TY - JOUR
T1 - Selective decrease of Na+/K+-ATPase activity in the brain of hypothyroid rats
AU - Pacheco-Rosado, Jorge
AU - Arias-Citalán, G.
AU - Ortiz-Butrón, R.
AU - Rodríquez-Páez, L.
PY - 2005
Y1 - 2005
N2 - The present work was performed in order to know if mild hypothyroidism in rats modifies the activity of the Na+/K+-ATPase in different regions of the brain. Male Wistar rats (300-350 g) were randomly divided into three groups: 1) control group (n=8) drank tap water. 2) hypothyroid group (n=8) treated with 60 mg/kg of methimazole in drinking water; and 3) replaced group (n=8) treated with 60 mg/kg of methimazole plus 35 μg/kg of thyroid hormone (T3) in drinking water. After four weeks of treatment, the rats of all groups were sacrificed by decapitation. The cortex, amygdala, hippocampus and cerebellum were dissected and frozen at -70°C until assay. For enzymatic assay, the tissues were homogenized. The Na+/K+-ATPase activity was determined by quantifying inorganic phosphate after the samples were incubated with ATP in the presence and absence of 1 mM ouabain. The Na+/K+-ATPase activity is expressed as μmoles Pi/hr/mg protein. The results showed that the Na +/K+-ATPase activity in the cortex, amygdala and hippocampus, but not in cerebellum, was lower in hypothyroid group than in control group (p<0.05). The co-administration of methimazole and T 3 avoided the decrease of Na+/K+-ATPase activity, except in amygdala. According to the results obtained we concluded that methimazole treatment decreased the Na+/K+-ATPase activity in the brain's regions which are related to seizures onset. That decrement in enzyme activity was avoided with the co-administration of thyroid hormone.
AB - The present work was performed in order to know if mild hypothyroidism in rats modifies the activity of the Na+/K+-ATPase in different regions of the brain. Male Wistar rats (300-350 g) were randomly divided into three groups: 1) control group (n=8) drank tap water. 2) hypothyroid group (n=8) treated with 60 mg/kg of methimazole in drinking water; and 3) replaced group (n=8) treated with 60 mg/kg of methimazole plus 35 μg/kg of thyroid hormone (T3) in drinking water. After four weeks of treatment, the rats of all groups were sacrificed by decapitation. The cortex, amygdala, hippocampus and cerebellum were dissected and frozen at -70°C until assay. For enzymatic assay, the tissues were homogenized. The Na+/K+-ATPase activity was determined by quantifying inorganic phosphate after the samples were incubated with ATP in the presence and absence of 1 mM ouabain. The Na+/K+-ATPase activity is expressed as μmoles Pi/hr/mg protein. The results showed that the Na +/K+-ATPase activity in the cortex, amygdala and hippocampus, but not in cerebellum, was lower in hypothyroid group than in control group (p<0.05). The co-administration of methimazole and T 3 avoided the decrease of Na+/K+-ATPase activity, except in amygdala. According to the results obtained we concluded that methimazole treatment decreased the Na+/K+-ATPase activity in the brain's regions which are related to seizures onset. That decrement in enzyme activity was avoided with the co-administration of thyroid hormone.
UR - http://www.scopus.com/inward/record.url?scp=30144438893&partnerID=8YFLogxK
M3 - Artículo
C2 - 16416660
AN - SCOPUS:30144438893
SN - 0083-8969
VL - 48
SP - 52
EP - 54
JO - Proceedings of the Western Pharmacology Society
JF - Proceedings of the Western Pharmacology Society
ER -