<P> A significant part of the clinically approved drugs are lipophilic weak bases with lysosomotropic properties . This explains a number of pharmacological properties of these drugs, such as high tissue - to - blood concentration gradients or long tissue elimination half - lifes; these properties have been found for drugs such as haloperidol, levomepromazine, and amantadine . However, high tissue concentrations and long elimination half - lives are explained also by lipophilicity and absorption of drugs to fatty tissue structures . Important lysosomal enzymes, such as acid sphingomyelinase, may be inhibited by lysosomally accumulated drugs . Such compounds are termed FIASMAs (functional inhibitor of acid sphingomyelinase) and include for example fluoxetine, sertraline, or amitriptyline . </P> <P> Ambroxol is a lysosomotropic drug of clinical use to treat conditions of productive cough for its mucolytic action . Ambroxol triggers the exocytosis of lysosomes via neutralization of lysosomal pH and calcium release from acidic calcium stores . Presumably for this reason, Ambroxol was also found to improve cellular function in some disease of lysosomal origin such as Parkinson's or lysosomal storage disease . </P> <P> By scientific convention, the term lysosome is applied to those vesicular organelles only in animals, and vacuoles to plants, fungi and algae . Discoveries in plant cells since the 1970s started to challenge this definition . Plant vacuoles are found to be much more diverse in structure and function than previously thought . Some vacuoles contain their own hydrolytic enzymes and perform the classic lysosomal activity, which is autophagy . These vacuoles are therefore seen as fulfilling the role of the animal lysosome . Based on de Duve's description that "only when considered as part of a system involved directly or indirectly in intracellular digestion does the term lysosome describe a physiological unit", some botanists strongly argued that these vacuoles are lysosomes . However, this is not universally accepted as the vacuoles are strictly not similar to lysosomes, such as in their specific enzymes and lack of phagocytic functions . Vacuoles do not have catabolic activity and do not undergo exocytosis as lysosomes do . </P> <P> The word lysosome (/ ˈlaɪsoʊsoʊm /, / ˈlaɪzəzoʊm /) is New Latin that uses the combining forms lyso - (referring to lysis and derived from the Latin lysis, meaning "to loosen", via Ancient Greek λύσις (lúsis)), and - some, from soma, "body", yielding "body that lyses" or "lytic body". The adjectival form is lysosomal . The forms * lyosome and * lyosomal are much rarer; they use the lyo - form of the prefix but are often treated by readers and editors as mere unthinking replications of typos, which has no doubt been true as often as not . </P>

What reactions are performed by hydrolytic enzymes in the lysosome