The role of renal proximal tubule transport in the regulation of blood pressure

The electrogenic sodium/bicarbonate cotransporter 1 (NBCe1) on the basolateral side of the renal proximal tubule plays a pivotal role in systemic acid-base homeostasis. Mutations in the gene encoding NBCe1 cause severe proximal renal tubular acidosis accompanied by other extrarenal symptoms. The proximal tubule reabsorbs most of the sodium filtered in the glomerulus, contributing to the regulation of plasma volume and blood pressure. NBCe1 and other sodium transporters in the proximal tubule are regulated by hormones, such as angiotensin II and insulin. Angiotensin II is probably the most important stimulator of sodium reabsorption. Proximal tubule AT(1A) receptor is crucial for the systemic pressor effect of angiotensin II. In rodents and rabbits, the effect on proximal tubule NBCe1 is biphasic; at low concentration, angiotensin II stimulates NBCe1 via PKC/cAMP/ERK, whereas at high concentration, it inhibits NBCe1 via NO/cGMP/cGKII. In contrast, in human proximal tubule, angiotensin II has a dose-dependent monophasic stimulatory effect via NO/cGMP/ERK. Insulin stimulates the proximal tubule sodium transport, which is IRS2-dependent. We found that in insulin resistance and overt diabetic nephropathy, stimulatory effect of insulin on proximal tubule transport was preserved. Our results suggest that the preserved stimulation of the proximal tubule enhances sodium reabsorption, contributing to the pathogenesis of hypertension with metabolic syndrome. We describe recent findings regarding the role of proximal tubule transport in the regulation of blood pressure, focusing on the effects of angiotensin II and insulin.

Two Elderly Cases of Copious Sweating Successfully Treated with "Furidashi" Extract of Astragali Radix / 日本東洋医学雑誌

We report on two elderly patients in the extended care unit who were successfully treated with “Furidashi” extract (an extraction method of dipping in hot water) of Astragali Radix, for copious sweat. Case 1 was a 65-year-old male hospitalized for rehabilitation after cerebral hemorrhage. He needed a change of clothes three or four times a day because of copious sweat. After administration of Hochu-ekki-to and “Furidashi” extract of Astragali Radix, his sweat decreased. Case 2 was a 66-year-old female hospitalized for rehabilitation after cerebral contusion. She was dripping-wet with perspiration, and had itchy eczema and skin erosions on her trunk. After administration of the “Furidashi” extract of Astragali Radix, her sweat decreased and the erosions were cured. This strongly suggests that the “Furidashi” extract of Astragali Radix provides a convenient and inexpensive treatment against copious sweat accompanied by skin disorder in the elderly.

Successful Kampo Treatment for Three Patients with Hypogeusia / 日本東洋医学雑誌

Most patients with taste disorders are usually treated with zinc, but there still remain many untreatable patients, including non-responders and those of advanced age. In this study, we report on three patients with hypogeusia who showed improvement after the administration of Kampo medicine. A 49-year-old female diagnosed with hypogeusia and hyposensation of the oral cavity responded to Oren-gedoku-to. A 43-year-old male diagnosed as having schizophrenia and hypogeusia and a 76-year-old female with idiopathic hypogeusia responded to Saiko-ka-ryukotsu-borei-to. Kampo medicines are considered to normalize zinc-related neuro-transmissions originating in the vallate taste buds. Furthermore, the curative effect of Oren-gedoku-to on inflammation-injured oral cavity membranes, and the psychotropic effect of Saiko-ka-ryukotsu-borei-to on improving hypogeusia, were shown in our patients. It should be noted that the recent increase in aged patients complaining of taste disorders might be related to aging-associated depression. Saiko-ka-ryukotsu-borei-to or related Kampo formulations are considered to have wide applications for depressed or aged patients with hypogeusia.

Three Case Reports of Muscle Weakness Successfully Treated with Isho-ho / 日本東洋医学雑誌

Isho-ho was used to successfully treat three cases of muscular weakness. The first case was a 59-year-old woman. In May of 1993, she began to suffer from a feeling of general lethargy. The condition was diagnosed as multiple myositis, and prednisolone was administered. However, since she still experienced loss of strength in the lower limbs, she was introduced to the authors' department for treatment in August of 1994. Administration of Isho-ho improved the loss of strength in the lower limbs and increased her grip strength.<br>The second case was a 42-year-old woman who complained of unusual sensations in the tips of her fingers and toes starting in mid-September, 1994. In November of the same year, she began to experience a loss of strength in the limbs. In February of 1995, the condition was diagnosed as chronic inflammatory demyelinatory multiple neuropathy by the same department, and large doses of steroids were administered. Although this treatment delayed the loss of strength in the lower back and legs, actual improvement in the condition did not occur until Isho-ho was given.<br>The third case involved a 63-year-old man who began to experience a loss of strength in the lower limbs in 1984. In 1988, the loss of strength became pronounced. In June of the same year, he sought treatment at the authors' department, and the condition was diagnosed as bulbar myelinic muscular atrophy. In October of 1993, he was unable to get out of bed unassisted, and was admitted to the authors' department. He was given Isho-ho, and reported a decrease in the feeling of a loss of strength in the lower limbs, and a disappearance of greater pectoral muscle spasms. These results suggest that Isho-ho is not only effective for loss of strength in the lower limbs, but may also be efficacious for loss of strength, numbness and muscle spasms in the upper limbs.