Inhibition of opioid systems in the hypothalamus as well as the mesolimbic area suppresses feeding behavior of mice

摘要: Opioid receptors, especially μ-opioid in the ventral tegmental area (VTA) and nucleus accumbens (NAcc) are reported to regulate food motivation. However, roles of μ-, δ- κ-opioid receptors not fully understood. Moreover, since distribute hypothalamus, these hypothalamus might feeding behavior. Thus, present study investigated role VTA, NAcc regulation Male ICR mice were subjected a test after deprivation for 16h. The mRNA levels proopiomelanocortin (POMC), preproenkephalin (PENK) prodynorphin (PDYN), precursors endogenous opioid peptides, measured by reverse transcription-polymerase chain reaction (RT-PCR). systemic injection non-selective (naloxone) selective μ (β-funaltrexamine; β-FNA), δ (naltrindole) κ (norbinaltorphimine; norBNI) receptor antagonists markedly reduced intake. In contrast, preferential (morphine), (KNT-127) (U-50,488) agonists did change POMC, PENK PDYN decreased midbrain deprivation, whereas PDYN, but striatum. naloxone into NAcc, VTA lateral (LH), ventromedial significantly β-FNA naltrindole LH, or norBNI LH These results indicate that play more important behavior than those NAcc.