Skeletal muscle blood flow is closely coupled to metabolic demand, and its regulation is believed to be mainly the result of the interplay of neural vasoconstrictor activity and locally derived vasoactive substances. Muscle blood flow is increased within the first second after a single contraction and stabilizes within approximately 30 s during dynamic exercise under normal conditions. Vasodila...

BACKGROUND Carcinoid tumor, benign, low-grade malignant, and high-grade malignant, can be associated with the release of vasoactive substances that cause symptoms including cutaneous flushing, diarrhea, and bronchospasm. In 50-60% of patients with carcinoid syndrome, the vasoactive substances cause fibrosis of the pulmonary and tricuspid heart valves which lead to regurgitation and right-sided ...

To elucidate the differential reactivity of pulmonary microvessels in the acini to hypoxia, excessive CO2, and increased H+, we investigated changes in the diameter of precapillary arterioles, postcapillary venules, and capillaries in isolated rat lungs on exposure to normocapnic hypoxia (2% O2), normoxic hypercapnia (15% CO2), and isocapnic acidosis (0.01 mol/L HCl). Microvascular diameters we...

The measurement of pulmonary metabolism of three vasoactive substances and quantitative assessment of changes in lung morphology were performed in a long-term study of asbestos-exposed guinea pigs. Animals received intratracheal injections of a single dose of a sterile suspension of Canadian chrysotile B (5 mg), while control animals received only saline. Six months after the treatment, the gui...

Inflammation is a very complicated phenomenon and consist a part of the immune response which is divided to a natural phase followed by an adaptive one. Tissue injury is followed by a cascade of events leading to the inflammatory response which is divided in three phases. The first phase of inflammation is manifested by the activation of the local tissue macrophagues which exert their phagocyti...

Carcinoid is a rare tumor originating from neuroendocrine cells, which are generally localized in the gastrointestinal tract. It has an annual incidence of 1.5 persons per 100 000. Usually, only carcinoid tumors that invade the liver result in pathological changes to the heart. The cardiac manifestations are caused by paraneoplastic effects of vasoactive substances such as serotonin, bradykinin...

The endothelium regulates the concentrations of several types of vasoactive substances that affect pulmonary vascular tone, and endothelia can oppose vasoconstriction in some circumstances by releasing vasodilators. To assess some of these endothelial functions in patients with pulmonary hypertension, we made measurements of selected vasoactive substances before and during attempts at pharmacol...