Effects of prenatal methylmercury exposure on urinary proximal tubular enzyme excretion in neonatal rats.
The basal developmental pattern of excretion of 3 proximal tubular enzymes was determined in 8-h urinary specimens from neonatal rats. Gammaglutamyltransferase (GGT), alkaline phosphatase (ALP), and N-acetyl-beta-glucosaminidase (NAG) activities were measured at 3, 6, 9 and 12 days after birth. Subsequently, methylmercury chloride (CH3HgCl), known to induce foetotoxic changes in the proximal tubule was administered on days 8, 10 and 12 of gestation at 3 or 6 mg/kg and its effects on the enzyme activities were examined. Dose-related increases in the 3 enzyme activities occurred at dose levels that produced no maternal or postnatal toxicity, nor overt morphological malformation of the kidney. The peak of enzyme activities averaged about 200% and 130% of the control values for GGT, ALP, and NAG respectively, and occurred on days 3 and 6 in the treated groups. Urinary enzyme activities returned to the control levels from days 6 to 12. Our data point to the possibility of detecting CH3HgCl-induced prenatal effect on the kidney by measuring the 8-h urinary excretion of enzymes by rats in the early postnatal period.
Saillenfait
A M
AM
Institut National de Recherche et de Sécurité, INRS, Vandoeuvre, France.
Brondeau
M T
MT
Zissu
D
D
de Ceaurriz
J
J
D000118:Acetylglucosaminidase / Q000652:urine; D000367:Age Factors; D000469:Alkaline Phosphatase / Q000652:urine; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008767:Methylmercury Compounds / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D005723:gamma-Glutamyltransferase / Q000652:urine
D008767:Methylmercury Compounds; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase; D000118:Acetylglucosaminidase