133 research outputs found
Acute Lead Exposure Increases Arterial Pressure: Role of the Renin-Angiotensin System
Background: Chronic lead exposure causes hypertension and cardiovascular disease. Our purpose was to evaluate the effects of acute exposure to lead on arterial pressure and elucidate the early mechanisms involved in the development of lead-induced hypertension. Methodology/Principal Findings: Wistar rats were treated with lead acetate (i.v. bolus dose of 320 ÎŒg/Kg), and systolic arterial pressure, diastolic arterial pressure and heart rate were measured during 120 min. An increase in arterial pressure was found, and potential roles of the renin-angiotensin system, Na+,K+-ATPase and the autonomic reflexes in this change in the increase of arterial pressure found were evaluated. In anesthetized rats, lead exposure: 1) produced blood lead levels of 37±1.7 ÎŒg/dL, which is below the reference blood concentration (60 ÎŒg/dL); 2) increased systolic arterial pressure (Ct: 109±3 mmHg vs Pb: 120±4 mmHg); 3) increased ACE activity (27% compared to Ct) and Na+,K+-ATPase activity (125% compared to Ct); and 4) did not change the protein expression of the α1-subunit of Na+,K+-ATPase, AT1 and AT2. Pre-treatment with an AT1 receptor blocker (losartan, 10 mg/Kg) or an ACE inhibitor (enalapril, 5 mg/Kg) blocked the lead-induced increase of arterial pressure. However, a ganglionic blockade (hexamethonium, 20 mg/Kg) did not prevent lead's hypertensive effect. Conclusion: Acute exposure to lead below the reference blood concentration increases systolic arterial pressure by increasing angiotensin II levels due to ACE activation. These findings offer further evidence that acute exposure to lead can trigger early mechanisms of hypertension development and might be an environmental risk factor for cardiovascular diseaseThis study was supported by grants from CAPES (Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior) and CNPq (Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico)/FAPES (Fundação de Amparo Ă Pesquisa do EspĂrito Santo)/FUNCITEC (Fundação de CiĂȘncia e Tecnologia)(39767531/07), Brazil and from MCINN (Ministerio de Ciencia e InnovaciĂłn) (SAF 2009- 07201) and ISCIII (Instituto de Salud Carlos III) (Red RECAVA- Red TemĂĄtica de InvestigaciĂłn en Enfermedades Cardiovasculares del Instituto de Salud Carlos III, RD06/0014/0011), Spai
Acute lead-induced vasoconstriction in the vascular beds of isolated perfused rat tails is endothelium-dependent
Salt restriction in kidney diseaseâa missed therapeutic opportunity?
The importance of salt restriction in the treatment of patients with renal disease has remained highly controversial. In the following we marshal the current evidence that salt plays a definite role in the genesis of hypertension and target organ damage, point to practical problems of salt restriction, and report on novel pathomechanisms of how salt affects blood pressure and causes target organ damage
A Knowledge-Based System for Automated Architectural Code-Checking
Recent efforts to develop a knowledge-based expert system capable of reviewing an architectural design for conformance with the Life Safety Code (LSC) of the National Fire Protection Association are described. These efforts include the specification of a frame-based representation of floor-plans and the development of a rule-based representation of LSC requirements. The representation was developed to operate on top of a geometrical database contained in a CADD system, within which the expert system will be embedded. That part of the LSC relating to egress requirements and fire protection in hospitals was selected as the particular domain for this prototype. The work reported has implications for the representation of architectural information in the context of computer-aided design, as well as for the representation of legally mandated code requirements
An Art Therapy Case Study for a Childâs Socio Affective Profile and the Mother-Child Relationship in a Multi-Cultural Family -Focusing on Mother-Child Art Therapy Program based on Theraplay-
Chronic blood pressure effects of bufalin, a sodium-potassium ATPase inhibitor, in rats.
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