It has been reported that urinary urate excretion was increased by the spa treatment of gout. While it is generally accepted that mineral water constituents are absorbed through balneotherapy, not only by oral intake but also percutaneausly.
Two modes of hypouricemic action may be considered in the spa treatment: one is the promotion of urinary urate excretion, and the other is the suppression of urate formation.
The influence upon the purine metabolism was studied using Ikaho (iron containing calcium sulphate spring), Kusatsu (H₂S containing acid alum vitriol spring), Atami (weak common salt spring), Itoh (simple thermal), Shimobe (simple thermal), Masutomi (radioactive spring), & Otari (alkaline spring) waters, and the following results were obtained.
(I) In vitro experiments, xanthine oxidase activity was suppressed by Kusatsu, but it was accelerated by Atami, Ikaho and Masutomi.
No effect was shown by Itoh, Shimobe and Otari.
Uricase activity was suppressed markedly by Kusatsu, slightly suppressed by Atami, Ikaho, and Otari, but was not influenced by Itho, Shimobe and Masutomi.
(II) Xanthine oxidase activity and uricolytic activity were examined in the liver of rats after bathing for 15 minutes at 40°C and/or after administration of allopurinol, uric acid and alcohol.
The xanthine oxidase activity was decreased by bathing in Kusatsu thermal water and/or administration of allopurinol, but it was enhanced by plain water bathing while it was not changed by Ikaho and Atami thermal water bathing.
The uricolytic activity was decreased by the loading of uric acid and the administration of ethyl alcohol, enhanced by plain water bathing, and not changed by the bathing in Kusatsu, Ikaho, and Atami thermal waters.
(III) The purine metabolism was investigated in human subjects by the determination of urate and oxypurine in plasma and urine after oral administration of the mineral waters for three successive days.
By drinking of Kusatsu thermal water plasma urate and oxypurine levels were lowered and urinary excretions were increased.
By drinking of Ikaho a minor elevation of plasma urate and oxypurine levels were observed, but no changes were found in urinary excretion of these purines.
By drinking of Atami thermal water the plasma urate levels were lowered, but no definite trend was found in the plasma oxypurine levels.
Urinary oxypurine excretion was increased but orate excretion remained unchanged.

The effects of a 50Hz magnetic field on experimentally-induced inflammation in rats were studied. Carrageenan edema was inhibited significantly by exposure to magnetic field for 3 hours. Adjuvant-induced arthritis in rats was also suppressed by the magnetic field.