Histochemical and Biochemical Ontogenic Study in Skin Aging

The skin is one of the largest and widest organ of the body, it consists of two main parts, epidermis and dermis. Aging has many effects on a person’s skin, from wrinkles and sags to increased risk of certain skin conditions, such as skin cancer. As people age, their skin begins to change due to environmental factors, genetic makeup, nutrition and other factors. This study is an attempt to understand some of the changes that happen in skin aging including changes in the general morphological and architectural arrangement, cellularity, epidermal thickening, and basement membrane changes and demonstration of melanocytes and the biochemical profile including serum malondialdehyde level and blood superoxide dismutase level.
Skin specimens were taken from the anterior abdominal wall of 30 human males at different ages, they were grouped into three age groups: Age group (A) (1-9) years, Age group (B) (12-30) years and Age group (C) (40) years and above. They were stained with: •Haematoxylin and Eosin (H&E): used with paraffin sections to demonstrate the morphological changes in the skin with age. • Nuclear differentiation stain (NDS): used with semithin sections to demonstrate different types of cells nuclei in the skin. • Periodic Acid-Schiff Technique (PAS): used with paraffin sections to demonstrate the changes of basement membrane thickness with age. • S-100 protein to demonstrate immunohistochemistry labeled melanocytes changes with age.
Histometricale measurement of epidermal thickness using eyepiece graticule was performed on these groups, measurement of serum (MDA) and blood (SOD) levels for each age group. Age groups (A) and (B) were showed a uniform arrangement of cells in all stratums of the epidermis, the diminished thickness of the epidermis was a stricking feature in age group (C). Distinction between the five stratums of the epidermis was not easy yet it remained present in a uniform way, although they were diminished to some extent.
A significant difference between (age group A - B) and between the age group (C) was recorded, but no convincing difference in the epidermal thickness between age groups (A) and (B). The epithelial basement membrane thickness increased with age significantly with a (P value ≤ 0.001). We found no previous study that had dealt with measurement of basement membrane thickness and its changing during aging. In demonstration of melanocytes using S-100, Melanocytes cells tend to be situated at the tips of rete peges, their number was generally low and didn't vary a lot between age groups (A) and (B). There was yet a marked decline in the number of melanocytes in age group(C). The results of present study were showed that the levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were changing with age advance. In this study, the results also showed a difference between the levels of serum malondialdehyde (MDA) and blood superoxide dismutase (SOD) in the three age groups, malondialdehyde (MDA) a econdary product of lipid peroxidation, with a significant (P<0.05) showed an increase with age, while superoxide dismutase (SOD) the first defense line against superoxide radical, with a significant (P<0.05) was decreasing with age. Except for age group (A), due to the immature superoxide dismutase (SOD) system at this age.
This study conclude that aging as a process have a marked influences on skin morphology, thickness, cellularity and basement membrane thickness. Biochemical changes were another important aspect of skin aging.