It has been suggested that the anticonvulsant effects of neuropeptide Y (NPY) could be mediated by the activation of Y2 and/or Y5 receptors. NPY Y1 receptor levels are known to decrease and Y2 to increase in rat models of epilepsy. By using an autoradiographic approach, we investigated whether epilepsy models (kainic acid and kindling) are also associated with changes in Y5 receptors. Compared with naive controls, [125I][Leu31, Pro34]PYY/BIBP3226-insensitive (Y5) binding sites in the hippocampus (strata oriens and radiatum of CA3 and CA1) and in the neocortex (superficial layers) were unchanged in sham-stimulated rats, but reduced by approximately 50% in kindled rats (seven days after the last stimulus evokes seizure), and further reduced (to approximately -90%) 1h after a kindled seizure. Additionally, Y5 receptor binding sites in the hippocampus and in the neocortex were unchanged 6h after kainic acid injection, but were highly reduced at 12 and 24h. No changes in Y5 binding levels w...
Decreased levels of neuropeptide Y5 receptor binding sites in two experimental models of epilepsy
BREGOLA, Gianni;ZUCCHINI, Silvia;SIMONATO, Michele
2000
Abstract
It has been suggested that the anticonvulsant effects of neuropeptide Y (NPY) could be mediated by the activation of Y2 and/or Y5 receptors. NPY Y1 receptor levels are known to decrease and Y2 to increase in rat models of epilepsy. By using an autoradiographic approach, we investigated whether epilepsy models (kainic acid and kindling) are also associated with changes in Y5 receptors. Compared with naive controls, [125I][Leu31, Pro34]PYY/BIBP3226-insensitive (Y5) binding sites in the hippocampus (strata oriens and radiatum of CA3 and CA1) and in the neocortex (superficial layers) were unchanged in sham-stimulated rats, but reduced by approximately 50% in kindled rats (seven days after the last stimulus evokes seizure), and further reduced (to approximately -90%) 1h after a kindled seizure. Additionally, Y5 receptor binding sites in the hippocampus and in the neocortex were unchanged 6h after kainic acid injection, but were highly reduced at 12 and 24h. No changes in Y5 binding levels w...I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
