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Acta Physiologica 2012; Volume 206, Supplement 693
Joint FEPS and Spanish Physiological Society Scientific Congress 2012
9/8/2012-9/11/2012
Santiago de Compostela, Spain
CONTRACTILE PROPERTIES OF CONDUIT ARTERIES IN DIFFERENT MODELS OF EXPERIMENTAL HYPERTENSION
Abstract number: P85
Zemancikova1 A, Torok1 J, Bednarova2 K, Simko2 F
1Laboratory of Vascular Disorders Etiopathogenesis, Institute of Normal and Pathological Physiology, Slovak Academy of Sciences,
2Institute of Pathophysiology, School of Medicine, Comenius University
Objectives:
The goal of this study was to demonstrate that the large conduit arteries from hypertensive individuals may not exhibit enhanced contractions in vitro, as is often proclaimed. We aimed to compare the sensitivity and contractile force development in response to vasoconstrictors in large arteries isolated from normotensive and hypertensive rats.
Materials:
Hypertension in rats was either genetically determined (spontaneously hypertensive rats; SHR) or induced exogenously – by chronic Nω-nitro-L-arginine methyl ester (L-NAME) administration (40 mg/kg/day) or by long-term exposure to continuous light (24 h/day) in normotensive Wistar rats. In our functional studies, rings of isolated thoracic aorta and superior mesenteric artery were suspended in organ baths containing modified Krebs solution and connected to a force-displacement transducer for the recording of isometric tension.
Results:
In response to noradrenaline, thoracic aortas from SHR, L-NAME-treated and continuous light-exposed hypertensive rats exhibited greater sensitivity comparing to normotensive Wistar rats. The maximal contractile force expressed in absolute values was markedly reduced in SHR and in L-NAME-treated rats, but not in animals with light-evoked hypertension. In contrast, superior mesenteric arteries of all rat groups produced very similar contractions; only the absolute maximal responses to noradrenaline and to 100 mmol/l KCl were reduced in rats with hypertension induced by L-NAME administration. Only the neurogenic contractions (evoked by endogenous noradrenaline released from electrically stimulated perivascular nerves) were increased in mesenteric arteries from SHR and from continuous light-exposed hypertensive rats.
Conclusions:
These results indicate that in various rat models of hypertension, elevated blood pressure leads to specific biomechanical alterations in large conduit arteries which are reflected in different modification in their contractile properties.
Supported by grants VEGA No. 1/0187/11 and No. 2/0188/12.
To cite this abstract, please use the following information:
Acta Physiologica 2012; Volume 206, Supplement 693 :P85