The set point may also be affected by substances
including prostaglandin E2 (PGE2), lipopolysaccharides
from bacterial cell walls, proteins, protein breakdown
products and/or endotoxins from injured or
degenerating tissues and phagocytosed bacteria.
Interleukin-1 (IL-1) may be released by white blood
cells, which reaches the hypothalamus and causes an
increase in temperature. IL-6, IL-10, interferon and
tumour necrosis factor have also been shown to cause
fever, by increasing the production of PGE2 (Sieck,
2002; Biddle, 2006).