A novel angiotensin II-receptor antagonist, 606A, induces regression of cardiac hypertrophy, augments endothelium-dependent relaxation and improves renal function in stroke-prone spontaneously hypertensive rats.

It is well-known that cardiac hypertrophy and arterial and renal dysfunction are serious complications of hypertension. Therefore, we investigated the chronic effects of 606A (2-propyl-3-[2'(1H-tetrazole-5-yl)biphenyl-4-yl]methyl-5-acetyl-4,5,6,7- tetrahydro imidazo [4,5-c]pyridine-4-carboxylic acid disodium salt), a novel AT1-receptor antagonist, on these complications of hypertension in stroke-prone spontaneously hypertensive rats (SHRSP) using Wistar Kyoto rats (WKY) as the control. After 8 weeks treatment from 16 weeks of age with 606A by a subcutaneously implanted osmotic pump, cardiac function, cardiac weight, acetylcholine-induced endothelium-dependent relaxation in the isolated aorta and renal function were estimated. Furthermore, wall thickness of the left ventricle was studied morphologically. We found that 606A (0.3 mg, 1 mg and 3 mg/head/day) dose-dependently lowered blood pressure without any effects on heart rate in SHRSP. Long-term treatments with 606A significantly reduced cardiac weight, left ventricular wall thickness and left ventricular end diastolic pressure, whereas it did not affect cardiac contractility. Endothelium-dependent relaxation of the aorta was recovered, and total protein excretion as well as total protein excretion/creatinine excretion ratio was reduced to the level of WKY by the treatment. These results suggest that 606A not only has a hypotensive effect but also protects cardiac, renal and vascular tissues from complications of hypertension. Thus, 606A could be an useful drug for treatment of hypertension.

[A case of successful surgical treatment of rectal cancer complicated by acute myelomonocytic leukemia].

A 47-year-old man, who had been diagnosed as having acute myelomonocytic leukemia (AMMOL) and had been treated with combination chemotherapy, was admitted to our hospital because he had developed melena. He had been judged to be in complete remission and had shown no signs of recurrence for years, Daunorubicin, vincristine 6-Mercaptopurine and Cyclophosphamide had been administered for maintenance and intensification therapy. He was well until January 1986, when this melena began. A barium enema was given and he was diagnosed as having rectal cancer. Amputation of the rectum and a permanent abdominal colostomy was made safely, mainly because he had been in complete remission, and he recovered normally after the operation. In recent years, the survival of patients with malignancies has improved due to aggressive treatment even in cases of hematological neoplasms. However, the risk of secondary neoplasms in patients treated for cancer has increased. This case suggests that we have to be careful when prescribing treatment for cancer patients, since anti-tumor drugs may have cartinogenic effects.