RESUMEN
Objective To study the effects of angiotensin Ⅱ(AngⅡ) on cardiac cAMP accumulative levels induced by isoprenalin(Iso) and AngⅡ on positive inotropic response induced by Iso stimulation ?-adrenoceptor (?-AR) in 3.5- and 12.0- months-old rats. Methods Radioimmunoassay and functional experiment of isolated left atrias were applied to measure the levels of cAMP and cGMP and the positive inotropic response in the hearts. Results Iso increased cAMP accumulation in 3.5-month-old rats〔(1 027?169)pmol/mg vs (1 400?267)pmol/mg,P
RESUMEN
Objective To find out the protective effects of angiotensin Ⅱ recepter antagonist(ATRA)of Losartan and the calcium channel blockade(CCB)of Amlodipine on the SHR rat kidney. Methods The rats were divided into 3 groups,one group received Losartan(30 mg?kg -1 ?d -1 ),another group Amlodipine(10 mg?kg -1 ?d -1 ),for 3 months, while the control group received only water. All rats were tested for blood pressure(BP),proteinuria(UP),angiotensin(ATⅡ),endothelin(ET),kaluretic peptide(KP),atrial natriuretic peptide(ANP),aldosterone(Ald)and the pathological renal lesions,the expression of collagen Ⅳ(CoⅣ)and laminin(LM)were observed in SHR and Wistar kyoto(WKY)rats before and after the treatment. Results Losartan and Amlodipine not only significantly lowered the BP,24 h UP and pathological renal injuries,modulated the relaxation contraction of vascular substances in blood,but also significantly lessened the expression of CoⅣ and LM and ameliorated the glomerular sclerosis in SHR. Conclusions The modulation of Losartan and Amlodipine on the ratio of relaxative and contractive vascular substances in blood and on the extracellular matrix(ECM) metabolism through the ATⅡ, Ald and ET pathways may be one of the mechanism of ATRA and CCB on ameliorating the glomerular sclerosis.