Resumo

RUIZ E, Ana Z  e  KITTOK, Roger. Detection of the N-Methyl-D-Aspartate Receptor Subunit-1 (NMDAR-1) in the Hypothalamus of the Sheep by Western Blot Analysis.. Rev. Cient. (Maracaibo) [online]. 2008, vol.18, n.2, pp.148-153. ISSN 0798-2259.

The excitatory amino acids (EAAs), L-glutamate and aspartate, are considered the major endogenous neuroactive substances involved in excitatory neurotransmission. The N-methyl-D-aspartate receptor (NMDAR) is one of the main excitatory amino acid receptors. Exogenous activation of the NMDAR results in the release of gonadotrophin-releasing hormone (GnRH) from the hypothalamus and subsequent release of luteinizing hormone (LH) from the anterior pituitary. The present study had two aims: to standardize the optimal amount of total protein required to identify the NMDAR subtype-1 (NMDAR-1) in the hypothalamus of the sheep; to determine whether a difference exists in the distribution of NMDAR-1 in different hypothalamic regions (dorsal-rostral, ventral-rostral, dorsal-caudal, and ventral-caudal quadrant) in male sheep. The optimal amount of total hypothalamic protein required to visualize the NMDAR-1 was 100 µg. There was an effect of quadrant on the expression of NMDAR-1 in the hypothalamus of the intact male sheep. In particular, dorsal-rostral quadrant (31.5567 optical density ± 13.0831) expressed more receptor than ventral-caudal quadrant (17.1517 optical density ± 13.0831; P<0.05) and ventral-rostral quadrant (16.4683 optical density ± 13.0831; P<0.05). These data suggest that NMDAR is more expressed in the rostral area of the hypothalamus, where the cell bodies and axons of the GnRH neurons are localized. Thus, these data allow suggest that glutamatergic pathway potentially is involved in modulating the reproductive activity in the ovine.

Palavras-chave : NMDA receptor; Western blots; analysis; ovine.