Studies on urinary arylsulphatase activity in vitamin A deficient rats.

Urinary arylsulphatases (E.C.3.1.6.1) A and B were increased in male rats fasted for 24 hours. Excretion of non dialysable protein nitrogen decreased whereas creatinine excretion increased. On refeeding diet arylsulphatase A activity was restored to normal whereas arylsulphatase B was not normalised. A single oral supplementation of vitamin A acetate (20 000 IU) to rats fasted for 24 hours resulted in a significant reduction of both arylsulphatase A and B eventhough no further reduction of protein nitrogen excretion was evident. In vitamin A deficient male rats significant reduction in urinary excretion of both arylsulphatases A and B occured. In a smaller number of female rats depression of only arylsulphatase A was observed. This effect of vitamin A deficiency leading to reduced urinary arylsulphatase activity was evident even at the "weight plateau" stage when no reduction in food intake or growth had occurred. These results suggest a possible direct or indirect role for vitamin A on urinary excretion pattern of arylsulphatases presumably released from lysosomes of tissues.