A comparative study of renal and hepatic function in Sprague-Dawley rats following systemic injection of purified carrageenans (kappa, lambda and iota).

Renal and hepatic function was investigated in groups of 7 rats for 14 days after a single i.p. injection of 125 mg/kg purified kappa (kappa), lambda (lambda) or iota (iota) carrageenan. Kappa carrageenan was clearly nephrotoxic, as evidenced by a progressive, marked increase in serum creatinine and urea levels and in urinary N-acetyl-beta-D-glucosaminidase (NAG) activity. It also caused significant elevation in serum aspartate aminotransferase (AAT) activity from Day 2 to Day 7, and a progressive decrease in circulating albumin concentrations. Lambda carrageenan had no significant effect on serum creatinine or urea levels and caused only a transient increase in urinary NAG which was maximal on Day 2. Serum AAT levels were also significantly raised on Day 2. Iota carrageenan injection resulted in the deaths of 2/7 animals. Significant increases in serum creatinine levels were observed on Day 4: in 2 rats these increase were very pronounced as were those in urea levels, but no significant alterations in serum urea or urinary NAG levels were observed. No significant elevation in serum AAT was found, except for minor changes on Days 7 and 14. Whereas lambda carrageenan decreased serum albumin throughout the 14-day course of the experiment, albumin levels in lambda carrageenan-injected rats, whilst depressed during the first week, returned to normal by Day 14.