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. 1991 Nov;104(3):629–632. doi: 10.1111/j.1476-5381.1991.tb12480.x

Furosemide inhibits the centrally-mediated pressor response to clonidine in conscious, normotensive rats.

H Kawasaki 1, S Nakamura 1, K Takasaki 1
PMCID: PMC1908240  PMID: 1797326

Abstract

1. The effect of furosemide on the pressor response induced by intracerebroventricular (i.c.v.) injection of clonidine was investigated in freely moving, normotensive rats with chronically implanted arterial catheters. 2. When injected i.c.v., clonidine at doses of 5 and 10 micrograms produced a dose-dependent pressor response and a decrease in heart rate. No depressor response was induced by clonidine. 3. Systemic (i.v.) pretreatment with furosemide (2-10 mg kg-1) increased urine volume and dose-dependently inhibited the pressor response to i.c.v. clonidine (10 micrograms), and a long-lasting depressor response to clonidine was observed. However, furosemide treatment did not alter the bradycardia produced in response to clonidine. 4. The systemic treatment with furosemide (10 mg kg-1, i.v.) had no effect on the pressor response to i.v. noradrenaline. 5. These results suggest that reduction of body fluid volume inhibits the centrally-mediated pressor response to clonidine and leads to the hypotensive effect. We also suggest that combined treatment with a diuretic increases the hypotensive efficacy of clonidine.

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Selected References

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  1. Armstrong J. M., Lefèvre-Borg F., Scatton B., Cavero I. Urethane inhibits cardiovascular responses mediated by the stimulation of alpha-2 adrenoceptors in the rat. J Pharmacol Exp Ther. 1982 Nov;223(2):524–535. [PubMed] [Google Scholar]
  2. Bousquet P., Feldman J., Schwartz J. Central cardiovascular effects of alpha adrenergic drugs: differences between catecholamines and imidazolines. J Pharmacol Exp Ther. 1984 Jul;230(1):232–236. [PubMed] [Google Scholar]
  3. Diop L., Parini A., Dausse J. P., Ben-Ishay D. Cerebral and renal alpha-adrenoceptors in Sabra hypertensive (SBH) and normotensive (SBN) rats: effects of high-sodium diet. J Cardiovasc Pharmacol. 1984;6 (Suppl 5):S742–S747. doi: 10.1097/00005344-198400065-00003. [DOI] [PubMed] [Google Scholar]
  4. Epstein Y., Castel M., Glick S. M., Sivan N., Ravid R. Changes in hypothalamic and extra-hypothalamic vasopressin content of water-deprived rats. Cell Tissue Res. 1983;233(1):99–111. doi: 10.1007/BF00222235. [DOI] [PubMed] [Google Scholar]
  5. Florio V., Bianchi L., Lonogo V. G. A study of the central effects of sympathomimetic drugs: EEG and behavioural investigations on clonidine and naphazoline. Neuropharmacology. 1975 Oct;14(10):707–714. doi: 10.1016/0028-3908(75)90095-7. [DOI] [PubMed] [Google Scholar]
  6. Hui T. P., Krakoff L. R., Felton K., Yeager K. Diuretic treatment alters clonidine suppression of plasma norepinephrine. Hypertension. 1986 Apr;8(4):272–276. doi: 10.1161/01.hyp.8.4.272. [DOI] [PubMed] [Google Scholar]
  7. Janiak P., Kasson B. G., Brody M. J. Central vasopressin raises arterial pressure by sympathetic activation and vasopressin release. Hypertension. 1989 Jun;13(6 Pt 2):935–940. doi: 10.1161/01.hyp.13.6.935. [DOI] [PubMed] [Google Scholar]
  8. Kawasaki H., Takasaki K. Central alpha-2 adrenoceptor-mediated hypertensive response to clonidine in conscious, normotensive rats. J Pharmacol Exp Ther. 1986 Mar;236(3):810–818. [PubMed] [Google Scholar]
  9. Kawasaki H., Takasaki K. Effect of water deprivation on the centrally-mediated hypertensive response to clonidine in freely moving, normotensive rats. Life Sci. 1987 May 11;40(19):1929–1935. doi: 10.1016/0024-3205(87)90053-1. [DOI] [PubMed] [Google Scholar]
  10. Kawasaki H., Takasaki K. Evidence for central alpha 2-adrenoceptor-mediated hypertension in freely moving, normotensive rats. Arch Int Pharmacodyn Ther. 1987 Oct;289(2):217–233. [PubMed] [Google Scholar]
  11. Kawasaki H., Watanabe S., Ueki S. Effects of psychotropic drugs on pressor and behavioral responses to brain stimulation in unrestrained, unanesthetized rats. Pharmacol Biochem Behav. 1979 Jun;10(6):907–915. doi: 10.1016/0091-3057(79)90066-2. [DOI] [PubMed] [Google Scholar]
  12. Kawasaki H., Yamamoto R., Takasaki K. Possible mechanisms underlying the hypertensive response to clonidine in freely moving, normotensive rats. Jpn J Pharmacol. 1986 Nov;42(3):405–417. doi: 10.1254/jjp.42.405. [DOI] [PubMed] [Google Scholar]
  13. Kobinger Central alpha-adrenergic systems as targets for hypotensive drugs. Rev Physiol Biochem Pharmacol. 1978;81:39–100. doi: 10.1007/BFb0034091. [DOI] [PubMed] [Google Scholar]
  14. Kostowski W., Dyr W., Zacharski B. A study of the effects of clonidine on the EEG in rats treated with single and multiple doses of antidepressants. Psychopharmacology (Berl) 1984;84(1):85–90. doi: 10.1007/BF00432031. [DOI] [PubMed] [Google Scholar]
  15. Lehmann J., Koenig-Bérard E., Vitou P. The imidazoline-preferring receptor. Life Sci. 1989;45(18):1609–1615. doi: 10.1016/0024-3205(89)90270-1. [DOI] [PubMed] [Google Scholar]
  16. Rosenman R. H. Combined clonidine-chlorthalidone therapy in hypertension. Two years' experience in 30 patients. Arch Intern Med. 1975 Sep;135(9):1236–1239. [PubMed] [Google Scholar]
  17. Woodcock E. A., Murley B. Increased central alpha-2 adrenergic receptors measured with [3H] yohimbine in the presence of sodium ion and guanylnucleotides. Biochem Biophys Res Commun. 1982 Mar 15;105(1):252–258. doi: 10.1016/s0006-291x(82)80038-7. [DOI] [PubMed] [Google Scholar]

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