Kotz C M, Glass M J, Levine A S, Billington C J
Departments of Food Science and Nutrition, University of Minnesota, Saint Paul 55108, USA.
Am J Physiol Regul Integr Comp Physiol. 2000 Feb;278(2):R499-503. doi: 10.1152/ajpregu.2000.278.2.R499.
Naltrexone (NLTX) in the nucleus of the solitary tract (NTS) decreases feeding induced by neuropeptide Y (NPY) in the paraventricular nucleus (PVN). We sought to determine the NTS region most sensitive to NLTX blockade of PVN NPY-induced feeding. Male Sprague-Dawley rats were fitted with two cannulas; one in the PVN and one in a hindbrain region: caudal, medial, or rostral NTS or 1 mm outside the NTS. Animals received NLTX (0, 1, 3, 10, and 30 microg in 0.3 microl) into the hindbrain region just prior to PVN NPY (0.5 microg, 0.3 microl) or artificial cerebrospinal fluid (0.3 microl). Food intake was measured at 2 h following injection. PVN NPY stimulated feeding, and NLTX in the medial NTS significantly decreased NPY-induced feeding at 2 h, whereas administration of NLTX in the other hindbrain regions did not significantly influence PVN NPY induced feeding. These data suggest that opioid receptors in the medial NTS are most responsive to feeding signals originating in the PVN after NPY stimulation.
孤束核（NTS）中的纳曲酮（NLTX）可减少室旁核（PVN）中神经肽Y（NPY）诱导的进食。我们试图确定对NLTX阻断PVN中NPY诱导的进食最敏感的NTS区域。雄性Sprague-Dawley大鼠植入两根套管，一根置于PVN，另一根置于后脑区域：尾侧、内侧或 Rostral NTS 或 NTS 外 1 毫米处。在向PVN注射NPY（0.5微克，0.3微升）或人工脑脊液（0.3微升）之前，动物向后脑区域注射NLTX（0、1、3、10和30微克，溶于0.3微升）。注射后2小时测量食物摄入量。PVN NPY刺激进食，内侧NTS中的NLTX在2小时时显著减少NPY诱导的进食，而在其他后脑区域注射NLTX对PVN NPY诱导的进食没有显著影响。这些数据表明，内侧NTS中的阿片受体对NPY刺激后源自PVN的进食信号反应最为敏感。
