Effects of anti-hypertensive drugs on epithelial tissues on oral cavity: experimental study

• Grant number: 06/00926-7
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2006
• End date: August 31, 2008
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Marilena Chinali Komesu
• Grantee: Marilena Chinali Komesu
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Hypertension is a common adult chronic systemic disease. Its prevalence tends to rise with age, and it is generally asymptomatic until late in course. In Brazil, 20% of adults and 50% of those with more than 50 years age are hypertensive. There is a common belief that hypertensive drugs, but not hypertension per se may be a major factor for oral lesions, unless at end-stages of the disease. So, the oral lesions/hypertension relationship is mostly understood as associated to anti-hypertensive medication. Dentists must be concerned about the adult patients with hypertension, whatever they are undiagnosed, noncompliant, or medically treated. The detection of hypertensive patients is important from several aspects. Significant complications of hypertension status may be avoided of minimized by early detection and treatment of hypertension; potential life-threatening complications can be prevented by not performing dental treatment for uncontroled hypertensive treatment; and anti-hypertensive treatment may have some important adverse effects which lead to dental treatment complications. Long-term complications associated with hypertension may be heart disease, kidney disease, stroke, retinopathy, and peripheral artery disease. The activity of many anti-hypertensive drugs may be decreased by the prolonged use of nonsteroidal anti-inflammatory drugs, and some anti-hypertensive drugs can potentiate the action of barbiturates or other sedatives.Patients on anti-hypertensive drugs may present side effects such as orthostatic hypotension, lidhenoid reaction, gingival hyperplasia or dry mouth. Stress and anxiety can raise blood pressure, and excessive doses of vasoconstrictor in anestetic agent can increase the blood pressure and cause arrhytmia in some patients. Patients with severe hypertension should not be given any anesthetic conteining even small amounts of epihephrine for any dental treatment, however, controlled hypertenive patients may get up to 2 cartridges of 1.8ml of lidocaine with 1:100,000 epinephrine without any problem related to increased blood pressure or arrytmia.The objective of our study was to observe the effects of different anti-hypertensive drugs on oral epithelial and related tissues. There will be used Rattus norvegicus - Wistar, body weight 180- 200g. For experimental hypertension (10 animals) it will be used L-NMMA (N-monomethyl-L-arginine) a specific inhibitor of endothelium-derived nitric oxide, known to play an important role in the regulation of blood pressure. Anti-hypertensive will be: diuretic - Higroton (Geigy) 1mg/kg ever 48 hours (10 animals); Ca+ channals blockers - Amlodipine (Biosintética) 0.15mg/kg/d (10 animals);  bloquckers Atenolol (Biosintética)1mg/kg/d (10 animals); Angiotensin Converting Enzymes inhibitors - Captopril (Biosintética) 1mg/kg/d (10 animals). All the medicines will be given by gavage. Control group – 5 animals.Five animals of each group will be sacrificed at days 7 and 30 days of treatment. Control animals will be sacrificed by the end of the experimental 30 days period. For the sacrifice and collection of the material, the animals will be anesthetized then sacrificed by cardiac and respiratory breakdown during surgery. Tissues will be removed and fixed (10% formalin - 24 hours). The tissue specimens will be dehydrated and paraffin embedded. Sections will be prepared (6m) and placed on glass slides ready for staining. The slides were stained by hematoxylin and eosin (HE) for routine histological evaluation of tissues, and molecular biology techniques will be used when necessary and opportune. It will be evaluated the structural condition of the stratified and glandular epithelial tissues, on control, hypertensive, and the animals under anti-hypertensive therapy. The obtained data will be presented as tables, figures and graphics and adequade statistical tests will be used.. (AU)