RESUMEN
OBJECTIVE: Recent studies have shown that leptin receptor is expressed in human and rat pituitary glands. The expression of leptin receptor in rats whose dams were malnourished during lactation has not been previously reported. METHODS: We examined leptin receptor expression in the pituitary gland of adult rats whose dams were assigned to one of the following groups during lactation: control diet, protein-restricted diet (8% protein), or energy-restricted diet (the control diet fed in restricted quantities that were calculated according to the mean ingestion of the protein-restricted group). After weaning, all pups had free access to the control diet until they reached adult age, at which time leptin receptor expression in the pituitary was analyzed by immunohistochemistry. RESULTS: Adult animals from protein- and energy-restricted dams had a higher expression of leptin receptor in pituitary tissue, normal serum leptin concentrations, higher serum tri-iodothyronine concentrations, and lower thyroid-stimulating hormone concentrations than did the control rats. CONCLUSIONS: In the fed state, leptin has a stimulatory effect on release of thyroid-stimulating hormone. The higher expression of leptin receptor in the pituitary of animals from protein- and energy-restricted dams may suggest a postreceptor failure in leptin action. This higher receptor expression may have allowed a greater inhibition of release of thyroid-stimulating hormone.
Asunto(s)
Lactancia/metabolismo , Leptina/sangre , Hipófisis/metabolismo , Desnutrición Proteico-Calórica/metabolismo , Receptores de Superficie Celular/metabolismo , Tirotropina/metabolismo , Animales , Animales Lactantes , Dieta con Restricción de Proteínas , Dieta Reductora , Femenino , Inmunohistoquímica , Desnutrición Proteico-Calórica/fisiopatología , Distribución Aleatoria , Ratas , Ratas Wistar , Receptores de Superficie Celular/inmunología , Receptores de LeptinaRESUMEN
The aim of this study was to evaluate the hypothesis that the association between nutritional status and gender of rat pups during the early postnatal period (lactation) induces changes in glucose homeostasis and blood pressure of the pups when becoming adults. The results indicate that undernourishment during lactation is associated with gender and affects glucose homeostasis and blood pressure of female adults. In our experiments, the blood glucose level at the end of a clamping was significantly different in the undernourished females (FU) compared with the female controls (FC) (FC: 11.2 +/- 0.9 mmol/l; FU: 26.9 +/- 2.1 mmol/l; p