In order to clarify why orthopedic complaints such as lumbago are ameliorated by hot-spring bathing, serum levels of sialic acid and fucose, which form glycoconjugates and are markers of connective tissue metabolism, were measured before and after each hot-spring bathing. No changes were observed in serum sialic acid for persons who took hot-spring bathing more than three times per day for 10 days. However, many of them showed a decreasing tendency in serum fucose level after bathing. Although it is not clear why this tendency occurs, it strongly suggests that hot-spring bathing influences on connective tissue metabolism.

Although it is well known that orthopedic complaints such as lumbago and shoulder pain can be reduced by hot spring bathing, the mechanism of such reduction is not yet fully known. Therefore, to clarify the mechanism, how the metabolism of glycosaminoglycans, which form connective tissue of articulations and cartilage, changes during hot spring bathing was investigated. Urine was sampled from those visitors at a hot spring who have orthopedic complaints such as lumbago but with no internal disease immediately before the session of hot spring bathing and at intervals of 1 week for a period of 5 week after starting hot spring bathing. The glycosaminoglycan fractions were separated from urine using the cetylpyridinium chloride precipitation and ethanol precipitation methods. Uronic acid contents were then estimated by the carbazole reaction method. The glycosaminoglycan levels in urine increased temporarily one week after starting hot spring bathing, then decreased to the level before starting bathing. The results of investigations using two-dimensional electrophoresis on cellulose acetate membranes revealed that chondroitin and chondroitin sulfate increased one week after beginning hot spring bathing. Because chondoritin is a progressive degradation product of chondroitin sulfate, the increase in chondroitin means that the metabolism of the chondroitin sulfate in the connective tissue was temporarily accelerated by hot spring bathing and was reflected as a reduction in complaints.

It is well known that gynecological complaints are ameliorated by hot spring bathing. We therefore investigated the changes in urinary mucin excretion before and after 14 days of daily hot spring bathing in order to clarify the relationship between hot spring bathing and complaint amelioration. Urine was collected from 28 female adults (64.3±7.0 years old) before and after the 14 days of hot spring bathing. Urinary mucins containing sialoglycopeptides and sulfated glycopeptides were separated from the urine using the ethanol and cetylpyridinium chloride precipitation methods, then indentified with two-dimensional electrophoresis on cellulose acetate membranes.
After the removal of glycosaminoglycan contamination by glycosaminoglycan-degrading enzymes, mucin amounts were determined by the phenol-sulfuric acid method. The results showed that the levels of both sialoglycopeptides and sulfated glycopeptides increased after 2 weeks of bathing. The level of urinary mucin, which is synthesized and excreted from the epithelial cells, increased as a result of hot-spring bathing. Therefore, it is highly likely that the amelioration of gynecological complaints of females is related to the chages in urinary mucin excretion brought about by hot spring bathing.