El vanadio, un elemento ambiguo / Vanadium, an ambiguous element

El vanadio (V) se encuentra en 68 minerales diferentes, en los combustibles derivados del petróleo y el carbón y se utiliza principalmente en la industria metalúrgica. Para los humanos, la principal fuente de exposición al V es la contaminación atmosférica producida por la quema de combustibles. En los animales se ha demostrado que algunos compuestos del V son hepatotóxicos, nefrotóxicos, neurotóxicos, carcinogénicos y que afectan a la reproducción y al desarrollo de los fetos y lactantes. Sin embargo, los efectos toxicológicos finales, motivo de preocupación para las personas son la genotoxicidad y la irritación de las vías respiratorias. Por otra parte, los compuestos del V han sido objeto de investigación como agentes que disminuyen los niveles séricos de glucosa, como antihipertensivos, como anorexígenos y como anticancerígenos. El V, de efectos biológicos notables, debe ser más estudiado con el fin de conocer los mecanismos de su acción biológica y para poder determinar tanto los riesgos a su exposición como sus posibles usos farmacológicos en beneficio humano.

Vanadium (V) occurs in about 68 minerals and in fossil fuels and it is mainly used in steel industry. Air pollution produced by oil and coal burning is the main exposure source for human beings. Reproductive and developmental toxicity, hepatotoxicity, nephrotoxicity, neurotoxicity and carcinogenicity have been found in some vanadium compound exposed animals. Nevertheless, the toxicological end-points of concern for humans are genotoxicity and respiratory tract irritation. On the other hand, V compounds have been studied as anti-diabetic, as antihypertensive, as anorexigen and as anti-carcinogenic. V, which has remarkable biological effects should be studied in order to elucidate its biological mechanisms and to determine either its expositional risks or its pharmacological properties for human benefit.

Determination of vanadium accumulation in onion root cells (Allium cepa L) and its correlation with toxicity

The vanadium is a metal that presents great interest from the toxicological point of view, because of the numerous alterations that can take place in different biological systems. This work evaluated the capacity of vanadium accumulation and its correlation with genotoxic effects in root cells of Allium cepa L. The bulbs were cultivated in renovated filtered water each 24 h, at a temperature of 25 +/- 0.5 degrees C, in darkness and constant aeration. Treatments were carried out under the same experimental conditions, using water solutions of vanadium of 25, 50, 75 and 100 microg/g for 0, 12, 24, 48 and 72 h. A control was carried out where metal solution was substituted by distilled water. After the treatment, the meristems were fixed with alcohol--acetic acid (3:1) and stained according to the technique of Feulge n. The capacity of accumulation was determined by GFAAS. The analysis of the results revealed an accumulation of the metal for all times and concentrations. No correlation was presented among vanadium accumulation, growth and mitotic index; however, positive correlation was given with the induction of chromosomic aberrations. In conclusion, vanadium is able to induce cytotoxic effect in the exposed roots, but only genotoxic effect was correlated with metal accumulation.

Orally active insulin mimics: where do we stand now?

The war against diabetes through the development of new drugs is an ongoing continuous process to counter the alarming global increase in the prevalence of diabetes and its complications, particularly in developing countries like India. Unfortunately, the speed with which our knowledge of diabetes and its effects is expanding is not matched by the availability of new drugs. Following the identification of the insulin receptor (IR), its intrinsic kinase activity and molecular cloning, many studies have looked at IR as an ideal drug target. This review summarizes in brief the latest advancements in this field with particular reference to the current situation in respect of the development of orally active insulin mimetics in the treatment of type 2 diabetes.

Influence of vanadium on lipid profiles and lipid peroxidation in rat liver

Twenty four adult male Sprague-Dawley rats were administered sodium matavanadate [2.5 mg/kg body wt] for 7 consecutive days by intraperitoneal route. Results revealed significant diminution in the levels of phospholipids, cholesterol and cerebrosides, but significant increment in gangliosides contents in rat liver following vanadium-treatment. Occurrence of lipid peroxidation was also accelerated. These studies have implicated that vanadium-induced stimulation of lipid peroxidation was the event leading to oxidative degradation of lipids in rat liver. However, malfunctioning of gangliosides led to their increment