Pyrogens enhance beta-endorphin release in hypothalamus and trigger fever that can be attenuated by buprenorphine.

Abstract

At first, we investigated whether both beta-endorphin release level in the hypothalamus and body temperature can be altered after intracerebroventricular (i.c.v.) injection of either lipopolysaccharide (LPS), interleukin-1beta (IL-1beta), or prostaglandin E(2) (PGE(2)) in rats. It was found that in the rat, i.c.v. administration of either LPS (0.5 microg in 10 microl), IL-1beta (10 ng in 10 microl), or PGE(2) (200 ng in 10 microl), in addition to producing fever, upregulated the immunoreactivity of beta-endorphin in the preoptic anterior hypothalamus of rat brain. Secondarily, we assessed whether the fever induced by either LPS, IL-1beta, or PGE(2) can be altered by pretreatment with buprenorphine (an opioid receptor antagonist). The results revealed that i.c.v. administration of buprenorphine (1 - 10 microg in 10 microl) alone had an insignificant effect on the body temperature. However, the fever induced by i.c.v. injection of either LPS, IL-1beta, or PGE(2) was significantly attenuated by pretreatment with i.c.v. injection of buprenorphine 1 h before the pyrogen injection in rats. The results suggest that pyrogens enhance beta-endorphin release in the hypothalamus and trigger fever which can be attenuated by buprenorphine, an opioid receptor antagonist.

• Authors: Shu-Ming Tsai, Mao-Tsun Lin, Jhi-Joung Wang, Wu-Tein Huang
• Journal: Journal of pharmacological sciences (J Pharmacol Sci) Vol. 93 Issue 2 Pg. 155-62 (Oct 2003) ISSN: 1347-8613 [Print] Japan
• PMID: 14578583 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Interleukin-1
• Lipopolysaccharides
• Narcotic Antagonists
• Pyrogens
• Buprenorphine
• beta-Endorphin
• Dinoprostone

Topics

• Animals
• Buprenorphine (administration & dosage, pharmacology)
• Dinoprostone (administration & dosage, pharmacology)
• Fever (chemically induced, prevention & control)
• Hypothalamus (drug effects, metabolism)
• Immunohistochemistry
• Injections, Intraventricular
• Interleukin-1 (administration & dosage, pharmacology)
• Lipopolysaccharides (administration & dosage, pharmacology)
• Male
• Narcotic Antagonists (administration & dosage, pharmacology)
• Pyrogens (administration & dosage, antagonists & inhibitors, pharmacology)
• Rats
• Rats, Sprague-Dawley
• beta-Endorphin (metabolism)