In this symposium, author's opinion about the balneotherapeutic practice of the digestive disorders was expressed.
1) At the beginning of this speech, author's fundermental studies on this theme hitherto were shortly summerized as premise.
2) According to these conclusions, it is very neccesary for the indication of the balneotherapy of digestive disorders to classify thermal springs (not only thermal water, but also hot spring place included) into two groups: one is so-called medicinal or therapeutic spring (“Heilquelle”) and the other is “recreation hot spring” (“Erhohmgsquelle”) (that is hot spring for maintenance and improvement of health).
3) The former is the hot spring intend to medical treatment of digestive diseases and the latter is that intend to health preservation, health promotion, normalising or adjusting the digestive dysfunction.
4) From this point of view, the author mentioned my own opinion concretely and practically about the indication of both “Heilquelle” and “Evholungsquelle” for the digestive diseases and disorders.

It has been widely recognized that the drinking of strongly acid hot spring water often causes gastrointestinal symptoms. However, the research in this subject has been distinctly sporadic.
Fundamental and clinical experiments were undertaken to ascertain the effect of the drinking of Tamagawa Spa on the gastrointestinal mucosa. The property of Tamagawa Spa, Akita prefecture, is acid vitriol spring whose pH value is 1.2, and it contains a large amount of hydrochloric acid and hydrogen sulfide.
1. Studies in Man
The changes of gastric mucosa in 36 subjects after the drinking of hot spring water were observed by gastrocamera or gastrofiberscope.
Varying degrees of hyperaemia were found in all subjects administered non-diluted hot spring water, whereas these change were markedly reduced in subjects administered two times and over diluted hot spring water.
No instances of erosion or ulceration were seen in any of the subjects.
2. Experiments in Animals
Twenty three healthy rabbits, orally administered non-diluted or diluted hot spring water for seven days were autopsied.
The changes of gastric mucosa were similar to those in man, and no significant influence on the jejunal mucosa was seen. Microscopically the affected mucosa revealed degeneration of the epithelial cells of gastric gland and edema of the submucosa.
Based on the critical review of former studies, several important factors were suggested to explain the occurrence of gastric impairment after the drinking of Tamagawa Spa water.

Between 1968 and 1992, a total of 174, 632 people were discharged from our hospital, of which 6, 265, or 3.6%, were dead. During the 25-year period, the number of discharges increased by 1.5 times, while the number of deaths by 2.6 times. We looked into, physicians' reports to find out the age, sex and the cause of death of the patients. Age-wise death rates have been on the decline among the younger patients and on the increase among the eledery patients of 60 years and above, during the period under review. Malignant neoplasms accounted for 62.2% of the causes of death. Especially worthy of note was the fact that deaths from lung cancer have increased at an alarmingly fast rate.

We tested the hypothesis that a force reduction in soleus muscles from hyperthyroid rats would be associated with oxidative modification of myofibrillar proteins. Daily injection of thyroid hormone [3, 5, 3’-triiodo-_L-thyronine (T₃)] for 21 days depressed isometric forces in whole soleus muscle across a range of stimulus frequencies (1, 10, 20, 40, 75 and 100 Hz) (P<0.05). In fiber bundles, hyperthyroidism also led to pronounced reductions (P<0.05) in both K⁺- and 4-chloro-m-cresol-induced contracture forces. The degrees of the reductions were similar between these two contractures. These reductions in force production were accompanied by a remarkable increment (103% ; P<0.05) in carbonyl groups comprised in myofibrillar proteins. In additional experiments, we have also tested the efficacy of carvedilol, a non-selective β₁-β₂-blocker that possesses anti-oxidative properties. Treatment with carvedilol prevented T₃-induced oxidation of myofibrillar proteins. However, carvedilol did not improve the hyperthyroid-induced reductions in force production. These data suggest that oxidative modification of myofibrillar proteins may not account for the reductions in force production of hyperthyroid rat soleus muscle.

This paper deals with general survey of hot spring curative treatment at Higashine Spa, Yamagata Prefecture, and the effect of this spa on the capillary resistance and the variation in the blood pressure.
The results of the medical survey are summarized as follows:
1) Higashine Spa consists of saline weak common salt springs, in each of which chemical components are almost the same.
2) The visitors to this spa are inhabitants of Yamagata Prefecture, farmers being the largest in number.
3) Most of them (78%) are old men and women over 50 years of age, and the number of women are four times that of men.
4) The examination of spa visitors reveals that hypertension stands at the top. However, in most cases, the chief complaints are of rheumatic disorders in natwe and hypertension is found at the time of medical examination.
5) Those who bathe five times a day are the largest in number.
6) Those who noticed the bathing reaction are small in number. The bathing reaction may be considered as a serious thermal crisis.
7) Bathing in this hot spring increases the capillary resistance and lowers the blood pressure.
Accordingly, bathing in this spa, under a proper guidance, may be effective in the treatment of hypertension. For balneal treatment of hypertension, physicians' directions as to how and when patiens should bathe, will be necessary: unplanned bathing cannot be approved of.