Background: Estimation of β-galactosidase (βgal) activity in human cells and tissues indicate its possible use as a marker of senescence.
Objectives: This study was done to detect senescence-associated βgal (SA-βgal) activity in canine skin tissue by using its substrate 5-bromo-4-chloro-3-indolyl β-D-galactosidase (X-gal).
Materials and methods: Skin samples were collected through rapid necropsy process. The X-gal staining was done by altering different factors of the staining procedure like pH of the reagents and incubation time. Further, effect of tissue preservation procedure was also evaluated.
Results: Typical X-gal staining was detected in old dogs' skin samples and it was detectable both at pH 6 and pH 7.3. The cells present in the inner lining of the hair follicles and sebaceous glands are the major cells that have high SA-βgal activity. The X-gal staining intensity was more prominent in tissues preserved in liquid nitrogen at -196°C than in -80°C freezer. Prolonged incubation period increased the intensity of staining.
Conclusions: This study indicates possibility of X-gal staining in canine tissues and opens an avenue for further in-depth studies that might be useful for different research and clinical studies like determination of dog's approximate age.
Keywords: X-gal; canine; senescence; skin; β-galactosidase.