Susumu Matsuda

Up-regulation of Akt and eNOS induces vascular smooth muscle cell differentiation in hypertension in vivo.

Recent studies have shown that angiotensin II type 1 (AT1) receptor-mediated Akt activation induces vascular smooth muscle cell (VSMC) dedifferentiation in vitro. However, the critical signal transductions affecting the VSMC phenotype remain unclear in vivo. We examined whether signal transduction through AT1 receptor-mediated reactive oxygen species (ROS) could regulate the VSMC phenotype in stroke-prone spontaneously hypertensive rats (SHRSPs). Male SHRSPs were randomized and treated for 6 weeks with a vehicle, an ACE inhibitor cilazapril, or an AT1 receptor antagonist E4177. The 2 drugs showed equipotent effects on the blood pressure, aortic morphology, and collagen deposition. Both drugs also significantly reduced aortic NAD(P)H oxidase activity and p38MAPK and ERK expression, whereas p-Akt, eNOS, and SM2 were significantly increased in SHRSP aortas. Furthermore, E4177 was more effective than cilazapril at inducing VSMC differentiation by reducing NAD(P)H oxidase activity, and up-regulating p-Akt, eNOS, and SM2. Thus, an ACE inhibitor and an AT1 receptor antagonist inhibited VSMC dedifferentiation through inhibition of NAD(P)H oxidase activity and up-regulation of eNOS and Akt in SHRSP aortas, suggesting that in contrast to the in vitro experiments, AT1 receptor-mediated NAD(P)H oxidase-generated ROS, eNOS, and Akt might be crucial determinants for the VSMC phenotype in hypertension in vivo.

Reconstructive vascular surgery for radical resection of malignant duodenal tumor

Abstract A case of huge reticulum cell sarcoma of the third part of the duodenum, involving the superior mesenteric arterial trunk, is reported. For curative resection of the tumor, resection of the involved superior mesenteric arterial segment and arterial reconstruction were necessary. The main branch of the superior mesenteric artery was anastomosed end to end to the right internal iliac artery with the insertion of an autogenous vein graft; after this about 120 cm. of the terminal ileum remained viable. The postoperative angiogram demonstrated good flow through the vascular anastomosis. A postoperative gastrointestinal series revealed about 120 cm. of the small bowel with a normal diameter and mucosal pattern. This report attests to the feasibility of this type of surgery for malignant abdominal tumors.