Drugs online research references








Acta Physiol Scand. 2000 Jan;168(1):47-51.
Interactions of the renin-angiotensin system and neuronal nitric oxide synthase in regulation of cyclooxygenase-2 in the macula densa.

Harris RC, Cheng H, Wang J, Zhang M, McKanna JA.

George M. O'Brien Kidney and Urologic Diseases Center and Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

Cyclooxygenase-2 (COX-2) expression in rat kidney is localized to the macula densa and the immediately proximal cTALH and increases after salt restriction. Either ACE inhibitors or AT1 receptor blockers increase COX-2 expression in both control and salt-restricted animals, suggesting that the RAS activation feedback inhibits renal cortical COX-2 expression. To determine whether increased COX-2 expression in response to ACE inhibition mediated increases in renin production, rats were treated with Captopril for 1 week with or without the specific COX-2 inhibitor, SC58236. Plasma renin activity increased significantly in the Captopril group. This increase was partially reversed by simultaneous treatment with SC58236. Kidney renin activity also increased in the Captopril group compared with control, which was also significantly inhibited by SC58236 treatment. Because of the localization of bNOS to MD and surrounding cTALH, the current study investigated the role of NO in the regulation of COX-2 expression. Rats were fed a normal diet, low salt diet or low salt diet combined with captopril and half of them were treated with the neuronal NOS inhibitor, 7-NI, and half with vehicle. After 7 days, mRNA was extracted and the microsome proteins purified from renal cortex. COX-2 mRNA expression was measured by Northern-blot and normalized with GAPDH. 7-NI treatment decreased COX-2 mRNA and immunoreactive COX-2 expression in each group. In summary, these studies indicate that COX-2 from macula densa/cTALH is a regulator of renin production and release. Angiotensin II may be a negative regulator of cTALH/macula densa COX-2 expression, and NO may mediate increased renal cortical COX-2 expression seen in volume depletion. These studies suggest important interactions between the NO and COX-2 systems in the regulation of arteriolar tone and the renin-angiotensin system by the macula densa.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10691779&dopt=Abstract




Circulation. 2000 Feb 29;101(8):844-6.
Maximally recommended doses of angiotensin-converting enzyme (ACE) inhibitors do not completely prevent ACE-mediated formation of angiotensin II in chronic heart failure.

Jorde UP, Ennezat PV, Lisker J, Suryadevara V, Infeld J, Cukon S, Hammer A, Sonnenblick EH, Le Jemtel TH.

Department of Medicine, Division of Cardiology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.

BACKGROUND: The added benefits of angiotensin II type I receptor (AT(1)) blockers (ARBs) to ACE inhibition suggests that recommended doses of ACE inhibitors provide only partial inhibition of ACE in chronic heart failure (CHF). Accordingly, the level of ACE inhibition was assessed by the pressor response to angiotensin (Ang) I in patients who had been treated with recommended doses of ACE inhibitors. METHODS AND RESULTS: Forty-two patients with CHF receiving 40 mg/d of a long-acting ACE inhibitor or 150 mg of captopril were studied. Radial artery systolic pressure (RASP, mm Hg) was monitored noninvasively. The pressor response to ascending doses of Ang I was evaluated in all patients before and after administration of the ARB valsartan. The pressor response to Ang I before and after valsartan was also reevaluated in 11 patients after the dose of ACE inhibitor was doubled for 1 week. RASP increased linearly with significantly ascending doses of Ang I despite treatment with ACE inhibitors. The pressor response to Ang I was blunted significantly by valsartan. Ang I-induced increase in RASP did not correlate with duration of ACE inhibitor therapy. After the dose of ACE inhibitors was doubled, the pressor response to Ang I was no longer different from that noted after valsartan. CONCLUSIONS: Recommended doses of ACE inhibitors do not fully inhibit ACE in CHF. The level of ACE inhibition achieved is not related to duration of ACE inhibitor therapy. Greater ACE inhibition is also achieved at twice the recommended doses of ACE inhibitors.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10694521&dopt=Abstract

ms3.hinet.net

BACKGROUND: This study measured morphological and hemodynamic changes and renin-angiotensin responsiveness of the left ventricle (LV) to beta-agonist stimulation in a Sprague-Dawley rat model of myocardial dysfunction produced by coronary artery ligation. METHODS: The LV function and papillary muscle mechanics were measured after 12 weeks of captopril treatment (2 g/l in drinking water) following left coronary artery ligation or a sham operation. Fifty-two rats were divided into three groups: those with sham operations, those with small infarcts (infarct size [IS] < 30% LV) and those with large infarcts (IS > or = 30% LV). RESULTS: The results showed that LV end-diastolic pressures were elevated in the large-infarct group regardless of treatment with the angiotensin-converting enzyme inhibitor (ACEI), and the LV weight was reduced in the ACEI-treated rats. In addition, the uninfarcted LV posterior papillary muscle of the large-infarct rats showed an impaired response to isoproterenol stimulation, including the developed tension, positive and negative rate of tension development, time to peak tension, and time to half relaxation. CONCLUSION: Chronic captopril treatment improved isoproterenol-stimulated muscle isometric function in rats following myocardial infarction, possibly through the beta-receptor pathway.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10695200&dopt=Abstract












online pharmacies || Hair Million herbal formula for hair loss and hair growth || Amoxicillin || Tramadol || Paxil || Rx Drugs USA, Prescription Drugs Online Pharmacy || Zithromax || online pharmacy || Antibiotics and prescription medications online literature || Antibiotics