Neurotensin in microdissected brain nuclei and in the pituitary of the lean and obese Zucker rats.
Neurotensin (NT) is a tridecapeptide common to the gastrointestinal tract and central nervous system which suppresses food intake when centrally injected in various regions of the hypothalamus. We measured neurotensin levels in several microdissected brain nuclei as well as in the pituitary in 10 obese hyperphagic Zucker (fa/fa) rats, 9 heterozygous Fa/fa and 5 Fa/Fa lean rats. The greatest NT concentration and content were observed in the anterior lobe of the pituitary in the median eminence and in the lateral preoptic area (500 to 1000 pg/area, 3 to 5 ng/mg protein). NT was also detected in the median preoptic area, paraventricular (PVN), supraoptic, ventromedian nuclei (VMN) (about 250 pg/nucleus, 1.5 to 2 ng/mg protein). The smallest amounts were found in the suprachiasmatic (SCH) and accumbens nucleus (about 100 pg/nucleus, 1 ng/mg protein) and the peptide was absent in the cortex. NT content in the obese rat was significantly lower in all brain nuclei examined except the accumbens nucleus. This was most evident in the three nuclei involved in the regulation of feeding behaviour: PVN (276 +/- 38 (Fa/Fa) vs 188 +/- 15 (fa/fa) pg/nucleus, P less than 0.05), VMN (226, +/- 21 (Fa/Fa) vs 75 +/- 22 (fa/fa) pg/nucleus, P less than 0.001), and SCH (98 +/- 14 (Fa/Fa) vs 52 +/- 11 (fa/fa) pg/nucleus, P less than 0.05). There was no difference in the pituitary lobes between lean and obese rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Beck
B
B
INSERM U.308, MRCA, Nancy, France.
Burlet
A
A
Nicolas
J P
JP
Burlet
C
C
D000818:Animals; D001835:Body Weight; D004435:Eating; D007031:Hypothalamus / Q000032:analysis*; D009496:Neurotensin / Q000032:analysis* / Q000502:physiology; D010903:Pituitary Gland, Anterior / Q000032:analysis*; D011863:Radioimmunoassay; D051381:Rats; D011924:Rats, Zucker
D009496:Neurotensin