Spinal cord thyrotropin releasing hormone receptors of morphine tolerant-dependent and abstinent rats

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Peptides (Fayetteville, New York); (USA)

DOI:https://doi.org/10.1016/0196-9781(90)90182-5· OSTI ID:6324786

Rahmani, N H; Gulati, A; Bhargava, H N ^[1]

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1. Univ. of Illinois, Chicago (USA)

The effect of chronic administration of morphine and its withdrawal on the binding of 3H-(3-MeHis2)thyrotropin releasing hormone (3H-MeTRH) to membranes of the spinal cord of the rat was determined. Male Sprague-Dawley rats were implanted with either 6 placebo or 6 morphine pellets (each containing 75-mg morphine base) during a 7-day period. Two sets of animals were used. In one, the pellets were left intact at the time of sacrificing (tolerant-dependent) and in the other, the pellets were removed 16 hours prior to sacrificing (abstinent rats). In placebo-pellet-implanted rats, 3H-MeTRH bound to the spinal cord membranes at a single high affinity binding site with a Bmax of 21.3 +/- 1.6 fmol/mg protein, and an apparent dissociation constant Kd of 4.7 +/- 0.8 nM. In morphine tolerant-dependent or abstinent rats, the binding constants of 3H-MeTRH to spinal cord membranes were unaffected. Previous studies from this laboratory indicate that TRH can inhibit morphine tolerance-dependence and abstinence processes without modifying brain TRH receptors. Together with the present results, it appears that the inhibitory effect of TRH on morphine tolerance-dependence and abstinence is probably not mediated via central TRH receptors but may be due to its interaction with other neurotransmitter systems.

• OSTI ID: 6324786
• Journal Information: Peptides (Fayetteville, New York); (USA), Journal Name: Peptides (Fayetteville, New York); (USA) Vol. 11:4; ISSN 0196-9781; ISSN PPTDD
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALOIDS
ANALGESICS
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DRUGS
HORMONES
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
MORPHINE
NARCOTICS
NERVOUS SYSTEM
OPIUM
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SPINAL CORD
TRACER TECHNIQUES
TRH
TRITIUM COMPOUNDS
VERTEBRATES