Antisense oligodeoxynucleotide (AS ODN) probes directed against the α-subunit of different G-proteins have been used to differentiate feeding responses in rats elicited by different opioid agonists, including morphine, β-endorphin and dynorphin. Furthermore, antisense probes directed against Goα, but not Gsα, Gqα or Giα, significantly reduced nocturnal feeding in rats. The present study examined whether food intake and weight changes elicited by 24 h of food deprivation were significantly altered by ventricular administration of antisense probes directed against either Giα1, Giα2, Giα3, Gsα, Goα, Gqα or Gx/zα as well as a control nonsense probe in rats. Deprivation-induced weight loss was significantly enhanced by antisense probes directed against Gsα and Gx/zα, whereas weight recovery 24 h following reintroduction of food was significantly reduced by antisense probes directed against Giα2, Gqα and Goα. Selective antisense probe effects were noted for deprivation-induced intake with Gsα and Gqα probes exerting the greatest reductions, Gx/zα, Giα2, and Giα3 probes exerting lesser effects, and Giα1 and Goα probes failing to affect deprivation-induced intake. Importantly, the nonsense control probe failed to alter deprivation-induced intake or weight. The reductions in deprivation-induced intake by AS ODN probes directed against Gsα or Gqα were not accompanied by any evidence of a conditioned taste aversion. These data indicate important distinctions between G-protein mediation of different effector signaling pathways mediating feeding responses elicited under natural (e.g. nocturnal feeding) and regulatory challenge (e.g. food deprivation) conditions.
- Antisense oligodeoxynucleotides
- Food deprivation