|Source||United States Department of Energy Office of Scientific and Technical Information|
|Subject Keyword||RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT. ♦ ANGIOTENSIN ♦ BLOOD CHEMISTRY ♦ LEAD COMPOUNDS ♦ BIOLOGICAL EFFECTS ♦ CHRONIC EXPOSURE ♦ RENIN ♦ SECRETION ♦ DOSE-RESPONSE RELATIONSHIPS ♦ HYPERTENSION ♦ KIDNEYS ♦ MAN ♦ RATS ♦ ANIMALS ♦ BODY ♦ CARDIOVASCULAR AGENTS ♦ CARDIOVASCULAR DISEASES ♦ DISEASES ♦ DRUGS ♦ ENZYMES ♦ GLOBULINS ♦ HYDROLASES ♦ MAMMALS ♦ NONSPECIFIC PEPTIDASES ♦ ORGANIC COMPOUNDS ♦ ORGANS ♦ PEPTIDE HYDROLASES ♦ PRIMATES ♦ PROTEINS ♦ RODENTS ♦ SYMPTOMS ♦ VASCULAR DISEASES ♦ VASOCONSTRICTORS ♦ VERTEBRATES ♦ Chemicals Metabolism & Toxicology|
|Abstract||This paper reviews the chronic effects of lead exposure on the renin-angiotensin system in experimental animals and human beings. In rats, when lead exposure is begun several weeks after birth in doses that cause blood lead concentration (PbB) of 30 to 40 ..mu..g/L, the result is an increase in basal plasma renin activity (PRA) and renal renin concentration, with no change in the metabolic clearance of renin; this is presumptive evidence for increased renin secretion. PRA is also increased in 1-month-old animals whose exposure to lead (in doses that raise PbB to 9 ..mu..g/dL) was begun in utero. In contrast, older animals whose exposure was begun in utero manifest no change or a decrease in their PRA and renal renin concentration. Regardless of when the exposure is begun, lead can decrease the plasma concentration of angiotensin II at any given PRA, but the dose required for this effect is highly variable. The hypertension induced by lead exposure is associated with low PRA and a normal anigotensin II/PRA ratio. Chronic human exposure to lead also is associated with highly variable changes in PRA from study to study; it has been reported to be decreased under both basal and stimulated conditions, unchanged, or increased in a manner exponentially related to PbB. The human data are consistent with the tentative hypothesis that lead-exposed persons may have higher PRA than normal during the early periods of modest exposure but normal or depressed PRA following more chronic severe exposures. In a small preliminary study, blood lead concentration was found to be higher in high-renin hypertensive persons than in normotensive persons.|
|Learning Resource Type||Article|
|Publisher Place||United States|
|Journal||Environ. Health Perspect.|
|Organization||Univ. of Michigan, Ann Arbor (USA)|
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
For any issue or feedback, please write to email@example.com