Cortisol and lysosomal stability in normal and atheromatous rats

Area of Science:

• Biochemistry
• Cell Biology
• Pharmacology

Background:

• Lysosomal stability is crucial for cellular function.
• Atherogenic diets can compromise lysosomal integrity.
• Cortisol's role in lysosomal stability requires further elucidation.

Purpose of the Study:

• To investigate the impact of cortisol on lysosomal stability in rats.
• To determine if cortisol can counteract diet-induced lysosomal instability.
• To assess the dose-dependent in vitro effects of cortisol on lysosomal enzyme release.

Main Methods:

• Rats were fed normal or atherogenic diets and administered cortisol.
• Beta-glucuronidase was used as a marker for lysosomal enzyme activity.
• Lysosomal enzyme activity was measured in liver, aorta, serum, and subcellular fractions.
• In vitro experiments assessed cortisol's direct effect on isolated lysosomes.

Main Results:

• Cortisol significantly increased intact lysosomal activity and decreased soluble activity in the liver.
• Hepatic lysosomal stability increased, and enzyme release from hepatic and aortic lysosomes decreased with cortisol treatment.
• Cortisol administration restored lysosomal stability in rats fed atherogenic diets.
• In vitro, cortisol reduced enzyme release from hepatic lysosomes in a dose-dependent manner.

Conclusions:

• Cortisol significantly enhances lysosomal stability in rats, irrespective of diet.
• The hormone protects lysosomes from enzyme leakage, particularly evident in liver and aorta.
• Cortisol's stabilizing effect on lysosomes has implications for managing conditions associated with lysosomal dysfunction, such as atherosclerosis.