Effects of the antihypertensive drug efonidipine hydrochloride on albuminuria and renal histopathology in young spontaneously hypertensive rats with diabetes

Effects of efonidipine on platelet and monocyte activation markers in hypertensive patients with and without type 2 diabetes mellitus

We compared the levels of microparticles, platelet activation markers, soluble cell adhesion molecules, and soluble selectins between hypertensive patients with and without type 2 diabetes and control subjects. Binding of anti-glycoprotein IIb/IIIa and anti-glycoprotein Ib monoclonal antibodies to platelets did not differ significantly between the hypertensive patients and controls, but platelet expression of activation markers (CD62P, CD63, PAC-1, and annexin V) was higher in the hypertensive patients. Platelet-derived microparticle (PDMP) and monocyte-derived microparticle (MDMP) levels were significantly higher in the hypertensive patients than in the controls. Soluble ICAM-1, VCAM-1, P-selectin, and E-selectin levels were also higher in the hypertensive patients, and they were significantly higher in the hypertensive patients with diabetes. After treatment with efonidipine, the levels of PDMPs, CD62P-, CD63-, PAC-1-, and annexin V-positive platelets, sICAM-1, sVCAM-1, sP-selectin, and sE-selectin all decreased significantly. The MDMP levels decreased, and the decrease was significant in the hypertensive patients with diabetes. These findings suggest that administration of efonidipine to hypertension patients with diabetes may prevent the development of cardiovascular complications caused by cell adhesion molecules or activated platelets and monocytes.

Efonidipine hydrochloride: a dual blocker of L- and T-type ca(2+) channels

T-type Ca(2+) channels have properties different from those of the L-type and are involved in cardiac pacemaking and regulation of blood flow, but not in myocardial contraction. Efonidipine is an antihypertensive and antianginal drug with dihydropyridine structure that was recently found to block both L- and T-type Ca(2+) channels. In isolated myocardial and vascular preparations, efonidipine has potent negative chronotropic and vasodilator effects but only a weak negative inotropic effect. In experimental animals and patients, reduction of blood pressure by the drug was accompanied by no or minimum reflex tachycardia leading to improvement of myocardial oxygen balance and maintenance of cardiac output. Efonidipine increased glomerular filtration rate without increasing intraglomerular pressure. By relaxing both the afferent and efferent arterioles, efonidipine markedly reduced proteinuria. Thus, efonidipine, an L- and T-type dual Ca(2+) channel blocker, appears to have an ideal profile as an antihypertensive and antianginal drug with organ-protective effects in the heart and kidney.

Effects of the antihypertensive drug nifedipine on albuminuria and renal histopathology in young spontaneously hypertensive rats with diabetes

We investigated the renal protective effect of nifedipine (2-nitrophenyl derivative BAY a 1040) in streptozotocin (STZ)-induced spontaneously hypertensive rats (SHRs, 8 weeks of age). Diabetic SHRs were treated with 40 mg/kg/day of nifedipine or efonidipine as controls for 16 weeks. Dosage of nifedipine or efonidipine was chosen after preliminary studies demonstrated that it showed moderate antihypertensive action (more than a 20% decrease in systemic blood pressure after treatment). In the diabetic SHR, the excretion of urinary albumin was increased and reached 4.41 +/- 0.08 mg/day at 24 weeks. The levels of urinary albumin in the diabetic SHR after treatment with nifedipine were significantly less than those in the diabetic SHR at 24 weeks (p < 0.01). Levels of the ratio of creatinine clearance to body weight were significantly decreased in the diabetic SHR after treatment with nifedipine. In light microscopy, the ratio of glomerular tufts to Bowman's areas was significantly decreased compared with those in the diabetic SHRs (p < 0.05). These findings suggest that nifedipine inhibits the development of albuminuria and glomerular enlargement in STZ-induced diabetic SHRs. There was no significant difference in the changes in antihypertensive or antialbuminuric effects between nifedipine and efonidipine. Thus, nifedipine, as well as efonidipine, may become a useful antihypertensive drug with a renal protective effect.