Erythrocyte, lipid peroxidation and antioxidant enzymes in hypervitaminotic A rats and their modification by dietary protein.

Rats fed excess vitamin A showed decreased body weight gain and protein efficiency ratio. In rats fed low protein vitamin A level increased in liver but with an associated decrease in plasma. These changes were reversed in high protein fed state. The amount of protein in diet had little effect on haemoglobin level in erythrocyte, but excess vitamin A in diet significantly decreased haemoglobin level in erythrocyte. Lipid peroxidation (LP) increased in rats fed low protein and decreased in high protein fed rats. Rats fed high protein and excess vitamin A showed minimum level of LP. Result showed that high protein in diet increased the levels of antioxidant enzymes, catalase and superoxide dismutase (SOD) and that excess vitamin A supplementation functions synergistically with high protein in diet to increase antioxidant enzymes level.

Alterations in kidney enzyme pattern in acute hypervitaminosis A

The relation of excessive doses of vitamin A with various kidney pathologies is well known however, information concerning the relation of kidney enzyme activity with acute hypervitaminosis A is rather scarce. In this study we describe the kidney enzymatic alterations observed in rats that received daily intramuscular injectiosn of 10.000, 30.000, 50.000 and 100.000IU of vitamin A palmitate (VA) during seven days (TREATED GROUPS). A comparison is made with the enzyme activity in healthy rats pairfed and treated with sodium palmitte by intramuscular injection (CONTROL GROUP). The treated rats showed a proportional increase (<0.05) in activity of acid maltase, transaminases or aminotransferase (GOT and GPT), alkaline phosphatase (ALP) and acid protease with all doses of VA administered, Amylase, lipase and arginase tend to decrease (p<0.05) in activity only with doses of 50.000 and 100.000 I.U. of VA. Several factors are responsible for these findings, such as kidney necrosis due to release of lysosomal acid hydrolases produced by hypervitaminosis A.

Modificaciones del contenido de fosforo hepatico y renal en cobayos tratados con dosis elevadas de vitamina A alcohol (retinol) / Alterations in the liver and kidney phosphorus in guinea pigs exposed to high doses of vitamin A (retinol)

In this study, the serum, urinary, hepatic and renal levels of total inorganic phosphorus (Pi) were determined in guinea pigs treated with 100,000 U.I. of vitamin A, dissolved in Tween Span, given each day by intramuscular injections during seven days (treated group), and compared with the levels in healthy guinea pigs which were given the same feed as the treated group, and received the same amount of Tween Span (control group). The activity of the enzymes alkaline phosphatase and acid phosphatase was simultaneously determined in liver and kidneys of both groups, and the phospholipid content in serum and tissue was also determined. The treated group did not show changes in serum and urinary phosphorus as compared with the control group. Liver and kidney of the treated group showed an increase in total Pi (p <0.05). In this group a definite increase (p < 0.05) was also observed both in serum and tissue levels of phospholipids, as well as in the activity of the liver and kidney enzymes studied. These results suggest that phosphorus enters the blood stream in the form of lipid complexes (phospholipids) that are involved in certain characteristic functions

Estudo de alguns parâmetros fisiológicos em hamsters submetidos à hipervitaminose A / Study of some physiological parameters in hamsters submitted to hypervitaminose A

A administraçäo diária de 150 UI de vitamina A/grama de peso corporal pelo período de 10 dias, em hamsters, tiveram os seguintes resultados nos parâmetros fisiológicos estudados: 1) o tratamento com vitamina A causa uma reduçäo no hematócrito e hemoglobina; 2) houve aumento no nível glicêmico do grupo tratado; 3) o nível de proteína plasmática foi menor no hamsters hipervitaminótico A

Modificaciones del metabolismo proteico en la hipervitaminosis A aguda, en ratas / Changes of the protein metabolism in acute hypervitaminosis A, in rats

Se presentó el efecto de 100.000 U.I. (700.000 U.I. en total) de vitamina A, administradas diariamente, durante siete días sobre diversos marcadores séricos y hepáticos relacionados con el metabolismo proteico, en ratas. Los resultados obtenidos indican que la hipervitaminosis A aguda determina una disminución significativa de las proteínas totales, del ARN, de los aminoácidos y de la ureogénesis a nivel hepático y, de la albúmina, de las alfa-globulinas y de los niveles de la urea y de los aminoácidos en suero. Por otra parte, se encontró un aumento significativo en la concentración del ADN hepático y en las globulinas gama y ß séricas. Se discuten los resultados obtenidos y se concluye que la hipervitaminosis A aguda determina profundas alteraciones en el metabolismo proteico

Hipervitaminose A experimental no rato: estudo morfológico e morfométrico do cortex e da medula da adrenal / Experimental hypervitaminose A in the rat. Morfological and morfometric study of the cortex and medular of the adrenal

A administraçäo de 200 U. I. de vitamina A/grama de peso corporal, no rato, permitiu aos autores observarem: 1) O peso da glândula adrenal apresentou-se maior no animal com hipervitaminose A (19,58 mg) quando comparado ao animal controle (10,86 mg); 2) A zona glomerulosa do côrtex adrenal do rato tratadfo apresentou-se histologicamente, com células ligeiramente mais volumosas e com citoplasma mais abundante, mais acidófilo e com núcleos pouco mais volumosas. As zonas fasciculada a reticular também apresentaram células mais volumosas, com citoplasma mais abundante, com maior número de vacúolos e núcleos de volume maior, além de vasos bem dilatados; 3) A medula adrenal no animal tratado, revelou células com citoplasma menos granuloso, vasos dilatadores, congestos e edema. Os dados acima foram confirmados com o emprego de técnicas morfométricas