What is vascular permeability?
Vascular permeability defines the ability of molecules to pass through blood vessels and achieve tissue. The thin layer of cells that form the blood vessels called the endothelium regulates the size of the gas, nutrient and water molecules that can penetrate tissue. For example, vascular permeability of oxygen and carbon dioxide molecules allows easy passage through the endothelium. Larger molecules such as substances soluble in water and water cannot penetrate the walls of blood vessels. These molecules rely on small pores in narrow joints of the blood vessels to achieve tissue.
Several factors determine molecular permeability, which includes complex interactions of chemicals in the human body. Scientists have discovered a peptide identified as a vascular endothelial growth factor (VEGF) as the main determinant of vascular permeability. It acts via dopamine, neurotransmitter in the brain, block or allow molecules from sticking to the wall of blood vessels.
vegf is associated with cancer because Tomohou stimulate cellular receptors and increase vascular permeability raMovin cells into the tissue and bloodstream. Scientists believe that this peptide inhibition can prevent the spread of malignancy with blood. It can also prevent fluid from being built around the heart, where dopamine also regulates the vascular permeability of the fluid in the arteries.
Animal studies using certain antibodies show some control of permeability in colon cancer, brain and breast cancer. These tests used dyeing and magnetic resonance imaging (MRI) to measure the number of cancer cells that exceeded the blood/brain barrier. Scientists found some success in changing the movement of cancer cells through the walls of blood vessels.
Studies on vascular permeability also helped to develop drugs capable of crossing the blood/brain barrier to treat the disease. Scientists initially found that the disruption of this barrier opened the way for Other toxins to enter the bloodstream. This led to the discovery of chemotherapeuticH of fabrics capable of selectively cross the barrier only where there is a tumor.
The use of heat can increase vascular permeability in tumor points. Hypertermia increases the size of the pores in blood vessels that feed on tumors, which could enable the heat sensitive to enter malignancy. Along with cancer, increased vascular permeability of drugs effective to treat diabetes, arthritis and heart disease.