PMID: 36458Apr 1, 1979

The effects of treatment and of withdrawal of treatment with guanfacine and clonidine on blood pressure and heart rate in normotensive and renal hypertensive rats

The Journal of Pharmacy and Pharmacology
R Salzmann

Abstract

Disagreement in the literature about the occurrence of rebound hypertension (hypertensive overshoot) in animal models initiated this investigation. Oral doses of clonidine (0.03 mg kg-1) or guanfacine (0.3 mg kg-1) were administered twice daily during three weeks to groups of normotensive and renal hypertensive rats. Blood pressure and heart rate were measured immediately before and 3 h after the first daily dose, and compared with values obtained from placebo-treated control rats. Treatment with either drug induced large daily fluctuations rather than sustained falls in blood pressure. In the normotensive, but not in the hypertensive groups, the morning blood pressures measured before the first daily dose were significantly elevated over those of the control groups after 9 and 5 days of treatment with clonidine or guanfacine. This elevation persisted for 3 days after drug withdrawal. It is concluded that in the rat the duration of action of both drugs was short, so that twice daily administration of both drugs similarly produced large daily fluctuations rather than sustained falls in blood pressure. Blood pressure rises developed during treatment rather than after withdrawal in normotensive rats only. Therefore, this type of s...Continue Reading

References

Jul 15, 1977·European Journal of Pharmacology·R K Dix, E M Johnson
Mar 1, 1978·Clinical and Experimental Pharmacology & Physiology·H F OatesG S Stokes
Mar 1, 1980·Clinical and Experimental Pharmacology & Physiology·G S StokesH F Oates
Apr 1, 1949·Proceedings of the Society for Experimental Biology and Medicine·M FRIEDMAN, S C FREED

Citations

Jan 1, 1982·Psychopharmacology·W L WoolvertonR L Balster
Jan 1, 1981·European Journal of Clinical Pharmacology·A J BuneL M Wing
Jan 1, 1982·General Pharmacology·M Parker, J Atkinson
Nov 1, 1982·Clinical and Experimental Pharmacology & Physiology·M ParkerJ Atkinson
Jan 1, 1995·Clinical and Experimental Pharmacology & Physiology. Supplement·R IshiiK Namba
Jan 1, 1984·Clinical and Experimental Hypertension. Part A, Theory and Practice·B JarrottW J Louis
Jan 1, 1982·Clinical and Experimental Hypertension. Part A, Theory and Practice·K SaameliG Scholtysik
Jan 1, 1982·Clinical and Experimental Hypertension. Part A, Theory and Practice·E L Conway, B Jarrott
Nov 1, 1980·American Heart Journal·G S StokesE P MacCarthy
Apr 1, 1981·The Journal of Pharmacy and Pharmacology·M J ThoolenP A Van Zwieten
Oct 4, 1980·The Medical Journal of Australia·P J Miach, W J Louis

Related Concepts

Antihypertensive Agents
Diastolic Blood Pressure
Isoglaucon
Guanidines
Pulse Rate
Renal Hypertension
Phenylacetic Acids
Withdrawal Symptoms

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