Postnatal development of renal function in piglets: glomerular filtration rate, clearance of PAH and PAH extraction

Area of Science:

• Nephrology
• Pediatric Physiology
• Animal Science

Background:

• Renal function development in neonatal animals is crucial for understanding physiological maturation.
• Piglets serve as a valuable model for studying human infant kidney development.
• Limited data exists on the precise timeline of renal function maturation in piglets.

Purpose of the Study:

• To quantify the development of glomerular filtration rate (GFR) and p-aminohippuric acid clearance (CPAH) in piglets from birth to adulthood.
• To assess the maturation of renal p-aminohippuric acid extraction (EPAH) during early life.
• To compare the rate of renal development in piglets to other animal models.

Main Methods:

• Measured GFR (inulin clearance) and CPAH in 32 unanaesthetized piglets (1-62 days old).
• Estimated renal PAH extraction (EPAH) in 12 anaesthetized piglets (1-79 days old).
• Analyzed changes in renal function parameters relative to age and kidney weight.

Main Results:

• GFR increased from 0.27 to 0.59 ml/min/g kidney and CPAH from 1.02 to 1.72 ml/min/g kidney during the study period.
• Adult GFR and CPAH values were attained by 8 weeks of age.
• EPAH increased from 0.75 at birth to 0.86 by 3 weeks of age, reaching adult levels.

Conclusions:

• Piglets exhibit a clear postnatal increase in key renal functions, including GFR, CPAH, and EPAH.
• Renal function maturation in piglets occurs progressively, with adult values achieved by 8 weeks.
• The developmental trajectory of renal function in piglets is less pronounced compared to some other species.