Abstract
A new arylamino-pyridazine gamma-aminobutyric acid (GABA) derivative, SR 42641, has been tested for its ability to antagonize the actions of GABA on mammalian sensory neurones. SR 42641 and bicuculline reversibly decreased GABAA-induced depolarizations and currents recorded intracellularly from dorsal root ganglion neurons (DRG). Dose-response curves were shifted to the right in a parallel fashion. KB values (determined under voltage clamp conditions) were respectively 0.12 +/- 0.05 and 0.38 +/- 0.08 microM. Similar values were obtained with current clamp recording conditions. The study of the GABA-induced Cl- current under voltage-clamp conditions did not show any voltage-dependency of the antagonist effect of SR 42641. In nodose ganglion neurones, SR 42641 (0.4-4.5 microM) did not alter the (-)-baclofen-induced shortening of the calcium component of action potentials. At concentrations higher than 10 microM, SR 42641 itself prolonged calcium-dependent action potentials. Patch-clamp recordings from DRG cultured neurones indicated that SR 42641 did not affect the calcium current responsible for sustained calcium entry into cells. We conclude that SR 42641 is a potent competitive GABA antagonist, specific for the GABAA receptor. It does not act at the level of the chloride ionophore.
Full text
PDF











Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barker J. L., McBurney R. N., Mathers D. A. Convulsant-induced depression of amino acid responses in cultured mouse spinal neurones studied under voltage clamp. Br J Pharmacol. 1983 Dec;80(4):619–629. doi: 10.1111/j.1476-5381.1983.tb10051.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Biscoe T. J., Duggan A. W., Lodge D. Antagonism between bicuculline, strychnine, and picrotoxin and depressant amino-acids in the rat nervous system. Comp Gen Pharmacol. 1972 Dec;3(12):423–433. doi: 10.1016/0010-4035(72)90056-0. [DOI] [PubMed] [Google Scholar]
- Bossu J. L., Feltz A. Inactivation of the low-threshold transient calcium current in rat sensory neurones: evidence for a dual process. J Physiol. 1986 Jul;376:341–357. doi: 10.1113/jphysiol.1986.sp016157. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bossu J. L., Feltz A. Patch-clamp study of the tetrodotoxin-resistant sodium current in group C sensory neurones. Neurosci Lett. 1984 Oct 12;51(2):241–246. doi: 10.1016/0304-3940(84)90558-5. [DOI] [PubMed] [Google Scholar]
- Bossu J. L., Feltz A., Thomann J. M. Depolarization elicits two distinct calcium currents in vertebrate sensory neurones. Pflugers Arch. 1985 Apr;403(4):360–368. doi: 10.1007/BF00589247. [DOI] [PubMed] [Google Scholar]
- Braestrup C., Nielsen M. Interaction of pitrazepin with the GABA/benzodiazepine receptor complex and with glycine receptors. Eur J Pharmacol. 1985 Nov 26;118(1-2):115–121. doi: 10.1016/0014-2999(85)90669-7. [DOI] [PubMed] [Google Scholar]
- Chambon J. P., Feltz P., Heaulme M., Restle S., Schlichter R., Biziere K., Wermuth C. G. An arylaminopyridazine derivative of gamma-aminobutyric acid (GABA) is a selective and competitive antagonist at the GABAA receptor site. Proc Natl Acad Sci U S A. 1985 Mar;82(6):1832–1836. doi: 10.1073/pnas.82.6.1832. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Curtis D. R., Malik R. Glycine antagonism by RU 5135. Eur J Pharmacol. 1985 Apr 16;110(3):383–384. doi: 10.1016/0014-2999(85)90569-2. [DOI] [PubMed] [Google Scholar]
- Deisz R. A., Lux H. D. gamma-Aminobutyric acid-induced depression of calcium currents of chick sensory neurons. Neurosci Lett. 1985 May 14;56(2):205–210. doi: 10.1016/0304-3940(85)90130-2. [DOI] [PubMed] [Google Scholar]
- Desarmenien M., Feltz P., Headley P. M. Does glial uptake affect GABA responses? AN intracellular study on rat dorsal root ganglion neurones in vitro. J Physiol. 1980 Oct;307:163–182. doi: 10.1113/jphysiol.1980.sp013429. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Desarmenien M., Feltz P., Headley P. M., Santangelo F. SL 75 102 as a gama-aminobutyric acid agonist: experiments on dorsal root ganglion neurones in vitro. Br J Pharmacol. 1981 Feb;72(2):355–364. doi: 10.1111/j.1476-5381.1981.tb09135.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dolphin A. C., Scott R. H. Inhibition of calcium currents in cultured rat dorsal root ganglion neurones by (-)-baclofen. Br J Pharmacol. 1986 May;88(1):213–220. doi: 10.1111/j.1476-5381.1986.tb09489.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Désarmenien M., Feltz P., Occhipinti G., Santangelo F., Schlichter R. Coexistence of GABAA and GABAB receptors on A delta and C primary afferents. Br J Pharmacol. 1984 Feb;81(2):327–333. doi: 10.1111/j.1476-5381.1984.tb10082.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldinger A., Müller W. E. Stereospecific interaction of bicuculline with specific [3H]strychnine binding to rat spinal cord synaptosomal membranes. Neurosci Lett. 1980 Jan;16(1):91–95. doi: 10.1016/0304-3940(80)90107-x. [DOI] [PubMed] [Google Scholar]
- Gray R., Johnston D. Rectification of single GABA-gated chloride channels in adult hippocampal neurons. J Neurophysiol. 1985 Jul;54(1):134–142. doi: 10.1152/jn.1985.54.1.134. [DOI] [PubMed] [Google Scholar]
- Gähwiler B. H., Maurer R., Wüthrich H. J. Pitrazepin, a novel GABAA antagonist. Neurosci Lett. 1984 Apr 6;45(3):311–316. doi: 10.1016/0304-3940(84)90244-1. [DOI] [PubMed] [Google Scholar]
- Hamill O. P., Bormann J., Sakmann B. Activation of multiple-conductance state chloride channels in spinal neurones by glycine and GABA. 1983 Oct 27-Nov 2Nature. 305(5937):805–808. doi: 10.1038/305805a0. [DOI] [PubMed] [Google Scholar]
- Hamill O. P., Marty A., Neher E., Sakmann B., Sigworth F. J. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. doi: 10.1007/BF00656997. [DOI] [PubMed] [Google Scholar]
- Heaulme M., Chambon J. P., Leyris R., Molimard J. C., Wermuth C. G., Biziere K. Biochemical characterization of the interaction of three pyridazinyl-GABA derivatives with the GABAA receptor site. Brain Res. 1986 Oct 8;384(2):224–231. doi: 10.1016/0006-8993(86)91158-3. [DOI] [PubMed] [Google Scholar]
- Heyer E. J., Nowak L. M., Macdonald R. L. Membrane depolarization and prolongation of calcium-dependent action potentials of mouse neurons in cell culture by two convulsants: bicuculline and penicillin. Brain Res. 1982 Jan 28;232(1):41–56. doi: 10.1016/0006-8993(82)90609-6. [DOI] [PubMed] [Google Scholar]
- Holz G. G., 4th, Rane S. G., Dunlap K. GTP-binding proteins mediate transmitter inhibition of voltage-dependent calcium channels. Nature. 1986 Feb 20;319(6055):670–672. doi: 10.1038/319670a0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hunt P., Clements-Jewery S. A steroid derivative, R 5135, antagonizes the GABA/benzodiazepine receptor interaction. Neuropharmacology. 1981 Apr;20(4):357–361. doi: 10.1016/0028-3908(81)90009-5. [DOI] [PubMed] [Google Scholar]
- Lee K. S., Marban E., Tsien R. W. Inactivation of calcium channels in mammalian heart cells: joint dependence on membrane potential and intracellular calcium. J Physiol. 1985 Jul;364:395–411. doi: 10.1113/jphysiol.1985.sp015752. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leigh P. J., MacDermot J. Desensitization of prostacyclin responsiveness in a neuronal hybrid cell line: selective loss of high affinity receptors. Br J Pharmacol. 1985 May;85(1):237–247. doi: 10.1111/j.1476-5381.1985.tb08852.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nowycky M. C., Fox A. P., Tsien R. W. Three types of neuronal calcium channel with different calcium agonist sensitivity. Nature. 1985 Aug 1;316(6027):440–443. doi: 10.1038/316440a0. [DOI] [PubMed] [Google Scholar]
- Olsen R. W., Bergman M. O., Van Ness P. C., Lummis S. C., Watkins A. E., Napias C., Greenlee D. V. gamma-Aminobutyric acid receptor binding in mammalian brain. Heterogeneity of binding sites. Mol Pharmacol. 1981 Mar;19(2):217–227. [PubMed] [Google Scholar]
- Segal M., Barker J. L. Rat hippocampal neurons in culture: properties of GABA-activated Cl- ion conductance. J Neurophysiol. 1984 Mar;51(3):500–515. doi: 10.1152/jn.1984.51.3.500. [DOI] [PubMed] [Google Scholar]
- Simmonds M. A. Evidence that bicuculline and picrotoxin act at separate sites to antagonize gamma-aminobutyric acid in rat cuneate nucleus. Neuropharmacology. 1980 Jan;19(1):39–45. doi: 10.1016/0028-3908(80)90164-1. [DOI] [PubMed] [Google Scholar]
- Simmonds M. A., Turner J. P. Antagonism of inhibitory amino acids by the steroid derivative RU5135. Br J Pharmacol. 1985 Mar;84(3):631–635. doi: 10.1111/j.1476-5381.1985.tb16143.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Simonds W. F., DeGroat W. C. Antagonism by picrotoxin of 5-hydroxytryptamine-induced excitation of primary afferent neurons. Brain Res. 1980 Jun 23;192(2):592–591. doi: 10.1016/0006-8993(80)90913-0. [DOI] [PubMed] [Google Scholar]
- Squires R. F., Casida J. E., Richardson M., Saederup E. [35S]t-butylbicyclophosphorothionate binds with high affinity to brain-specific sites coupled to gamma-aminobutyric acid-A and ion recognition sites. Mol Pharmacol. 1983 Mar;23(2):326–336. [PubMed] [Google Scholar]
- Ticku M. K., Ban M., Olsen R. W. Binding of [3H]alpha-dihydropicrotoxinin, a gamma-aminobutyric acid synaptic antagonist, to rat brain membranes. Mol Pharmacol. 1978 May;14(3):391–402. [PubMed] [Google Scholar]
- Wilson W. A., Goldner M. M. Voltage clamping with a single microelectrode. J Neurobiol. 1975 Jul;6(4):411–422. doi: 10.1002/neu.480060406. [DOI] [PubMed] [Google Scholar]
- Yasui S., Ishizuka S., Akaike N. GABA activates different types of chloride-conducting receptor-ionophore complexes in a dose-dependent manner. Brain Res. 1985 Sep 30;344(1):176–180. doi: 10.1016/0006-8993(85)91206-5. [DOI] [PubMed] [Google Scholar]
