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Y Takihana

Publications and source records attributed to Y Takihana.

6 recordsLinked to original sources
PubMed2001

Inhibition of nitric oxide synthase induces intestinal mucosal damage and increases mortality in rats treated by FK506.

INTRODUCTION: Despite the beneficial immunosuppressive effects of FK506 during small intestine transplantation, FK506 appears to have direct toxic effects on the intestine. The mechanisms of FK506-induced intestinal damage is unclear, and whether nitric oxide (NO) is involved in the mechanism has not been well defined. This study was designed to evaluate the effects of NG-Nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase, on small intestinal damage in rats treated with FK506. MATERIALS AND METHODS: Wistar rats weighing 240-260 g, aged 11 weeks, were administered FK506 (5 mg/kg/day i.m) and/or L-NAME (5 mg/dl in drinking water) for 10 days. Body weight gain, diarrhoea and mortality were observed during experiment. At the end of experiment, the intestinal specimens were excised for histological evaluation. In addition, the effects of L-aginine treatment (1 g/dl in drinking water) were evaluated in this study. RESULTS: L-NAME administration time-dependently induced diarrhoea and high mortality in the rats treated with FK506. At the end of 10 days treatment, 7 of 12 rats (58.3%) suffered from diarrhoea and 5 of 12 rats (41.7%) died in the FK506 + L-NAME group (vs. FK506 group, p = 0.05). A significant loss of body weight was also found in the rats treated with FK506 + L-NAME (-52.2 +/- 28.8 g, in FK506 + L-NAME group vs. -14.3 +/- 8.7 g in FK506 group, p = 0.001). In parallel with the severe diarrhoea and high mortality, the loss of villi, hemorrhage and necrosis (grade 5 of pathological damage) was seen in the small intestinal mucosa of rats treated with FK506 + L-NAME. L-arginine treatment in part prevented diarrhoea, mortality and pathological damage of small intestinal mucosa induced by L-NAME. CONCLUSIONS: Inhibition of NOS induces intestinal mucosal damage and increases mortality in rats treated with FK506. L-arginine treatment can in part prevent the injury induced L-NAME. The present study suggests that NO, as an important protective factor, may be involved in the FK506-induced intestinal damage.

Administration, Oral↗
PubMed1994

[Renal functional reserve in obstructive nephropathy].

This study was designed to evaluate renal functional reserve (RFR) in obstructive nephropathy using amino acid loading and the effect of angiotensin converting enzyme (ACE) inhibitor on RFR. We divided 24 rabbits into 4 groups, consisting of a control, 6-hours-bilateral ureteral obstruction (BUO), 24-hour BUO and 24-hour BUO pretreated with ACE inhibitor. Following the ligation of the bilateral ureters at the vesicoureteral junction, a unilateral ureter was released after a 6-hour or 24-hour duration in the obstructive groups. We measured RFR and renal vascular resistance after releasing a unilateral ureter in BUO. The baseline GFR values in the 6-hour and 24-hour BUO groups were significantly lower than that in the control. RFR were 0.34 + 0.04 ml/min/kg (control), 0.10 + 0.03 (6-hour BUO), 0.01 + 0.03 (24-hour BUO) and 0.10 + 0.01 (ACE inhibitor), respectively. RFR in the 6-hour BUO group was well preserved compared with that in the 24-hour BUO group. Pretreatment with ACE inhibitor in the 24-hour BUO group enhanced RFR to the extent of 6-hour BUO. Our results demonstrated that angiotensin II plays an important role in decreased GFR with obstructive nephropathy. Moreover, the present data suggested that evaluation of RFR might play a key role in the recovery of the post-obstructive renal function.

Animals↗
PubMed1987

Ex vivo comparison of radiological and histological evaluation of early metastatic lesions of pelvic lymph nodes from carcinoma of the bladder or prostate.

To study the limitations of lymphangiography in the detection of early lymphatic spread of pelvic malignancies, we evaluated 587 lymph nodes from 23 patients with stages pN0 to 2 carcinoma of the bladder or prostate. Pelvic lymphadenectomy was performed 5 to 10 days after bipedal lymphangiography. Excised lymph nodes were separated one by one and an x-ray of each node was taken (lymphnodegram). The individual lymphnodegram was compared to the histological findings. Interpretations of lymphnodegrams from all 17 nodes with metastases were positive in 5, suspicious in 1, negative in 9 and radiolucent in 2. False negative judgments occurred chiefly because metastatic foci were microscopic. Two lymph nodes without metastasis were interpreted as positive for disease because of fat replacement of the nodes. These results indicated that lymphangiography is not suitable for the detection of early lymphatic metastases of carcinoma of the bladder or prostate.

Humans↗
PubMedDate not supplied

Gene and protein expression profiles of prostaglandin E2 receptor subtypes in the human corpus cavernosum.

Prostaglandin E1 leads to penile erection, mainly via prostaglandin E2 (EP) receptors. This study aimed to identify the expression profile of EP receptor genes in human corpus cavernosum. Using the quantitative real-time reverse transcription polymerase chain reaction, the mRNA levels of EP receptor subtypes were measured. In addition, expressions of EP receptor subtype proteins were determined by immunohistochemical method. Among the four subtypes, EP4 receptor mRNA expression was the highest, and EP2 receptor mRNA followed, whereas EP1 and EP3 receptor mRNAs were hardly observed. Expression level of EP4 receptor mRNA was significantly higher than that of EP2 receptor mRNA. Expression of both EP2 and EP4 receptor proteins were clearly detected in the cavernous smooth muscle. These results may suggest that EP4 receptor plays an important role among four EP receptor subtypes for relaxation of smooth muscle in the human corpus cavernosum.

Aged↗