Dual Angiotensin II and Endothelin Receptor Antagonists

Combined Antihypertensive Therapies That Increase Expression of Cardioprotective Biomarkers Associated With the Renin-Angiotensin and Kallikrein-Kinin Systems

Antihypertensive pharmacological treatments focus on the use of angiotensin-converting enzyme (ACE) inhibitors, AT1 receptor antagonists, and beta-blockers as single and combined treatments. The effect of single treatments on the mRNA expression of some components of the renin-angiotensin system has been studied, but not the effect of combined treatments. This study determined the expression of the AT1, AT2, B1, and B2 receptors and of the enzymes ACE and ACE2 in hypertensive rats treated with captopril-propranolol or losartan-propranolol. Methods: The mRNA expression of the receptors and enzymes was determined by reverse transcription-quantitative polymerase chain reaction in the aorta of spontaneously hypertensive rats under different treatments. Results: Rats under combined treatments showed a decrease in the expression of AT1 and ACE, and an increase in the expression of the B1 receptor (captopril + propranolol group: 0.43 ± 0.046, 2.243 ± 0.269, 3.356 ± 0.418; Group: losartan + propranolol: 0.727 ± 0.071, 0.852 ± 0.102, 1.277 ± 0.131 compared to the spontaneously hypertensive group: 1 ± 0.212, 1 ± 0.192, 1 ± 0.214). This decrease in the expression of ACE and AT1 suggests a reduction in the expression of Ang II that could be related to a lower response to this vasoconstrictor. An increase in the expression of B1 would improve vasodilation, which would be a beneficial effect of combined therapies for hypertension.

The possible potential therapeutic targets for drug induced gingival overgrowth

Gingival overgrowth is a side effect of certain medications. The most fibrotic drug-induced lesions develop in response to therapy with phenytoin, the least fibrotic lesions are caused by cyclosporin A, and the intermediate fibrosis occurs in nifedipine-induced gingival overgrowth. Fibrosis is one of the largest groups of diseases for which there is no therapy but is believed to occur because of a persistent tissue repair program. During connective tissue repair, activated gingival fibroblasts synthesize and remodel newly created extracellular matrix. Proteins such as transforming growth factor (TGF), endothelin-1 (ET-1), angiotensin II (Ang II), connective tissue growth factor (CCN2/CTGF), insulin-like growth factor (IGF), and platelet-derived growth factor (PDGF) appear to act in a network that contributes to the development of gingival fibrosis. Since inflammation is the prerequisite for gingival overgrowth, mast cells and its protease enzymes also play a vital role in the pathogenesis of gingival fibrosis. Drugs targeting these proteins are currently under consideration as antifibrotic treatments. This review summarizes recent observations concerning the contribution of TGF-β, CTGF, IGF, PDGF, ET-1, Ang II, and mast cell chymase and tryptase enzymes to fibroblast activation in gingival fibrosis and the potential utility of agents blocking these proteins in affecting the outcome of drug-induced gingival overgrowth.