Influence of an inhibitor of monoaminooxidase (nialamide) on the serum levels, urinary excretion and plasma clearance of urea, uric acid and creatinine in adult and growing rats.

Serum levels, urinary excretion and plasma clearance of urea, uric acid and creatinine were studied in adult (230 g) and growing (75 g) rats under the influence of nialamide (an IMAO) administered in daily doses of 20 mg/100 g diet during 15 or 30 days in adults and 10 mg/100 g diet during 15 days in growing rats. A pair feeding design was used in both ages. Serum levels of urea rose in adult rats fed nialamide for 30 days while urinary excretion decreased. No change in serum levels were noted in growing rats although urinary excretion showed a net increase. Serum uric acid levels were increased in adult female rats given nialamide for 30 days, while urinary excretion fell in both sexes. Growing rats showed a drop in urinary excretion of uric acid. Serum creatinine levels were unchanged in adult and growing rats after treatment with nialamide, although a marked increase was recorded in urinary excretion in both groups.