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. 1995 Oct;116(3):2076–2080. doi: 10.1111/j.1476-5381.1995.tb16414.x

New high affinity peptide antagonists to the spinal galanin receptor.

X J Xu 1, Z Wiesenfeld-Hallin 1, U Langel 1, K Bedecs 1, T Bartfai 1
PMCID: PMC1908937  PMID: 8640348

Abstract

1. The role of endogenous galanin in somatosensory processing has been studied with galanin receptor antagonists. The new galanin receptor ligands C7, M32, M38 and M40 bind with high affinity (Kd in nanomolar range) to spinal cord galanin receptors and possess oxidative stability as compared to earlier generations of peptide ligands. These peptides have been examined in the spinal flexor reflex model where exogenous galanin exhibited biphasic excitatory and inhibitory effects. 2. Intrathecal administration of C7 [galanin(1-13)-spantide] and M32 [galanin (1-13)-neuropeptide Y(25-36) amide] blocked facilitation of the nociceptive flexor reflex induced by 30 pmol intrathecal galanin in decerebrate, spinalized rats in a dose-dependent manner, thus behaving as antagonists of the galanin receptor. In contrast, M38[galanin(1-13)-(Ala-Leu)3-Ala amide] and M40 [galanin(1-13)-Pro-Pro-(Ala-Leu)2-Ala amide], exhibited only weak antagonism at high doses in this model. Moreover, lower doses of M40 potentiated galanin-induced reflex facilitation. C7 was neurotoxic at high doses in the rat spinal cord. 3. M32 and C7 were potent antagonists of galanin receptors in rat spinal cord, in correlation with their in vitro binding characteristics. In contrast, M38 and M40, despite their high in vitro affinity, exhibited only very weak antagonism. Moreover, M40 may also behave as a partial agonist. 4. Previous studies have shown that the galanin receptor may be heterogeneous. The discrepancy between in vitro binding and in vivo antagonistic potency of M38 and M40 may also suggest the presence of different galanin receptor subtypes within the rat spinal cord. However, other explanations for the discrepancy, such as differences in metabolic stability, diffusion rates and penetration to the site of action are also possible.

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Selected References

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  1. Bartfai T., Bedecs K., Land T., Langel U., Bertorelli R., Girotti P., Consolo S., Xu X. J., Wiesenfeld-Hallin Z., Nilsson S. M-15: high-affinity chimeric peptide that blocks the neuronal actions of galanin in the hippocampus, locus coeruleus, and spinal cord. Proc Natl Acad Sci U S A. 1991 Dec 1;88(23):10961–10965. doi: 10.1073/pnas.88.23.10961. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bartfai T., Fisone G., Langel U. Galanin and galanin antagonists: molecular and biochemical perspectives. Trends Pharmacol Sci. 1992 Aug;13(8):312–317. doi: 10.1016/0165-6147(92)90098-q. [DOI] [PubMed] [Google Scholar]
  3. Bartfai T., Hökfelt T., Langel U. Galanin--a neuroendocrine peptide. Crit Rev Neurobiol. 1993;7(3-4):229–274. [PubMed] [Google Scholar]
  4. Bartfai T., Langel U., Bedecs K., Andell S., Land T., Gregersen S., Ahrén B., Girotti P., Consolo S., Corwin R. Galanin-receptor ligand M40 peptide distinguishes between putative galanin-receptor subtypes. Proc Natl Acad Sci U S A. 1993 Dec 1;90(23):11287–11291. doi: 10.1073/pnas.90.23.11287. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bedecs K., Langel U., Bartfai T., Wiesenfeld-Hallin Z. Galanin receptors and their second messengers in the lumbar dorsal spinal cord. Acta Physiol Scand. 1992 Mar;144(3):213–220. doi: 10.1111/j.1748-1716.1992.tb09289.x. [DOI] [PubMed] [Google Scholar]
  6. Ch'ng J. L., Christofides N. D., Anand P., Gibson S. J., Allen Y. S., Su H. C., Tatemoto K., Morrison J. F., Polak J. M., Bloom S. R. Distribution of galanin immunoreactivity in the central nervous system and the responses of galanin-containing neuronal pathways to injury. Neuroscience. 1985 Oct;16(2):343–354. doi: 10.1016/0306-4522(85)90007-7. [DOI] [PubMed] [Google Scholar]
  7. Cheng Y., Prusoff W. H. Relationship between the inhibition constant (K1) and the concentration of inhibitor which causes 50 per cent inhibition (I50) of an enzymatic reaction. Biochem Pharmacol. 1973 Dec 1;22(23):3099–3108. doi: 10.1016/0006-2952(73)90196-2. [DOI] [PubMed] [Google Scholar]
  8. Crawley J. N., Austin M. C., Fiske S. M., Martin B., Consolo S., Berthold M., Langel U., Fisone G., Bartfai T. Activity of centrally administered galanin fragments on stimulation of feeding behavior and on galanin receptor binding in the rat hypothalamus. J Neurosci. 1990 Nov;10(11):3695–3700. doi: 10.1523/JNEUROSCI.10-11-03695.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Crawley J. N., Robinson J. K., Langel U., Bartfai T. Galanin receptor antagonists M40 and C7 block galanin-induced feeding. Brain Res. 1993 Jan 15;600(2):268–272. doi: 10.1016/0006-8993(93)91382-3. [DOI] [PubMed] [Google Scholar]
  10. Fisone G., Berthold M., Bedecs K., Undén A., Bartfai T., Bertorelli R., Consolo S., Crawley J., Martin B., Nilsson S. N-terminal galanin-(1-16) fragment is an agonist at the hippocampal galanin receptor. Proc Natl Acad Sci U S A. 1989 Dec;86(23):9588–9591. doi: 10.1073/pnas.86.23.9588. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Habert-Ortoli E., Amiranoff B., Loquet I., Laburthe M., Mayaux J. F. Molecular cloning of a functional human galanin receptor. Proc Natl Acad Sci U S A. 1994 Oct 11;91(21):9780–9783. doi: 10.1073/pnas.91.21.9780. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hua X. Y., Boublik J. H., Spicer M. A., Rivier J. E., Brown M. R., Yaksh T. L. The antinociceptive effects of spinally administered neuropeptide Y in the rat: systematic studies on structure-activity relationship. J Pharmacol Exp Ther. 1991 Jul 1;258(1):243–248. [PubMed] [Google Scholar]
  13. Kar S., Quirion R. Quantitative autoradiographic localization of [125I]neuropeptide Y receptor binding sites in rat spinal cord and the effects of neonatal capsaicin, dorsal rhizotomy and peripheral axotomy. Brain Res. 1992 Mar 6;574(1-2):333–337. doi: 10.1016/0006-8993(92)90836-x. [DOI] [PubMed] [Google Scholar]
  14. Langel U., Land T., Bartfai T. Design of chimeric peptide ligands to galanin receptors and substance P receptors. Int J Pept Protein Res. 1992 Jun;39(6):516–522. doi: 10.1111/j.1399-3011.1992.tb00282.x. [DOI] [PubMed] [Google Scholar]
  15. Melander T., Hökfelt T., Rökaeus A. Distribution of galaninlike immunoreactivity in the rat central nervous system. J Comp Neurol. 1986 Jun 22;248(4):475–517. doi: 10.1002/cne.902480404. [DOI] [PubMed] [Google Scholar]
  16. Post C., Paulsson I. Antinociceptive and neurotoxic actions of substance P analogues in the rat's spinal cord after intrathecal administration. Neurosci Lett. 1985 Jun 12;57(2):159–164. doi: 10.1016/0304-3940(85)90056-4. [DOI] [PubMed] [Google Scholar]
  17. Rossowski W. J., Rossowski T. M., Zacharia S., Ertan A., Coy D. H. Galanin binding sites in rat gastric and jejunal smooth muscle membrane preparations. Peptides. 1990 Mar-Apr;11(2):333–338. doi: 10.1016/0196-9781(90)90089-n. [DOI] [PubMed] [Google Scholar]
  18. Skofitsch G., Jacobowitz D. M. Galanin-like immunoreactivity in capsaicin sensitive sensory neurons and ganglia. Brain Res Bull. 1985 Aug;15(2):191–195. doi: 10.1016/0361-9230(85)90135-2. [DOI] [PubMed] [Google Scholar]
  19. Tatemoto K., Rökaeus A., Jörnvall H., McDonald T. J., Mutt V. Galanin - a novel biologically active peptide from porcine intestine. FEBS Lett. 1983 Nov 28;164(1):124–128. doi: 10.1016/0014-5793(83)80033-7. [DOI] [PubMed] [Google Scholar]
  20. Walker M. W., Ewald D. A., Perney T. M., Miller R. J. Neuropeptide Y modulates neurotransmitter release and Ca2+ currents in rat sensory neurons. J Neurosci. 1988 Jul;8(7):2438–2446. doi: 10.1523/JNEUROSCI.08-07-02438.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Wall P. D., Woolf C. J. Muscle but not cutaneous C-afferent input produces prolonged increases in the excitability of the flexion reflex in the rat. J Physiol. 1984 Nov;356:443–458. doi: 10.1113/jphysiol.1984.sp015475. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Wiesenfeld-Hallin Z., Bartfai T., Hökfelt T. Galanin in sensory neurons in the spinal cord. Front Neuroendocrinol. 1992 Oct;13(4):319–343. [PubMed] [Google Scholar]
  23. Wiesenfeld-Hallin Z., Duranti R. D-Arg1, D-Trp7,9, Leu11-substance P (spantide) does not antagonize substance P-induced hyperexcitability of the nociceptive flexion withdrawal reflex in the rat. Acta Physiol Scand. 1987 Jan;129(1):55–59. doi: 10.1111/j.1748-1716.1987.tb08039.x. [DOI] [PubMed] [Google Scholar]
  24. Wiesenfeld-Hallin Z., Villar M. J., Hökfelt T. The effects of intrathecal galanin and C-fiber stimulation on the flexor reflex in the rat. Brain Res. 1989 May 8;486(2):205–213. doi: 10.1016/0006-8993(89)90506-4. [DOI] [PubMed] [Google Scholar]
  25. Wiesenfeld-Hallin Z., Xu X. J., Langel U., Bedecs K., Hökfelt T., Bartfai T. Galanin-mediated control of pain: enhanced role after nerve injury. Proc Natl Acad Sci U S A. 1992 Apr 15;89(8):3334–3337. doi: 10.1073/pnas.89.8.3334. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Wynick D., Smith D. M., Ghatei M., Akinsanya K., Bhogal R., Purkiss P., Byfield P., Yanaihara N., Bloom S. R. Characterization of a high-affinity galanin receptor in the rat anterior pituitary: absence of biological effect and reduced membrane binding of the antagonist M15 differentiate it from the brain/gut receptor. Proc Natl Acad Sci U S A. 1993 May 1;90(9):4231–4235. doi: 10.1073/pnas.90.9.4231. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Xu X. J., Wiesenfeld-Hallin Z., Fisone G., Bartfai T., Hökfelt T. The N-terminal 1-16, but not C-terminal 17-29, galanin fragment affects the flexor reflex in rats. Eur J Pharmacol. 1990 Jun 21;182(1):137–141. doi: 10.1016/0014-2999(90)90502-w. [DOI] [PubMed] [Google Scholar]

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