Abstract
In rats, the existence of circadian rhythms in many physiological, biochemical and behavioural systems has been well established (Sheving et al, 1968; Rusak and Zucker, 1975; Rosenfeld and Rice, 1979). However, controversy exists as to whether or not such rhythms exist for arterial blood pressure. Although Friberg et al (1982) reported that the blood pressure of normotensive rats was higher during the dark phase than the light phase, Norman et al (1980) did not find evidence for a circadian rhythm in this parameter. Nevertheless, it appears that the cardiovascular effects of drugs could be complicated by the presence of circadian rhythms in vagal and sympathetic activity, hormone release and the responsiveness of the heart and blood vessels (Rusak and Zuker, 1979; Hossman et al., 1980). For example, Brown and Lever (1982) demonstrated that the pressor effects of a continuous infusion of angiotensin II in normotensive rats were more dramatic during the dark phases of a four day infusion period.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Reference
Brown, A.J. and Lever, A.F. (1982). A slow rise of arterial pressure with increased diurnal variation produced by saralasin and by angiotensin II in the conscious rat. In Hypertensive Mechanisms (eds. W. Rascher, D. Clough and D. Ganten) pp 400–404, Schattauer-Verlag, Stuttgart.
Friberg, P., Hallback-Nordlender, M., Karlsson, B. and Ljung, B. (1982). Circadian rhythm of arterial blood pressure and heart rate in spontaneously hypertensive rats and normotensive control rats. In Hypertensive Mechanisms (eds. W. Rascher, D. Clough and D. Ganten) pp 361–363, Schattauer-Verlag, Stuttgart.
Hossman, V., Fitzgerald, G.H. and Dollery, C.T. (1980). Circadian rhythm of baroreflex reactivity and adrenergic vascular response. Cardiovasc. Res., 14, 125–129.
Kafka, M.S., Wirz-Justice, A. and Naber, D. (1981). Circadian and seasonal rhythms in alpha and beta adrenergic receptors in the rat brain. Brain Res., 127, 409–419.
Kleinlogel, H., Scholtysik, C. and Sayers, A.C. (1975). Effects of clonidine and BS 100–141 on the EEG sleep patterns in rat. Eur. J. Pharmacol., 33, 159–163.
Rosenfeld, J.P. and Rice, P.E. (1979). Diurnal rhythms in nociceptive threshold in rats. Physiol. Behav., 22, 419–420.
Rusak, B. and Zucker, I. (1975). Biological rhythms and animal behaviour. Ann. Rev. Psychol., 26, 137–171.
Schmitt, H. (1977). The pharmacology of clonidine and related products. In The Handbook of Experimental Pharmacology. Vol. XXXIX (ed. F. Gross) pp 229–369, Springer-Verlag, Berlin.
Sheving, L.E., Harrison, W.H., Gordon, P. and Pauly, J.E. (1968). Daily fluctuations in biogenic amines on the rat brain. Am. J. Physiol., 214, 166–173.
Editor information
Editors and Affiliations
Copyright information
© 1985 The Contributors
About this chapter
Cite this chapter
Lewis, S.J., Jarrott, B. (1985). The Effects of Continuous Clonidine Infusion on the Circadian Rhythms of Arterial Blood Pressure, Heart Rate and Spontaneous Locomotor Activity in Normotensive Wistar-Kyoto Rats. In: Redfern, P.H., Campbell, I.C., Davies, J.A., Martin, K.F. (eds) Circadian Rhythms in the Central Nervous System. Satellite Symposia of the IUPHAR 9th International Congress of Pharmacology. Palgrave Macmillan, London. https://doi.org/10.1007/978-1-349-07837-0_19
Download citation
DOI: https://doi.org/10.1007/978-1-349-07837-0_19
Publisher Name: Palgrave Macmillan, London
Print ISBN: 978-1-349-07839-4
Online ISBN: 978-1-349-07837-0
eBook Packages: Biomedical and Life SciencesBiomedical and Life Sciences (R0)