cap alpha. -Methyl-p-tyrosine shifts circadian temperature rhythms

Journal Article · Wed Sep 01 00:00:00 EDT 1982 · Am. J. Physiol.; (United States)

OSTI ID:6324259

Cahill, A L; Ehret, C F

..cap alpha..-Methyl-p-tyrosine shifts the acrophase (time of highest temperature) of the circadian temperature rhythm of the rat to earlier or later times of day depending on the phase of the cicadian cycle at which the drug is administered. When ..cap alpha..-methyl-p-tyrosine methyl ester HCl is injected intraperitoneally at a dose of 100 mg/kg late in the projected 8-h light phase, the acrophase of the intraperitoneal temperature rhythm is delayed by up to 3 h.However, when the same dose of drug is given 9-10 h into the projected 16-h dark phase of the daily cycle, the acrophase of the temperature rhythm occurs about 2 h earlier than expected. The times of ..cap alpha..-methyl-p-tyrosine administration leading to maximal phase delays or advances are correlated with the times of minimal and maximal turnover of norepinephrine in the hypothalamus. These results suggest that changing rates of norepinephrine turnover in the hypothalamus may regulate the circadian temperature rhythm in rats. The results also emphasize the fact that the effects of drugs may vary as a function of the time of administration. This fact must be taken into account in pharmacologic testing.

• Research Organization: Argonne National Lab., IL
• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 6324259
• Journal Information: Am. J. Physiol.; (United States), Vol. 243:3
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
BIOLOGICAL EFFECTS
HYPOTHALAMUS
BIOLOGICAL FUNCTIONS
THERMOREGULATION
DAILY VARIATIONS
INTRAPERITONEAL INJECTION
NORADRENALINE
RATS
ADRENAL HORMONES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
BRAIN
CARBOXYLIC ACIDS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CENTRAL NERVOUS SYSTEM
CONTROL
DRUGS
FUNCTIONS
HORMONES
INJECTION
INTAKE
MAMMALS
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RODENTS
STEROID HORMONES
SYMPATHOMIMETICS
TEMPERATURE CONTROL
VARIATIONS
VERTEBRATES
560205* - Thermal Effects- Vertebrates- (-1987)
551000 - Physiological Systems