Clinical Use and Pathogenetic Basis of Laboratory Tests for the Evaluation of Primary Arterial Hypertension

This review focuses on the laboratory biochemical tests that are useful in the diagnostic approach to the hypertensive patient. A "minimal" diagnostic laboratory work-up, including a small number of tests that are simple and relatively inexpensive, is first described. Because these tests provide basic information on the presence of major cardiovascular (CV) risk factors and target organ damage, and might give some clues to the presence of a secondary form of hypertension (HT), they should be performed on all patients presenting with HT. Other tests that are aimed at assessing the overall CV risk, a major determinant of prognosis that dictates the therapeutic strategy in the individual HT patient, are then discussed. They allow identification of major CV risk factors and associated clinical conditions which, if present, lead to a substantial change of therapeutic strategy. The role of C-reactive protein as a marker of atherosclerosis and its predictive value for CV events are also discussed. Finally, a section is devoted to tests that are currently confined to research purposes, such as markers of endothelial function including endothelin-1, homocysteine and genetic analysis.

Four-week intravenous repeated dose toxicity study of L-cysteine in male rats

A 4-week intravenous repeated dose toxicity study of L-cysteine (L-Cys) was conducted in male Sprague-Dawley rats to investigate in detail the toxic effects of this compound and to determine the dose level at which these toxic effects are observed following repeated intravenous administration. Male rats were randomly allocated to 4 groups to receive L-Cys by intravenous administration at dosages of 0, 100, 300, and 1,000 mg/kg body weight/day. Body weight gain was significantly suppressed throughout the study period in the 1,000-mg/kg group, although food consumption was reduced only on study day 3. A decrease in spontaneous activity, salivation, stereotypy, ptosis, and tremor were observed in the 1,000-mg/kg group. Mild anemia characterized by decreases in hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin and an increase in the reticulocyte count was also noted in the 1,000-mg/kg group. Histopathological examination showed sperm granulomas in the epididymis and necrosis of the Purkinje cells and granular layer in the cerebellum in the 1,000-mg/kg group. Slight tubular basophilia with blood or hyaline casts was observed in the kidney in the 300-mg/kg and 1,000-mg/kg groups, associated with proteinuria or occult blood in urinalysis. Additional studies are needed to clarify the causes for these toxicological findings by excess of L-Cys.