Proteinases are enzymes that catalyse the breakdown of proteins. Proteinases are involved in many biological functions, including the digestion of ingested proteins, the breakdown of old proteins, and cell signalling.

In cells D-glucose 6-phosphate (G6P) is generated when glucose is phosphorylated by hexokinase or glucokinase or by the conversion of glucose-1-phosphate by phosphoglucomutase during glycogenolysis. G6P lies at the beginning of both glycolysis and the pentose phosphate pathways. It also can be stored as glycogen when blood glucose levels are high.

Bretylium tosylate is an inhibitor of the presynaptic release of vasoconstrictor neurotransmitters a available antiarrhythmic drug for ventricular arrhythmias.