Sexually dimorphic proteinuria in Wistar rats: Relevance to clinical models

The study investigated the relationship between physiological proteinuria and the histomorphometry of the renal corpuscles in apparently healthy Wistar rats of both sexes, belonging to the same age group. This was with a view to appraise any possible connection between potential expression of sexual dimorphism and the histomorphometry of some integral parts of the glomerular filtration barrier. Twenty Wistar rats of both sexes between ages 9 and 10 weeks were used for this study. This comprised 10 male and 10 female rats weighing 110–200 g which were housed in separate metabolic cages for the collection of urine samples.They were sacrificed 24 h and 7 days after 2 weeks of acclimatization, respectively. The rats were fasted for 24 h during the collection of urine samples. The results showed 74.75% significantly higher urine total protein (p < 0.0001), 187.29% significantly higher mg protein/100 g body weight (p < 0.0001), 32.34% significantly higher Bowman's capsular thickness (p < 0.0001), 30.64% significantly higher glomerular thickness (p = 0.0002), 59.47% significantly higher Bowman’s capsular space (p = 0.003), 5.30% insignificantly lower creatinine clearance (p = 0.24) and 28.05% significantly higher level of urine protein to creatinine ratio (p < 0.0001) in the male when compared with their female counterpart. In conclusion, Wistar rats express sexually dimorphic proteinuria which is structural in origin.