Renin, endothelial NO synthase and endothelin gene expression in the 2kidney-1clip Goldblatt model of long-term renovascular hypertension

Hypertensive Cardiomyopathy with Congestive Heart Failure in an Infant with Unilateral Wilms Tumor: A Case Report

Wilms tumor (WT) is the most common malignant kidney tumor in children. High blood pressure is seen in up to 55% of children with WT. However, hypertensive cardiomyopathy with congestive heart failure due to WT is remarkably rare, with only several cases reported worldwide. In this report, a pediatric case of WT with hypertension causing hypertensive cardiomyopathy and congestive heart failure is presented. An 8-month-old male child with abdominal distension was seen by his primary physician. He was referred to our hospital for further examination and treatment. Abdominal contrast-enhanced computed tomography demonstrated a weakly enhancing, large abdominal mass, which was larger than 12 cm. Two-dimensional transthoracic echocardiography showed a diffuse hypokinetic left ventricle. The patient was diagnosed with cardiomyopathy caused by hypertension. Open surgical resection of the mass was successfully performed. His postoperative course was uncomplicated, and the patient was successfully discharged. The plasma renin activity was maintained at a high level even after left nephrectomy, suggesting that the right kidney was likely the source of renin secretion. Mechanical compression of the right renal blood vessels by a greatly enlarged left kidney can cause right renal ischemia, which activates renin excretion. Nephrectomy can be an effective treatment for a WT patient with hypertension causing hypertensive cardiomyopathy, and then cardiac function will be improved within several weeks. We recommend routine echocardiography surveillance in patients with WT. This report can help pediatric surgeons become more familiar with cardiomyopathy caused by WT.

Antihypertensive effects of fargesin in vitro and in vivo via attenuating oxidative stress and promoting nitric oxide release

Fargesin, a bioactive neolignan isolated from magnolia plants, is widely used in the treatment of managing rhinitis, inflammation, histamine, sinusitis, and headache. To provide more biological information about fargesin, we investigated the effects of fargesin on rat aortic rings and 2-kidney, 1-clip (2K1C) hypertensive rats. In vitro, fargesin caused concentration-dependent vasorelaxation in rat isolated aortic rings induced by KCl and norepinephrine. The effect was weakened by endothelium denudation and nitric oxide (NO) synthesis inhibition. In vivo, the evolution of systolic blood pressure (SBP) was followed by weekly measurements. Angiotensin II (Ang II) and endothelin (ET) levels, NO and nitric oxide synthase (NOS), and plasma and liver oxidative stress markers were determined at the end of the experimental period. After 5 weeks of fargesin treatment, we found that fargesin treatment reduced SBP, cardiac hypertrophy, and Ang II and ET levels of hypertensive rats. Increased NOS activity and NO level were observed in fargesin-treated rats. Normalisation of plasma MDA concentrations and improvement of the antioxidant defence system in plasma and liver accompanied the antihypertensive effect of fargesin. Taken together, these results provided substantial evidences that fargesin has antihypertensive effect in 2K1C hypertensive rats via inhibiting oxidative stress and promoting NO release.

Effect of Cydonia oblonga Mill. leaf extracts or captopril on blood pressure and related biomarkers in renal hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cydonia oblonga Mill. (COM) is used in traditional Uyghur medicine to treat or prevent cardiovascular disease. In a previous study COM leaf extracts were found to be active in renal hypertensive rats (RHR). The present study tests the dose-dependence of the effect of ethanol leaf extracts on hypertension and on biomarkers associated with blood pressure control, such as angiotensin-II (AII), plasma renin activity (PRA), apelin-12 (A), endothelin (ET) and nitric oxide (NO), compared to captopril.

METHODS

Two-kidney one-clip (2K1C) Goldblatt model rats were divided randomly into six groups: sham, model, captopril 25 mg/kg, COM leaf extract 80, 160 and 320 mg/kg (n=10 each). Drugs were administered orally daily for eight weeks. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured before treatment and every 2 weeks. Blood and kidney samples were collected after the last treatment to measure AII, PRA, A, ET and NO.

RESULTS

RHR had increased blood pressure, AII, A, PRA, ET and decreased NO. Treatment with captopril reduced blood pressure, AII, A, PRA, and ET, though not quite to normal values. COM leaf extracts significantly and dose-dependently reduced blood pressure, AII, A, RA and ET, whereas NO was increased. The highest dose of COM had the same effects as captopril.

CONCLUSION

The effects of COM extracts on blood pressure and biomarkers were dose-dependent and at the highest dose similar to those of captopril. This suggests an action of COM on the renin-angiotensin system, which could explain its antihypertensive effect.

Effect of Cydonia oblonga Mill. fruit and leaf extracts on blood pressure and blood rheology in renal hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Quince, Cydonia oblonga Mill. (COM), is used in traditional Uyghur medicine to treat or prevent cardiovascular diseases. Uyghur people have greater longevity and lower blood pressure than other central Asian populations. We therefore tested COM fruit and leaf extracts on blood pressure and rheology in renal hypertensive rats (RHR).

MATERIALS AND METHODS

Two-kidney, one-clip (2K1C) renal hypertensive rats were divided randomly into eleven groups: sham, model, and model treated with daily doses of 80 and 160mg/kg aqueous or ethanol extracts of COM fruit or leaves, or 25mg/kg captopril (n=10 per group), given orally once daily for 8 weeks. Blood pressure was measured before treatment and every 2 weeks thereafter. Blood rheology was tested after 8 weeks.

RESULTS

Model rats had higher blood pressure than sham 8 weeks after the procedure (systolic blood pressure 193±7 vs. 138±8mmHg, p<0.05). Those treated with captopril had decreased blood pressure within 2 weeks but that did not return to the level found in the sham group at 8 weeks (167±7, p<0.05 vs. model). With the COM extracts, the effect on blood pressure was notable after 4 weeks. At 8 weeks blood pressure was similar with captopril and with 160mg ethanol leaf extract (166±4, p<0.05 vs. model), the most effective of the extracts. Model rats had higher blood viscosity and lower erythrocyte deformability than sham. Captopril had little effect on blood rheology; whereas COM extracts reduced whole blood viscosity and improved erythrocyte deformability to levels approaching those found in sham.

CONCLUSIONS

COM extracts have antihypertensive activity in renal hypertensive rats. The additional effect on rheology, compared to captopril, may convey added interest. Further studies of these effects in man appear warranted.