Key Event Title
|Level of Biological Organization|
Key Event Components
|increased systemic vascular resistance||increased|
Key Event Overview
AOPs Including This Key Event
|AOP Name||Role of event in AOP|
|Homo sapiens||Homo sapiens||High||NCBI|
|Rattus norvegicus||Rattus norvegicus||Low||NCBI|
|All life stages||High|
Key Event Description
Vascular resistance is the resistance to blood flow in the circulatory system (Siddiqui, 2011). Systemic vascular resistance (SVR), also known as total peripheral resistance, refers specifically to the resistance to blood flow offered by the peripheral circulation. Vasodilation decreases SVR while vasoconstriction or impaired vasodilation increases SVR.
How It Is Measured or Detected
Vascular resistance cannot be measured by any direct means, but can be calculated using a formula: (mean arterial pressure minus mean right arterial pressure) divided by cardiac output (Siddiqui 2011).
Domain of Applicability
Increased SVR was observed in humans, pigs and rats (Siddiqui 2011, Dikalova et al. 2016,
Siddiqui, A. (2011). Effects of Vasodilation and Arterial Resistance on Cardiac Output. J. Clin. Exp. Cardiol. 02.
Dikalova A, Aschner JL, Kaplowitz MR, Summar M, Fike CD. Tetrahydrobiopterin oral therapy recouples eNOS and ameliorates chronic hypoxia-induced pulmonary hypertension in newborn pigs. Am J Physiol Lung Cell Mol Physiol. 2016, 1;311(4):L743-L753.