Tatsuo Akimoto

Salivary gland scintigraphy in gastro-esophageal reflux disease

Abstract.Gastro-esophageal reflux disease (GERD) is associated with a decreased salivary flow as well as gastric acid production. This study therefore aimed to investigate functional disorders of salivary glands in patients with GERD.Methods:Thirty-one consecutive patients with GERD underwent salivary gland scintigraphy.Results:If the results defined the optimal cutoff point for determining the decreased salivary secretion as 51 % in parotid glands and 36 % in submandibular glands, a decreased salivary secretion of right parotid gland, left parotid gland, right submandibular gland, and left submandibular gland was found in 39 %, 32 %, 36 %, and 58 %, respectively. Overall, salivary function disorder of at least one major salivary gland was found in 24 patients (78 %) with GERD. There was no difference in the incidence of impaired salivary function between GERD patients with and without erosive esophagitis. Salivary gland function was more frequently diminished than expected in GERD. We concluded that the presence of impaired salivary gland function was considered to be one of risk factors for developing GERD symptoms.

Changes in renal vessels following the long-term administration of an angiotensin II receptor blocker in Zucker fatty rats

Introduction: The nephro-protective effects of angiotensin II receptor blockers (ARBs) are widely known; however, there are few reports of long-term effects focusing on the renal vessels. We studied afferent arteriolar changes induced by the long-term administration of an ARB. Materials and Methods: Thirty-two 6-week-old male Zucker fatty rats (ZFRs) were divided into following four groups (n = 8 in each): ZFR Group and ZFR+High Group fed a standard or high-salt diet, respectively; ZFR+ARB Group and ZFR+High+ARB Group fed a standard or high-salt diet with ARB (Olmesartan, 5 mg/kg/day), respectively. Blood pressure, proteinuria, morphological examinations and glomerular haemodynamics in vivo were studied. Results: Marked proliferative changes in the afferent arteriolar smooth muscle cells (SMCs) were frequently observed in the two groups given ARBs; in the ZFR+ARB group (77.3±10.3%) compared with the two groups without ARB (1.7%, p < 0.005; 1.2%, p < 0.0005) and 37.4±15.6% in the ZFR+High+ARB group. Proteinuria markedly decreased in the groups treated with ARBs, but the glomerular erythrocyte velocities showed no differences. Conclusions: Our findings indicate that long-term ARB administration induced unusual proliferative changes in SMCs of afferent arterioles of ZFRs. These changes could narrow arteriolar lumens and reduce intraglomerular pressure, but they could cause also irreversible damage to the arterioles.

Proliferative changes of renal arteriolar walls induced by administration of angiotensin II receptor blocker are frequent in juvenile rats

Introduction: Our previous study of angiotensin II receptor blocker (ARB) administration in rats induced unusual proliferative changes of smooth muscle cells in renal arteriolar walls. The present study examined if the incidence of the changes depended on the rats’ age, and how long it would take to find changes. Materials and methods: Six-week-old (juvenile spontaneous hypertensive rats (SHRs)+ARB group, n=15) and 20-week-old (adult SHRs+ARB group, n=10) male SHRs were fed a standard diet (0.4% NaCl) containing valsartan (10 mg/kg/day; Novartis Co.). Fifteen age-matched SHRs were studied as controls. After 4, 8, and 12 weeks, the rat kidneys were examined under light and electron microscopes and through immunohistochemical studies. Results: Extremely concentric proliferative changes in afferent arteriolar walls were frequently observed in the juvenile SHR+ARB group compared to the adult SHR+ARB group (48.7±6.8% vs 19.3±6.9%; p=0.0307) at the 12th week. Increased renin expression and arteriolar changes were found from the 4th week in the juvenile SHR+ARB group. Conclusion: This study indicates that ARB administration induces unusual proliferative changes and a marked renin-producing cell increase in afferent arterioles more frequently in juveniles than adult rats. It is suggested that the treatment of ARB in juveniles might have a higher risk of changes in renal afferent arterioles.

Changes in renal vessels associated with long-term administration of angiotensin converting enzyme inhibitor in Zucker fatty rats

Background Recently, we showed that long-term angiotensin receptor blocker (ARB) administration induced unusual proliferative changes in smooth muscle cells (SMCs) of afferent arterioles of the kidneys of Zucker fatty rats (ZFRs). In this study, we investigated renal afferent arteriolar changes induced by the long-term administration of an angiotensin converting enzyme inhibitor (ACEI) in ZFRs. Materials and Methods Fourteen 6-week-old male ZFRs were divided into two groups (n=14): the ZFR+ACEI group (n=6) was fed a standard diet containing ACEI (Enalapril, 2 mg/kg/day), and the ZFR control group (n=8) for 12 weeks. Blood pressure and proteinuria were examined and morphological studies on kidneys were performed. Results Remarkable proliferative changes in the afferent arteriolar SMCs were frequently observed in the group given ACEI; (66.1 ± 12.9%) compared with the control group (1.77 ± 1.56%, P<0.001). Conclusions It was indicated that long-term ACEI administration induced unusual proliferative changes in SMCs in afferent arterioles of ZFRs. These changes could reduce intraglomerular pressure by narrowing the lumens of afferent arterioles, but they could cause irreversible damage to the arterioles.

DIFFUSE WHITE DEPOSITS OF THE DUODENUM MAY SUGGEST DELAYED GLUCOSE ABSORPTION

Background:  The aim of the present study was to evaluate the relationship between white deposits observed in the duodenum and malabsorption of nutrients.