Abstract
Lens endopeptidase activity and thermal stability have been determined as a function of (1) cell development, (2) cell age, and (3) animal age. Lenses from animals aged 3 months to 15 years (lens weights 1.15–2.80 g) were divided into epithelial (outermost), cortical (peripheral), and nuclear (central) regions. Changes accompanying cell development were determined by measuring specific activity in epithelial (undifferentiated), outer cortical (differentiating), inner cortical (mature) and nuclear (aged) regions of individual lenses. Thermal stability of the enzyme activity obtained from the outer cortical and nuclear regions of the same lenses was also determined. Specific activity and thermal stability were found to decrease as a function of lens cell development. Changes with cell development represent the effects of both differentiation and increasing cell age. To determine the effects of cell age alone, activity was determined in the same population of aged, fully differentiated cells in lenses of different ages. Specific activity decreases as a function of cell age alone. Changes with animal age were determined by comparing cells of the same developmental stage from animals of different ages (e.g., differentiating cells of the cortex in animals 3 months to 15 years old). Specific activity for the cortical region increased with animal age while specific activity in the nuclear region appeared to remain constant or decrease slightly with increasing animal age. Thermal stability of the enzyme activity from the cortex was different in young and adult lenses. The change in stability occurred early in the lifespan and was therefore more closely related to animal development than to aging.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.