Effects of opioid peptides on thermoregulation
In a given species, injected opioid peptides usually cause changes in temperature similar to those caused by nonpeptide opioids. The main effect in those species most studied, the cat, rat, and mouse, is an increase in the level about which body temperature is regulated; there is a coordinated change in the activity of thermoregulatory effectors such that hyperthermia is produced in both hot and cold environments. Larger doses may depress thermoregulation, thereby causing body temperature to decrease in the cold. Elicitation of different patterns of response over a range of environmental temperatures and studies with naloxone and naltrexone indicate that stimulation of a number of different receptors by both peptide and nonpeptide opioids can evoke thermoregulatory responses. ..beta..-Endorphin is readily antagonized by naloxone whereas methionine-enkephalin can act on naloxone-insensitive receptors. Moreover, synthetic peptide analogs do not necessarily evoke the same response as does the related endogenous peptide. The lack of effect of naloxone on body temperature of subjects housed at usual laboratory temperature or on pyrogen-induced increases in body temperature indicates that an action of endogenous peptides on naloxone-sensitive receptors plays little, if any, role in normal thermoregulation or in fever. However, there is some evidence that such an action may be involved in responses to restraint or ambient temperature-induced stress. Further evaluation of possible physiological roles of endogenous opioid peptides will be facilitated when specific antagonists at other types of opioid receptors become available.
- Research Organization:
- Univ. of Texas Health Science Center, Dallas
- OSTI ID:
- 5725527
- Journal Information:
- Fed. Proc.; (United States), Journal Name: Fed. Proc.; (United States) Vol. 40:3; ISSN FEPRA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
560205* -- Thermal Effects-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOLOGICAL PATHWAYS
CONTROL
DOCUMENT TYPES
DRUGS
ENDORPHINS
ENKEPHALINS
NEUROREGULATORS
ORGANIC COMPOUNDS
PEPTIDES
POLYPEPTIDES
PROTEINS
REVIEWS
TEMPERATURE CONTROL
THERMOREGULATION