Effect of ovarian hormones upon liver mitochondrial function in diabetic rats.

In the present study it is shown that streptozotocin (SZ)-induced chronic diabetes of female albino rats produced significant alterations in liver mitochondrial function after 30-35 days of diabetes. The disturbances were as follows: (1) a significant fall of the mean values of the respiratory control ratio and of state 3 of respiration using three substrates, 3-hydroxybutyrate, malate-glutamate and succinate, and (2) a significant increase of the mean damping factor of the oscillatory osmotic variations (with valinomycin as K+ ionophore and succinate as substrate). The same mitochondrial function parameters were analyzed for comparison in control non-diabetic rats (group N) and in the following groups of female rats with chronic diabetes: intact (group I), oophorectomized (6 days after the injection of SZ) (group O), and oophorectomized with restitution therapy of 17 beta-estradiol (from the operation until the day before killing) (group O + Eol). The O group showed significantly higher values of the respiratory control ratio and of state 3 of respiration and significantly lower damping factors than group I. The restitution treatment in the O + Eol group restored the mitochondrial functions assayed to values similar to those of group I. These data provide strong evidence that estrogens exert a negative effect at the molecular level upon impaired liver mitochondrial functions in SZ-induced diabetes.

Organochlorinated pesticides in the Argentine Antarctic sector and Atlantic coastline waters.

The presence of organochlorinated pesticides in water samples drawn in the Argentine Antarctic Sector and Atlantic coastline has been proved. In general, these samples showed quantities that varied between a few hundredths of a ppmm to slightly more than 1 ppmm, although in some cases and for certain pesticides, depending on the locations, the levels found were definitely higher. With the exception of Dieldrin, which appeared in only one sample/in what would seem to be its course few hundredths of a ppm, to slightly more than 1 ppmm, although in some cases and for certain pesticides found were the same as those reported in previous investigations. The isolated cases of high pesticide contents in water samples drawn at wharves and of snow in the vicinity of Almirante Brown Base show up clearly the influence of human activity on the contamination of the environment.