cGMP stands for Cyclic Guanosine Monophosphate. It is a signaling molecule that is involved in regulating a number of physiological processes, including blood flow, smooth muscle relaxation, and cell division. In the context of blood flow regulation, cGMP acts as a second messenger, transmitting signals from the cells’ surface receptors to the inside of the cell to produce a response. For example, in the penis, the release of nitric oxide (NO) stimulates the production of cGMP, which leads to relaxation of the smooth muscle in the walls of blood vessels, increasing blood flow and producing an erection. PDE5 (Phosphodiesterase type 5) is an enzyme that breaks down cGMP, so inhibition of PDE5 can increase the concentration of cGMP, leading to increased smooth muscle relaxation and improved blood flow.
