Carbon dioxide formation increases during states of increased oxidative metabolism. It readily diffuses from parenchymal cells where it is produced to the vascular smooth muscle of blood vessels where it causes vasodilation. CO 2 plays a significant role in regulating cerebral blood flow. Hydrogen ion increases when CO 2 increases or during states of increased anaerobic metabolism. Lactic acid , a product of anaerobic metabolism, is a vasodilator, although in large part because of its pH effect.
Inorganic phosphate is released by the hydrolysis of adenine nucleotides.
It may have some vasodilatory activity in contracting skeletal muscle.