymyxin B to inactivate endotoxin must be re-evaluated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25529/1/0000070.pd

Stress-induced rise of body temperature in rats is the same in warm and cool environments

Several forms of psychological stress result in a rise in body temperature in rats. In this study, we report that rats housed at a low ambient temperature (11.1[deg]C) develop stress-induced rises in body temperature that do not differ from the responses seen when the animals are kept at a temperature within their thermoneutral zone (24.7[deg]C). These data support the hypothesis that stress-induced "hyperthermia" is a regulated rise in temperature (i.e., a rise in thermoregulatory "set-point," or fever), and is not simply the result of metabolic changes associated with the stress response itself.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28659/1/0000476.pd

The effects of pentoxifylline on lipopolysaccharide (LPS) fever, plasma interleukin 6 (IL 6), and tumor necrosis factor (TNF) in the rat

The purpose of these studies was to test whether pentoxifylline, a drug that can inhibit the production and action of cytokines hypothesized to be endogenous pyrogens (for example, interleukin 1 and tumor necrosis factor [TNF]), is antipyretic. We also tested the effects of pentoxifylline on plasma activities of interleukin 6 (IL 6) and TNF in response to an injection of a fever-inducing dose of lipopolysaccharide (LPS). Our results showed that a high dose of pentoxifylline (200 mg/kg) caused hypothermia in control rats and blocked LPS fever, while a low dose (50 mg/kg) did not have these effects. Injection of the high dose of pentoxifylline in control rats caused a rise in plasma IL 6 but not in plasma TNF. However, the peak levels of plasma IL 6 and TNF activities following an injection of LPS were significantly reduced by pretreatment with pentoxifylline. Overall, the data are consistent with the hypothesis that pentoxifylline is an antipyretic drug, which may act at least in part by inhibiting the secretion of pyrogenic cytokines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28504/1/0000301.pd

Effect of centrally administered interleukin-1 and endotoxin on food intake of fasted rats

We have previously shown that interleukin-1 (IL-1), a polypeptide known to mediate many aspects of the acute phase response to infection, suppresses food intake when injected intraperitoneally into fasted rats. IL-1 acts at the level of the hypothalamus to induce fever. In view of the large number of peptides that have been shown to alter food intake as well as body temperature when injected intracerebroventricularly (ICV), we hypothesized that the receptor site for the anorexigenic activity of IL-1 would be located in a central nervous site bathed by the cerebrospinal fluid. In the present study, ICV injection of IL-1 or E. coli endotoxin (a stimulus for the synthesis of IL-1), significantly elevated body temperature, but did not affect food intake of fasted rats. We conclude that receptors mediating the anorexigenic actions of IL-1 or endotoxin are not located at a central nervous site bathed by the cerebrospinal fluid. Furthermore, fever per se is not reponsible for the reduction in food intake seen following peripheral injection of IL-1 or endotoxin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26437/1/0000525.pd