Local control of veins: biomechanical, metabolic, and humoral aspects.

The incidence of vein diseases (varicosity, thrombophlebitis, phlebosclerosis, orthostatic intolerance) is extremely high. In several countries it may exceed that of the arterial pathology by an order of magnitude. In the last decades, this recognition and the rapid accumulation of experimental data have resulted in a progressive reevaluation of the physiological significance of the venous system, which had been rather neglected earlier by scientists. The major aim of this review is to provide a critical survey of recent selected literature related to different physiological functions of the venous system as well as to biomechanical, metabolic, and humoral (ionic, hormonal) aspects of the local venous control. Local neural control mechanisms, including effects of catecholamines and other transmitters, are regarded to be beyond the scope of this work. At present, the synthesis of information available in the literature meets certain difficulties, because occasionally poorly defined methodological techniques and physiological parameters have been applied. On the other hand, a significant part of works dealing with venous physiology is excellent and inspirational. We have good reason to believe that the fast accumulation of reliable scientific data on this very important field will soon reach a new critical level, then an even more effective integration of knowledge will be possible.