Attenuation of Chemoexcitation Induced by Almitrine Bismesylate in Anaesthetized Cats
During a neuropharmacological investigation on the responsiveness of cat carotid body chemoreceptors to almitrine (McQueen et al., 1989), we noted that the chemoexcitatory action of this peripheral chemoreceptor stimulant tended to be diminished by repeatedly administering 0.5 mg kg−1 i.V. of the drug. Roumy and Leitner (1981) reported that the increase in chemosensory discharge evoked by almitrine (0.75 kg−1i.v.) injected at hourly intervals in rabbits became less and less marked, “as if a kind of tachyphylaxis took place in the preparation”. Hugelin (1981, unpublished results) recorded phrenic nerve activity in anaesthetized and curarized cats and found that the increase in integrated phrenic nerve activity, measured 5 min after an injection, showed tachyphylaxis in response to repeated administration of almitrine (0.5 mg kg−1 i.V.).
KeywordsCarotid Body Sodium Cyanide Locke Solution Phrenic Nerve Activity Arterial Chemoreceptor
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- Docherty, R. J., and McQueen, D. S., 1978, Inhibitory action of dopamine on cat carotid chemoreceptorsJ. Physiol. (Lond.)., 297:425.Google Scholar
- Kirby, G. C., and McQueen, D. S., 1984, Effect of the antagonists MDL72222 and ketanserin on responses of cat carotid body chemoreceptors to 5-hydroxytryptamineBr. J. Pharmacol., 83:259.Google Scholar
- McQueen, D. S., 1977, A quantitative study of the effects of cholinergic drugs on carotid chemoreceptors in the catJ. Physiol. (Lond.)., 273:515.Google Scholar
- McQueen, D. S., 1984, Effects of selective dopamine receptor agonists and antagonists on carotid body chemoreceptor activity, “The Peripheral Arterial Chemoreceptors.” D. J. Fallot, ed., Croom Helm, LondonGoogle Scholar
- McQueen, D. S., Evrard, Y., Gordon, B. H., and Campbell, D. B., 1989, Ganglioglomerular nerves influence responsiveness of cat carotid body chemoreceptors to almitrine, J. Aut. Nerv. Sys., in press.Google Scholar
- O’Regan, R. G., Majcherczyk, S., and Przbyszewski, A., 1983, Effects of almitrine on activities recorded from nerves supplying the carotid bifurcation in the catEur. J. Respir. Pis., 65:Suppl 126:197.Google Scholar
- Fallot, D. J., and Al Neamy, 1983, The effects of hypoxia, hypercapnia and almitrine bismesylate on carotid body catecholaminesEur. J. Respir. Pis., 64:Suppl 126:203.Google Scholar
- Fequignot, J. M., Tavitian, E., Boudet, C., Evrard, Y., Claustre, J., and Feyrin, L., 1987, Inhibitory effect of almitrine on dopaminergic activity of rat carotid bodyJ. Appl. Physiol., 63:746.Google Scholar
- Roumy, M., and Leitner, L.-M., 1981, Stimulant effect of almitrine (S2620) on the rabbit carotid chemoreceptor afferent activity. Bull. Europ. Fhysiopath. Resp., 17:255Google Scholar