Zinc plasmático, cobre sérico y zinc y cobre eritrocitarios en adultos sanos de Buenos Aires / Plasmatic zinc, serum copper and erythrocyte zinc and copper levels in healthy adult people living in Buenos Aires

Se estudiaron adultos, clínicamente sanos, 21 varones (V) y 19 mujeres (M), de: edad (años): V: 48±14 (28-78); M: 41±14 (23-66); Índice de masa corporal (kg/m²): V: 26,7±2,3 (23,1-31,9); M: 22,2±3,5 (19,3-29,6). Se realizó una encuesta nutricional y se extrajo sangre en ayunas. Se realizaron las determinaciones de rutina del laboratorio clínico. Se determinó zinc en plasma (ZnPl), cobre en suero (CuS); en eritrocitos: Zinc (ZnGR) y cobre (CuGR), por espectrometría de absorción atómica. La totalidad de los V y M presentaron ingestas adecuadas de energía, proteínas, Zn y Cu. Los resultados expresados como: promedio ± desvío estándar y rangos fueron: ZnPl (μg/dL): V: 93±27 (49-161); M: 79±28 (42-157); ZnGR (μg/dL): V: 1.380±210 (1.110-2.010); M: 1.350±130 (1.090-1.520); CuS (μg/dL): V: 89±20 (40- 122); M: 93±28 (45-157). CuGR (μg/dL): V: 59±12 (37-78); M: 63±19 (30- 110). No se evidenciaron diferencias significativas entre V y M. Los resultados para la población estudiada fueron, percentilos 5 y 95, respectivamente: ZnPl: 49 a 131 μg/dL; ZnGR: 1.130 a 1.610 μg/dL; Zn/Hb: 34,4 a 47,5 μg/g; CuS: 45 a 124 μg/dL; CuGR: 36 a 78 μg/dL. Los valores de ZnPl y CuS se encuadraron dentro de los rangos de valores de referencia internacionales, sin diferencias significativas de acuerdo con el género.

Two groups of adult healthy people were studied: 21 males (M) and 19 females (F). Mean age (ys) was: M: 48±14 (28-78); F: 41±14 (23-66); body mass index (Kg/m²) was: M: 26.7±2.3 (23.1-31.9); F: 22.2±3.5 (19.3-29.6). A nutritional survey was recorded and mean daily intake of energy, protein, Zinc (Zn) and Copper (Cu) were calculated. Fasting blood samples were obtained in order to determine Hemoglobin (Hb), plasmatic Zn (PlZn), serum Cu (SCu), erythrocyte Zn (EZn) and erythrocyte Cu (ECu) levels. Zn and Cu were determined by AAS. Results were: mean±SD and ranges: PlZn (μg/dL): M: 93±27 (49-161); F: 79±28 (42-157); EZn (μg/dL): M: 1380±210 (1110-2010); F: 1350±130 (1090-1520); SCu (μg/dL): M: 89±20 (40-122); F: 93±28 (45-157). ECu (μg/dL): M: 59±12 (37-78); F: 63±19 (30-110). All individuals presented adequate intake of energy, protein, Zn and Cu. There were no significant differences between M and F for PlZn, EZn, Zn/Hb ratio, SCu and ECu. The results for the adult healthy population in Argentina, and which were in accordance with the international published values were: (percentiles 5 y 95, respectively): PlZn: 49 - 131 μg/dL; EZn: 1130 - 1610 μg/dL; Zn/Hb: 34,4 - 47,5 μg/g; SCu: 45 - 124 μg/dL; ECu: 36 - 78 μg/dL.

Zinc deficiency during growth: influence on renal function and morphology.

This study was designed to investigate the effects of moderate zinc deficiency during growth on renal morphology and function in adult life. Weaned male Wistar rats were divided into two groups and fed either a moderately zinc-deficient diet (zinc: 8 mg/kg, n=12) or a control diet (zinc: 30 mg/kg, n=12) for 60 days. We evaluated: renal parameters, NADPH-diaphorase and nitric oxide synthase activity in kidney, renal morphology and apoptotic cells in renal cortex. Zinc-deficient rats showed a decrease in glomerular filtration rate and no changes in sodium and potassium urinary excretion. Zinc deficiency decreased NADPH diaphorase activity in glomeruli and tubular segment of nephrons, and reduced activity of nitric oxide synthase in the renal medulla and cortex, showing that zinc plays an important role in preservation of the renal nitric oxide system. A reduction in nephron number, glomerular capillary area and number of glomerular nuclei in cortical and juxtamedullary areas was observed in zinc deficient kidneys. Sirius red staining and immunostaining for alpha-smooth muscle-actin and collagen III showed no signs of fibrosis in the renal cortex and medulla. An increase in the number of apoptotic cells in distal tubules and cortical collecting ducts neighboring glomeruli and, to a lesser extent, in the glomeruli was observed in zinc deficient rats. The major finding of our study is the emergence of moderate zinc deficiency during growth as a potential nutritional factor related to abnormalities in renal morphology and function that facilitates the development of cardiovascular and renal diseases in adult life.