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.
Brignone
J A
JA
Departamento de Bioquímica, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
de Brignone
C M
CM
Rodríguez
R R
RR
Marzi
A A
AA
de Mignone
I R
IR
Susemihl
M C
MC
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007700:Kinetics; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010052:Ovariectomy; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D012016:Reference Values
D004958:Estradiol