Lysosomal Acid Hydrolase Activities in the Lungs of Fetal, Neonatal, Adult, and Senile Mice

Abstract

The activities of four lysosomal acid hydrolases (LAH) in the lungs of two strains of mice changed significantly throughout the life cycle. In the C57B1/6J animals, acid phosphatase (AP) and β-glucuronidase (β-G) were maximally active during early neonatal life then gradually declined to the adult levels by 4–5 weeks of age. After reaching the adult level, acid phosphatase activities did not change significantly through 20 months of age. In contrast, β-G activities increased markedly with advanced age. N-Acetyl-β-D-glucosaminidase (GAD) activities did not change significantly during late fetal, neonatal or young adult stages but increased significantly with advancing age. In the lungs of the CFW animals, the increase in activities of β-G and GAD between young adult life and advanced age was highly significant, whereas there was no notable change in the activities of acid phosphatase or arylsul-fatase (AS). The specific activities of the hydrolases in the lungs of the C57B1/6J strain were quite similar to those in the lungs of the CFW strain. The activities of all four hydrolases were markedly elevated in two spontaneous adenomatous tumors found in the lungs of old mice. The data indicate that LAH play a significant role in lung growth and maturation, and in changes associated with aging.

Anti-tumour activity and toxicity of the new prodrug9-aminocamptothecin glucuronide (9ACG) in mice

“…This was not due to differences in topoisomerase I activity, a determinant of camptothecin cytotoxicity, because 9AC toxicity was independent of age ( Figure 2). bG activity may decrease with age (Traurig, 1976), suggesting that activation of 9ACG by endogenous bG may be responsible for prodrug toxicity in young mice. The high toxicity of 9ACG after i.p.…”

A modified density gradient proteomic-based method to analyze endolysosomal proteins in cardiac tissue

“…The importance of lysosomes in cardiac physiology, both in health and in disease, has long been recognized ( Wildenthal and Decker, 1980 ). Early elegant ultrastructural and biochemical studies investigated the levels of lysosomal enzyme activity in many organs including the heart ( Comolli, 1971 ; Wilson, 1972 ; Youhotsky-Gore and Pathmanathan, 1968 ; Traurig, 1976 ). As early as 1964, an increased number of lysosomes were observed in the atrial muscle of chronically diseased or stressed hearts with acquired heart disease such as mitral stenosis ( Wheat, 1965 ).…”

Cardiac Atrial Compartmentalisation Proteomics: A Modified Density Gradient Method to Analyse Endo-lysosomal Proteins

“…The importance of lysosomes in cardiac physiology, both in health and in disease has long been recognised 18 . Early elegant ultrastructural and biochemical studies investigated the levels of lysosomal enzyme activity in many organs including the heart 19–22 . As early as 1964 an increased number of lysosomes was observed in the atrial muscle of chronically diseased or stressed hearts with acquired heart disease such as mitral stenosis 23 .…”