Spermidine synchronizes an array of biological processes, (such as Ca2+, Na+, K+ -ATPase) thus maintaining membrane potential and controlling intracellular pH and volume. Spermidine regulates biological processes, such as Ca2+ influx by glutamatergic NMDA receptor, which has been associated with nitric oxide synthase and cGMP/PKG pathway activation and a decrease of Na+,K+-ATPase activity in cerebral cortex synaptosomes.
Spermidine is an aliphatic polyamine found in ribosomes and living tissues and produced naturally within the body. It has various metabolic functions within organisms. It was originally isolated from semen, hence the name. It is also present ubiquitously in foods, as well as in breast milk. Spermidine is a longevity agent in mammals due to various mechanisms of action, which are just beginning to be understood. Autophagy is the main mechanism at the molecular level, but evidence has been found for other mechanisms.