Summary
The central cardiovascular effects of 4 structural analogues of GABA were investigated. The drugs were injected intracerebroventricularly (i.c.v.) in cumulative doses into pentobarbital-anaesthetized normotensive rats. Muscimol (0.01–10 μg/kg), THIP (0.01–100μg/kg), kojic amine (0.1–100 μg/kg) and isoguvacine (0.1–100μg/kg) produced dose-dependent hypotension and bradycardia. The maximal fall in the mean blood pressure was of about 35% of the initial values. These effects appears to be of central origin since the intravenous (i.v.) injection of the same doses of the drugs did not produce any similar cardiovascular modifications. The hypotensive effects of muscimol and kojic amine were antagonized partly by i.c.v. bicuculline. The combination of bicuculline and kainic acid almost completely prevented the blood pressure lowering effects of muscimol, kojic amine and isoguvacine. THIP however was only slightly antagonized by bicuculline and kainic acid. Atropine i.v. also prevented partly the cardiovascular effects of all these drugs.
Thus, the mechanisms of the central cardiovascular actions of GABA analogues appear to be more complex than expected and variable from one drug to another.
The involvement of GABA receptors of the A and B types and of cholinergic mechanisms in the hypotensive effect of the drugs is discussed.
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References
Antonaccio MJ, Snyder DW (1981) Reduction in blood pressure, heart rate and renal sympathetic nervous discharge after imidazole-4-acetic acid; mediation through central γ-aminobutyric acid (GABA) receptor stimulation. J Pharmacol Exp Ther 218:200–205
Antonaccio MJ, Taylor DG (1977) Involvement of central GABA receptors in the regulation of blood pressure and heart rate of anaesthetized cats. EurjJ Pharmacol 46:283–287
Antonaccio MJ, Kerwin L, Taylor DG (1978) Reductions in blood pressure, heart rate and renal sympathetic nerve discharge in cats after the central administration of muscimol, a GABA agonist. Neuropharmacology 17:783–791
Arnt J, Krogsgaard-Larsen P (1979) GABA agonists and potential antagonists related to muscimol. Brain Res 177:395–400
Atkinson JG, Girard Y, Rokach J, Rooney CS, McFarlane CS, Rackham A, Share NN (1979) Kojic amine. A novel GABA analog. J Med Chem 22:99–106
Bhargava KP, Bhattacharya SS, Srimal RC (1964) Central cardiovascular actions of γ-aminobutyric acid. Br J Pharmacol 23: 383–390
Billingsley ML, Suria A (1982) Effects of peripherally administered GABA and other aminoacids on cardiopulmonary responses in anesthetized rats and dogs. Arch Int Pharmacodyn 255:131–140
Bourne GW, Padjen AL (1980) Kojic amine: a GABA agonist with dual action. Soc Neurosci Abstr Vol 6, p 148
Bousquet P, Bloch R, Feldman J, Schwartz J (1979) The ventromedullary vasomotor centre. In: Meyer PH, Schmitt H (eds) Neurous system and hypertension. Flammarion, Paris, pp 363–370
Bousquet P, Feldman J, Block R, Schwartz J (1981a) Central cardiovascular effects of taurine: comparison with homotaurine and muscimol. J Pharmacol Exp Ther 219:213–218
Bousquet P, Feldman J, Block R, Schwartz J (1981b) The ventromedullary hypotensive effect of muscimol in the anaesthetized cat. Clin Exp Hypertens 3:195–205
Bousquet P, Feldman J, Bloch R, Schwartz J (1981c) The central hypotensive action of baclofen in the anaesthetized cat. Eur J Pharmacol 76:193–201
Bowery NG, Doble A, Hill DR, Hudson AL, Shaw JS, Turnbull MJ (1979) Baclofen: a selective agonist for a novel type of GABA receptor. Br J Pharmacol 67:444P-445P
Bowery NG, Hill DR, Hudson AL, Doble A, Middlemiss DN, Shaw J, Turnbull M (1980) (−)Baclofen decreases neurotransmitter release in the mammalian CNS by an action at a novel GABA receptor. Nature 283:92–94
Chelly J, Kouyoumndjian JC, Mouillé P, Huchet AM, Schmitt H (1979) Effect of l-glutamic acid and kainic acid on central cardiovascular control. Eur J Pharmacol 60:91–94
Curtis DR, Duggan AW, Felix D, Johnston GAR (1970) GABA, bicuculline and central inhibition. Nature 226:1222–1224
Curtis DR, Duggan WA, Felix D, Johnston GAR (1971a) Bicuculline an antagonist of GABA and synaptic inhibition in the spinal cord of the cat. Brain Res 32:69–96
Curtis DR, Duggan AW, Felix D, Johnston GAR, McLennan H (1971b) Antagonism between bicuculline and GABA in the cat brain. Brain Res 33:57–73
De Feudis FV (1982) GABA: an inhibitory neurotransmitter that is involved in cardiovascular control. Pharmacol Res Commun 14:567–575
Desarmenien M, Feltz P, Loeffler JP, Occhipinti G, Santangelo F (1982) Multiple GABA receptors on Aδ and C primary afferent neurones in the adult cat. Br J Pharmacol 76:289P
Elliot KAC, Hobbiger F (1959) γ-Aminobutyric acid: circulatory and respiratory effects in different species; reinvestigation of the anti-strychnine action in mice. J Physiol (Lond) 146:70–84
Enna SJ, Snyder SH (1977) GABA receptor binding in frog spinal cord and brain. J Neurochem 28:857–860
Feldberg W, Guertzenstein PG (1976) Vasodepressor effects obtained by drugs acting on the ventral surface of the brain stem. J Physiol (Lond) 258:337–335
Gillis RA, Williford DJ, Dias Souza J, Quest JA (1982) Central cardiovascular effects produced by the GABA receptor agonist drug, Thip. Neuropharmacology 21:545–547
Greenlee DV, Vanness PC, Olsen RW (1978) γ-Aminobutyric acid binding in mammalian brain; receptor like specificity of sodium independent sites. Neurochemistry 31:933–938
Guertzenstein PG (1973) Blood pressure effects obtained by drugs applied to the ventral surface of the brain stem. J Physiol (Lond) 229:395–408
Hall JG, Hicks TP, McLennan H (1978) Kainic acid and glutamate receptor. Neurosci Lett 8:171–175
Johnston GAR, Beart PM, Curtis DR, Game CJA, McCulloch RM, McLachlan RM (1972) Bicuculline methochloride as a GABA antagonist. Natl New Biol 240:219–220
Johnston GAR, Hailstone MH, Freeman CG (1980) Baclofen: stereoselective inhibition of excitant amino-acid release. J Pharm Pharmacol 32:230–231
Krogsgaard-Larsen P, Falch E (1981) GABA agonists, development and interactions with the GABA receptor complex. Mol Cell Biochem 38:129–146
Krogsgaard-Larsen P, Johnston GAR (1978) Structure activity studies on the inhibition of GABA binding to rat membranes by muscimol and related compounds. Neurochemistry 30:1377–1382
Nadler JV (1979) Minireview on kainic acid: neurophysiological and neurotoxic actions. Life Sci 24:289–300
Olney JW, Rhee V, Ho OL (1974) Kainic acid: a powerful neurotoxic analogue of glutamate. Brain Res 77:507–512
Potashner SJ (1979) Baclofen: effects on amino-acid release and metabolism in slices of guinea-pig cerebral cortex. Neurochemistry 32:103–109
Schmitt H (1977) The pharmacology of clonidine and related products. In: Gross F (ed) Antihypertensive agents. Handbuch der Experimentellen Pharmakologie, vol 39. Springer, Berlin Heidelberg New York, pp 299–396
Scriabine A, Taylor DG Jr, Hong E (1982) Central control of arterial pressure by drugs. Prog Drug Res 26:353–368
Snyder DW, Antonaccio MJ (1980) Central sites involved in the hypotensive effects of muscimol. Brain Res Bull 5:317–323
Stanton HC, Woodhouse FH (1960) The effects of γ-amino-n-butyric acid and some related compounds on the cardiovascular system of anesthetized dogs. J Pharmacol Exp Ther 128:233–242
Sweet CS, Wenger HC, Taylor DA, Gross DM (1980) Central antihypertensive properties of muscimol and related structures. Brain Res Bull 5:491–496
Talman WT, Perrone MH, Reis DJ (1980) Evidence for l-glutamate as the neurotransmitter of primary baroreceptor efferent nerve fibers. Science 209:813–815
Williford DJ, Hamilton BL, Dias Souza J, Williams TP, Dimicco JA, Gillis RA (1980) Central nervous system mechanisms involving GABA influence arterial pressure and heart rate in the cat. Circ Res 47:80–88
Williford DJ, Hamilton BL, DiMicco JA, Wesley PN, Yamada KA, Quest JA, Zavadil A, Gillis RA (1981) Central GABAergic mechanisms involved in the control of arterial blood pressure. In: Buckley JP, Ferrario CM (eds) Central nervous system mechanisms in hypertension. Raven Press, New York, pp 49–60
Yamada KA, Norman WP, Hamosh P, Gillis RA (1982) Medullary ventral surface GABA receptors affect respiratory and cardiovascular function. Brain Res 248:71–78
Yarbrough GG, Williams M, Haubrich DR (1979) The neuropharmacology of a novel-gamma aminobutyric acid analog, kojic amine. Arch Int Pharmacodyn Ther 241:266–279
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Bousquet, P., Feldman, J., Bloch, R. et al. Pharmacological analysis of the central cardiovascular effects of four GABA analogues. Naunyn-Schmiedeberg's Arch. Pharmacol. 325, 291–297 (1984). https://doi.org/10.1007/BF00504371
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DOI: https://doi.org/10.1007/BF00504371