RESUMO
Studies were made on the effect of phospholipase A2 on the stability of arterial wall lysosomes, and the influence of glycyrrhizin on this effect. Lysosomal phospholipase A2 activity was found to be increased in the aorta of hypercholesterolemic rats. Treatment of the lysosomal fraction of the arterial wall with venom phospholipase A2 resulted in release of acid phosphatase, and addition of glycyrrhizin (0.1 mM) inhibited this release. Lysosomal phospholipase A2 in the arterial wall was also inhibited dose-dependently by glycyrrhizin. These results suggest that lysis of lysosomes was due to increase in phospholipase A2 activity, and that glycyrrhizin stabilized the lysosomes by inhibiting phospholipase A2 activity.
Assuntos
Aorta/efeitos dos fármacos , Ácido Glicirretínico/análogos & derivados , Lisossomos/efeitos dos fármacos , Fosfatase Ácida/metabolismo , Animais , Aorta/enzimologia , Colesterol/sangue , Colesterol/metabolismo , Colesterol na Dieta/metabolismo , Ácido Glicirretínico/farmacologia , Ácido Glicirrízico , Masculino , Fosfolipases A/farmacologia , Fosfolipases A2 , Ratos , Ratos EndogâmicosRESUMO
The influence of glycyrrhizin on the effect of phospholipase A2 on lysosomes was studied. Treatment of rat liver lysosomes with venom phospholipase A2 caused release of acid phosphatase. This release of acid phosphatase was inhibited by 0.1 mM glycyrrhizin. Glycyrrhizin also inhibited acid phospholipase A2 with pH optimum of 4.5, which is thought to be present in the lysosomal membrane. These results suggest that glycyrrhizin stabilizes lysosomes by inhibiting phospholipase A2 activity in the lysosomal membrane.