Alterations in Kidney Structures Caused by Age Vary According to Sex and Dehydration Condition

Aging is a complex biological process, resulting in gradual and progressive decline in structure and function in many organ systems. Our objective is to determine if structural changes produced by aging vary with sex in a stressful situation such as dehydration. The expression of Slc12a3 mRNA in the renal cortex, alpha-smooth muscle actin (alpha-SMA), and fibronectin was evaluated in male and female rats, aged 3 and 18 months, submitted and not submitted to water deprivation (WD) for 48 h, respectively. When comparing ages, 18-month-old males showed a lower expression of Slc12a3 mRNA than 3-month-old males, and control and WD 18-month-old male and female rats exhibited a higher expression of alpha-SMA than the respective 3-month-old rats. Fibronectin was higher in both control and WD 18-month-old males than the respective 3-month-old males. In females, only the control 18-month-old rats showed higher fibronectin than the control 3-month-old rats. When we compared sex, control and WD 3-month-old female rats had a lower expression of Slc12a3 mRNA than the respective males. The WD 18-month-old male rats presented a higher expression of fibronectin and alpha-SMA than the WD 18-month-old female rats. When we compared hydric conditions, the WD 18-month-old males displayed a lower relative expression of Slc12a3 mRNA and higher alpha-SMA expression than the control 18-month-old males. Aging, sex, and dehydration lead to alterations in kidney structure.

Automated summary

Aging affects kidney structure, and the changes vary with sex in a stressful situation such as dehydration. Male rats at 18 months of age showed lower expression of Slc12a3 mRNA but higher expression of fibronectin and alpha-SMA compared to younger males. In females, only fibronectin expression was higher in the 18-month-old rats. Dehydration also influenced gene expression, with 3-month-old females showing lower Slc12a3 mRNA expression than males, and 18-month-old males showing higher fibronectin and alpha-SMA expression compared to females. Overall, aging, sex, and dehydration contribute to alterations in kidney structure.