Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0278080 (physical dependence)
 1,658 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of chronic administration of morphine and subsequent withdrawal on brain and pituitary receptors for thyrotropin releasing hormone (TRH) was investigated in Sprague-Dawley rats. The rats were implanted subcutaneously with four morphine pellets (each containing 75 mg of morphine free base) during a 3-day period. Placebo pellets, which contained all the excipients of morphine pellets except the morphine, were implanted in rats which served as controls. Both tolerance and physical dependence on morphine have been shown to develop as a result of this procedure. TRH receptors were labeled with 3H-(3-MeHis2) TRH (MeTRH). 3H-MeTRH bound to brain membranes at a single high affinity site with Bmax (receptor density) value of 24.6 +/- 2.2 fmol/mg protein and Kd (apparent dissociation constant) value of 3.7 +/- 0.4 nM. The binding of 3H-MeTRH to five regions of the brain namely, hypothalamus, cortex, striatum, midbrain and pons + medulla, as well as pituitary was also investigated. The binding of 3H-MeTRH to pituitary membranes was increased during the development of tolerance, whereas the binding to membranes prepared from different brain regions was unaffected. Serum concentration of triiodothyronine (T3) and thyroxine (T4) were found to be lower in chronic morphine-treated rats when compared to placebo-treated rats, however, serum TSH level remained unaltered. Twenty-four hours after the removal of morphine pellets (natural withdrawal), the binding of 3H-MeTRH to pons + medulla membranes was greater than in placebo control group. Naloxone-precipitated withdrawal produced results which were qualitatively similar to those obtained in rats from which pellets had been removed. The results suggest that the development of tolerance to morphine may be associated with changes in the pituitary-thyroid axis.
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PMID:The binding of 3H-(3-MeHis2) thyrotropin releasing hormone to brain and pituitary membranes of morphine tolerant-dependent and abstinent rats. 251 32

It has been shown that alcohol-motivated Wistar female rats after 10 days of repeated ethanol administration have a decreased cold- or TRH-stimulated TSH level in the blood serum under physical dependence and abstinence. There were no changes of TSH secretion in animals non-motivated to alcohol. Acetaldehyde inhibited significantly the TSH cold-response but did not influence the TRH-induced TSH secretion. It is suggested that repeated ethanol administration causes hypofunction of both hypothalamic TRH neurons and anterior pituitary thyrotropic cells. Partially it may depend on acetaldehyde inhibitory action on the hypothalamic level of regulation of thyroid gland functioning.
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PMID:[Effect of alcohol on serum thyrotropin concentration of rats predisposed and unpredisposed to alcohol]. 719 60