Abstract
The behavioral effects of β-endorphin, [D-Ala2, D-Leu5]-enkephalin and morphine were investigated in golden hamsters and in rats. In golden hamsters, β-endorphin and [D-Ala2, D-Leu5]-enkephalin induced loss of righting reflex, whereas morphine caused no such effect. Both opiate peptides and morphine caused the inhibition of tail-flick response and catalepsy in rats. β-Endorphin was the most potent, followed by [D-Ala2, D-Leu5]-enkephalin and then by morphine. The catalepsy induced in rats by [D-Ala2, D-Leu5]-enkephalin was different from that of β-endorphin and morphine in that it produced catalepsy without muscular rigidity. β-Endorphin and [D-Ala2, D-Leu5]-enkephalin caused hypothermia in golden hamsters; morphine was less active in altering the body temperature. β-Endorphin caused hypothermia at high doses and hyperthermia at low doses in rats. These heterogenous behavioral responses indicate that multiple types of receptors mediate the effects of opiates in the central nervous system.
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References
Bloom, F., Segal, D., Ling, M., Guillemin, R.: Endorphins: profound behavioral effects in rats suggest new etiological factors in mental illness. Science 194, 630–632 (1976)
Gilbert, P. E., Martin, W. R.: The effects of morphine and nalorphine like drugs in the nondependent, morphine-dependent and cyclazocine-dependent chronic spinal dog. J. Pharmacol. Exp. Ther. 198, 66–82 (1976)
Holaday, J. W., Law, P-Y, Tseng, L-F., Loh, H. H., Li, C. H.: β-Endorphin: pituitary and adrenal glands modulate its action. Proc. Natl. Acad. Sci. USA 74, 4628–4632 (1977)
Jacquet, Y. F., Marks, N.: The C-fragment of β-lipotropin: an endogenous neuroleptic or antipsychotogen? Science 194, 632–634 (1976)
Li, C. H., Chung, D.: Isolation and structure of an untriacontapeptide with opiate activity from camel pituitary glands. Proc. Natl. Acad. Sci. USA 73, 1145–1148 (1976)
Li, C. H., Yamashiro, D., Tseng, L.-F., Loh, H. H.: Synthesis and analgesic activity of human β-endorphin. J. Med. Chem. 20, 325–328 (1977)
Litchfield, J. T., Wilcoxon, F. A.: Simplified method of evaluating dose-effect experiments. J. Pharmacol. Exp. Ther. 96, 99–113 (1949)
Martin, W. R.: Opioid antagonists. Pharmacol. Rev. 19, 463–521 (1967)
Martin, W. R., Eades, C. G., Thompson, J. A., Huppler, R. E., Gilbert, P. E.: The effects of morphine and nalorphinelike drugs in the nondependent and morphine-dependent chronic spinal dog. J. Pharmacol. Exp. Ther. 197, 517–532 (1977)
Tseng, L.-F., Loh, H. H., Li, C. H.: Human β-endorphin: development of tolerance and behavioral activity in rats. Biochem. Biophys. Res. Commun. 74, 390–396 (1977)
Wei, E. T., Tseng, L.-F., Loh, H. H., Li, C. H.: Comparison of the behavioral effects of β-endorphin and enkephalin analogs. Life Sci. 21, 321–328 (1977)
Winter, C. A., Flataker, L.: Studies on hepatazone (6-morpholine-4,4-diphenyl-3-heptanone hydrochloride) in comparison with other analgesic drugs. J. Pharmacol. Exp. Ther. 98, 305–317 (1950)
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Tseng, LF., Ostwald, T.J., Loh, H.H. et al. Behavioral activities of opioid peptides and morphine sulfate in golden hamsters and rats. Psychopharmacology 64, 215–218 (1979). https://doi.org/10.1007/BF00496065
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DOI: https://doi.org/10.1007/BF00496065