, Volume 49, Issue 1, pp 57–62 | Cite as

Influence of thyrotropin releasing hormone (TRH) on drug-induced narcosis and hypothermia in rabbits

  • A. Horita
  • M. A. Carino
  • R. M. Chesnut
Animal Studies


Thyrotropin releasing homone (TRH) administered via the intracerebroventricular (icv) route in doses ranging between 0.1 and 100 μg decreased the duration of pentobarbital-induced narcosis in rabbits. Antagonism of narcosis occurred whether TRH was administered before or after the barbiturate. TRH doses above 10 μg produced, in addition, behavioral excitation and hyperthermia. The antagonism of phenobarbital-induced narcosis was not as profound; animals were aroused only for a short period of time, after which the narcotized state returned. However, TRH exerted a prolonged antagonism or reversal of the phenobarbital-induced hypothermia. The central nervous system depression and analgesia produced by morphine were unaffected by TRH, but hypothermia and respiratory depression were reversed. TRH may represent an arousal factor in mammalian brain.

Key words

Arousal TRH Barbiturates Morphine Hyperthermia 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Birk, J., Rothenbuchner, G., Loos, U., Raptis, S., Fletcher, S., Pfeiffer, E. F.: The preparation of 125I-TRH: Its distribution, half-life and excretion in mice. In: Hypothalamic hypophysiotropic hormones, C. Gual and E. Rosenberg, eds., pp. 141–145. Amsterdam: Excerpta Medica 1973Google Scholar
  2. Breese, G. R., Cott, J. M., Cooper, B. R., Prange, A. J., Lipton, M. A., Plotnikoff, N. P.: Effects of thyrotropin-releasing hormone (TRH) on the actions of pentobarbital and other centrally acting drugs. J. Pharmacol. exp. Ther. 193, 11–22 (1975)Google Scholar
  3. Brown, M., Vale, W.: Central nervous system effects of hypothalamic peptides. Endocrinology 96, 1333–1336 (1975)Google Scholar
  4. Burt, D. R., Snyder, S. H.: Thyrotropin releasing hormone (TRH): Apparent receptor binding in rat brain membranes. Brain Res. 93, 309–328 (1975)Google Scholar
  5. Hill, H. F., Horita, A.: Inhibition of (+)-amphetamine hyperthermia by blockade of dopamine receptors in rabbits. J. Pharm. Pharmacol. 23, 715–717 (1971)Google Scholar
  6. Horita, A., Carino, M. A.: Thyrotropin-releasing hormone (TRH)-induced hyperthermia and behavioral excitation in rabbits. Psychopharmacol. Commun. 1, 403–414 (1975)Google Scholar
  7. Horita, A., Carino, M. A.: Effect of PCPA and methergoline on the pentobarbital-TRH interaction in rabbits. Fed. Proc. (in press, 1976)Google Scholar
  8. Horita, A., Carino, M. A., Weick, B. G.: Effects of thyrotropin releasing hormone (TRH) microinjected into various areas of conscious and pentobarbital-pretreated rabbits. Proc. West. Pharmacol. Sco. (in press, 1976)Google Scholar
  9. Jacob, J., Girault, J. M., Peindaries, R.: Actions of 5-hydroxytryptamine and 5-hydroxytryptophan injected by various routes on the rectal temperature of the rabbit. Neuropharmacology 11, 1–16 (1972)Google Scholar
  10. Kastin, A. J., Ehrensing, R. H., Schalch, D. S., Anderson, M. S.: Improvement in mental depression with decreased thyrotropin response after administration of thyrotropin-releasing hormone. Lancet 1972II, 740–742Google Scholar
  11. Krivoy, W., Zimmermann, E.: A possible role of polypeptides in synaptic transmission. In: Chemical modulation of brain function, H. C. Sabelli, ed., pp. 111–121. New York: Raven Press 1973Google Scholar
  12. Plotnikoff, N. P., Prange, A. J., Jr., Breese, G. R., Anderson, M. S., Wilson, I. C.: Thyrotropin releasing hormone: Enhancement of dopa activity by a hypothalamic hormone. Science 178, 417–418 (1972)Google Scholar
  13. Plotnikoff, N. P., Prange, A. J., Jr., Breese, G. R., Anderson, M. S., Wilson, I. C.: The effects of thyrotropin-releasing hormone on DOPA response in normal, hypophysectomized, and thyroidectomized animals. In: The thyroid axis, drugs, and behavior, A. J. Prange, ed., pp. 103–113. New York: Raven Press 1974Google Scholar
  14. Prange, A. J., Jr., Breese, G. R., Cott, J. M., Martin, B. R., Cooper, B. R., Wilson, I. C., Plotnikoff, N. P.: Thyrotropin releasing hormone: Antagonism of pentobarbital in rodents. Life Sci. 14, 447–455 (1974)Google Scholar
  15. Prange, A. J., Jr., Wilson, I. C., Lara, P. P., Alltop, L. B., Breese, G. R.: Effects of thyrotropin-releasing hormone in depression. Lancet 1972II, 999–1007Google Scholar
  16. Winokur, A., Utiger, R. D.: Thyrotropin-releasing hormone: Regional distribution in rat brain. Science 185, 265–267 (1974)Google Scholar

Copyright information

© Springer-Verlag 1976

Authors and Affiliations

  • A. Horita
    • 1
  • M. A. Carino
    • 1
  • R. M. Chesnut
    • 1
  1. 1.Department of Pharmacology, School of MedicineUniversity of WashingtonSeattleUSA

Personalised recommendations