Skip to main content
Log in

Purification of endogenous inhibitors of [3H]flunitrazepam binding from bovine brain

  • Original Articles
  • Published:
Neurochemical Research Aims and scope Submit manuscript

Abstract

Endogenous substances which inhibited the binding of [3H]flunitrazepam ([3H]FNZ) to bovine synaptosomal membranes have been purified from the hot acetic acid extracts of the bovine brain. Three peaks of inhibitory activity were obtained by Sephadex G-10 gel chromatography. Two of the peaks (Peak 2, and Peak 3) which had lower molecular weights that that of peak 1 were identified as inosine and hypoxanthine by TLC methods. Another peak (Peak 1) was further purified to homogeneity using both cation and anion ion-exchange chromatography and the following two-step reversed-phase HPLC. The purified substance inhibited the [3H]FNZ binding dose-dependently and competitively but did not have an effect on the binding of the peripheral-type BZ ligand [3H]Ro 5-4864. It was also shown that the substance was heat-stable and resistant to proteolytic degradation (trypsin, α-chymotrypsin, pronase). However, a significant loss of inhibitory activity to [3H]FNZ binding was observed after acid hydrolysis. Molecular weight estimates based on gel filtration methods were less than 500 dalton, and the maximal ultraviolet absorption peak was at 314 nm. These results suggest that this substance is a new endogenous ligand for the central BZ receptor and may play an important role in regulating the GABAergic tone in the central nervous system.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Haefly, W. 1984. Benzodiazepine interactions with GABA receptors. Neurosci. Lett. 47:201–206.

    Google Scholar 

  2. Mohler, H., and Okada, T. 1977. Benzodiazepine receptor: demonstration in the central nervous system. Science. 198:849–851.

    Google Scholar 

  3. Squires, R. F., and Braestrup, C. 1977. Benzodiazepine receptors in rat brain. Nature. 266:732–734.

    Google Scholar 

  4. Olsen, R., and Vender, C., (eds.), 1986. Benzodiazepine/GABA receptors and chloride channels: structural and functional properties. Alan Liss, Inc., New York.

    Google Scholar 

  5. Tallman, J. F., Thomas, J. W., and Gallager, D. W. 1978. BABAergic modulation in benzodiazepine binding site sensitivity. Nature. 274:383–385.

    Google Scholar 

  6. Möhler, H., and Okada, T., Heitz, P. H., and Ulrich, J. 1978. Biochemical identification of the site of action on benzodiazepines in human brain by3H-diazepam binding. Life Sci. 22:985–996.

    Google Scholar 

  7. Tallman, J. F., Paul, S., Skolnick, P., and Gallager, D. W. 1980. Receptors for the age of anxiety: pharmacology of benzodiazepines. Science. 207:274–281.

    Google Scholar 

  8. Tallman, J. F., and Gallager, D. W. 1985. The GABAergic system: a locus of benzodiazepine action. Annu. Rev. Neurosci. 8:21–44.

    Google Scholar 

  9. Marangos, P. J., Paul, S. M., Goodwin, F. K., and Skolnick, P. 1979. Putative endogenous ligands for the benzodiazepine receptor. Life Sci. 25:1093–1102.

    Google Scholar 

  10. Hamon, M., and Soubrie, P. 1983. Searching for endogenous ligand(s) of central benzodiazepine receptors. Neurochem. Inter. 5:663–672.

    Google Scholar 

  11. Stephenson, F. A. 1987. Benzodiazepines in the brain. Trends Neurosci. 10:185–186.

    Google Scholar 

  12. Skolnick, P., Marangos, P. J., Goodwin, F. K., Edwards, M., and Paul, S. 1978. Identification of inosine and hypoxanthine as endogenous inhibitors of [3H]diazepam binding in the central nervous system. Life Sci. 23:1473–1480.

    Google Scholar 

  13. Asano T., and Spector S. 1979. Identification of inosine and hypoxanthine as endogenous ligands for the brain benzodiazepine binding sites. Proc. Natl. Acad. Sci. USA. 76:977–981.

    Google Scholar 

  14. Marangos P. J., Clark R., Martino A. M., Paul S. M., and Skolnick P. 1979. Demonstration two new endogenous “benzodiazepine-like” compounds from brain. Psychiat. Res. 1:121–130.

    Google Scholar 

  15. Mohler H., Polc P., Cumin R., Pieri L., and Kettler R. 1979. Nicotinamide is a brain constituent with benzodiazepine-like actions. Nature. 278:563–565.

    Google Scholar 

  16. Pena C., Medina J. H., Novas M. L., Paladini A. C., and Robertis E. D. 1986. Isolation and identification in bovine cerebral cortex of n-butyl-β-carboline-3-carboxylate, a potent benzodiazepine binding inhibitor. Proc. Natl. Acad. Sci. USA. 83:4952–4956.

    Google Scholar 

  17. Braestrup C., Nielsen M., and Olsen C. E. 1980. Urinary and brain β-carbolin-3-carboxylates as potent inhibitors of brain benzodiazepine recepters. Proc. Natl. Acad. Sci. USA. 77:2288–2292.

    Google Scholar 

  18. Rommelspacher H., Nanz C., Borbe H. O., Fehske K. J., Muller W. E., and Wollert U. 1981. Benzodiazepine antagonism by harmane and other β-carbolines in vitro and in vivo. Eur. J. Pharmac. 70:409–416.

    Google Scholar 

  19. Asano T., and Ogasawara N. 1982. Prostaglandins A as possible endogenous ligands of benzodiazepine receptor. Eur. J. Pharmac. 80:271–274.

    Google Scholar 

  20. Ally A. I., Manku M. S., Howobin D. F., Karmali R. A., Morgan R. O., and Karmazyn M. 1978. Thromboxane A2 as a possible natural ligand for benzodiazepine receptors. Neurosci. Lett. 7:31–34.

    Google Scholar 

  21. Nagy A., and Lajtha A. 1983. Thyroid hormones and derivatives inhibit flunitrazepam binding. J. Neurochem. 40:414–417.

    Google Scholar 

  22. Marangos P. J., Patel J., Hirata F., Sondheim D., Paul S. M., Skolnick P., and Goodwin F. K. 1981. Inhibition of diazepam binding by tryptophan derivatives including melatonin and its brain metabolite N-acetyl-5-methoxy-kynuramine. Life Sci. 29:259–267.

    Google Scholar 

  23. Elsworth J. D., Dewar D., Glover V., Goodwin B. L., Clow A., and Sandler M. 1986. Purification and characterization of tribulin, an endogenous inhibitor of monoamine oxidase and of benzodiazepine receptor binding. J. Neural Transm. 67:45–56.

    Google Scholar 

  24. Glover V., Halket J. M., Watkins P. J., Clow A., Goodwin B. L., and Sandler M. 1988. Isatin: Identity with the purified endogenous monoamine oxidase inhibitor Tribulin. J. Neurochem. 51:656–659.

    Google Scholar 

  25. Sangameswaran L., Fales H. M.. Friedrich P., and Blas A. L. D. 1986. Purification of a benzodiazepine from bovine brain and detection of benzodiazepine-like immunoreactivity in human brain. Proc. Natl. Acad. Sci. USA. 83:9236–9240.

    Google Scholar 

  26. Wildmann J., Niemann J., and Matthaei H. 1986. Endogenous benzodiazepine receptor agonist in human and mammalian plasma. J. Neural Transm. 66:151–160.

    Google Scholar 

  27. Wildmann J., Mohler H., Vetter W., Ranalder U., Schmidt K., and Maurer R. 1987. Diazepam and N-desmethyldiazepam are found in rat brain and adrenal and may be of plant origin. J. Neural Transm. 70:383–398.

    Google Scholar 

  28. Basile A. S., Gammal S. H., Jones E. A., and Skolnick P. 1989. GABAA receptor complex in an experimental model of hepatic encephalopathy:evidence for elevated levels of an endogenous benzodiazepine receptor ligand. J. Neurochem. 53:1057–1063.

    Google Scholar 

  29. Wu J. Y., Lin H. S., Lin C. T., Wei S. C., Liu J. W., and Xu Y. 1986. Isolation, purification, and immunochemical studies of benzodiazepine receptor(s) and its ligand(s) for mammaliam brain. Pages 161–176, in: Biggio G, and Costa E. (eds.), GABAergic transmission and anxiety. New York: Raven Press.

    Google Scholar 

  30. Liao C. C., Lin H. S., Liu J.-Y., Hibbard L. S., and Wu J-Y. 1989. Purification and characterization of a benzodiazepine-like substance from mammalian brain. Neurochem. Res. 14:345–352.

    Google Scholar 

  31. Guidotti A., Forchetti C. M., Corda M. G., Konkel D., Bennett C. D., and Costa E. 1983. Isolation, characterization, and purification to homogeneity of an endogenous polypeptide with agonistic action on benzodiazepine receptor. Proc. Natl. Acad. Sci. USA. 80:3531–3535.

    Google Scholar 

  32. Fererro P., Santi M. R., Conti-Tronconi B., Costa E., and Guidotti A. 1986. Study of an octadecaneuropeptide derived from diazepam binding inhibitor (DBI): Biological activity and presence in rat brain. Proc. Natl. Acad. Sci. USA. 83:827–831.

    Google Scholar 

  33. Shoyab M., Gentry L. E., Marquardt H., and Todaro G. J. 1986. Isolation and characterization of a putative endogenous benzodiazepinoid (endozepine) from bovine and human brain. J. Biol. Chem. 261:11968–11973.

    Google Scholar 

  34. Collelo G. D., Hockenbery D. M., Bosmann H. B., Fuchs S., and Folkers K. 1978. Competitive inhibition of benzodiazepine binding by fractions from porcine brain. Proc. Natl. Acad. Sci. USA. 75:6319–6323.

    Google Scholar 

  35. Deckert J., Kuhn W., and Przuntek H. 1984. Endogenous benzodiazepine ligands in human cerebrospinal fluid. Peptides, 5:641–644.

    Google Scholar 

  36. Fanelli R., and McNamara J. O. 1986. Effects of age on kindling and kindled seizure-induced increase of benzodiazepine receptor binding. Brain Res. 362:17–22.

    Google Scholar 

  37. Daval J- L., Post R. M., and Marangos P. J. 1989. Pyruvate dehydrogenase interactions with peripheral-type benzodiazepine receptors. J. Neurochem. 52:110–116.

    Google Scholar 

  38. Lowry O. H., Rosebrough N. J., Farr A. L., and Randall R. J. 1951. Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193:265–275.

    Google Scholar 

  39. Uphaus R. A., Grossweiner L. I., Katz J. J., and Kopple K. D. 1959. Fluorescence of Tryptophan Derivatives in Trifluoroacetic Acid. Science, 129:641–643.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kawasaki, H., Itoh, M., Nakahara, T. et al. Purification of endogenous inhibitors of [3H]flunitrazepam binding from bovine brain. Neurochem Res 16, 1227–1233 (1991). https://doi.org/10.1007/BF00966700

Download citation

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00966700

Key Words

Navigation