TY - JOUR
T1 - Chronic food restriction and acute food deprivation decrease mRNA levels of opioid peptides in arcuate nucleus
AU - Kim, Eun Mee
AU - Welch, Catherine C.
AU - Grace, Martha K.
AU - Billington, Charles J.
AU - Levine, Allen S.
PY - 1996
Y1 - 1996
N2 - Although opioid administration induces food intake, the relationship between endogenous opioid synthesis and food consumption is unclear. Two studies examined the effects of food restriction and deprivation on opioid mRNA levels in the arcuate nucleus (ARC) of the rat. Body weight significantly decreased following food restriction and deprivation (P < 0.0001). In experiment 1, food restriction of 10, 20, 30, and 40% (g) of ad libitum intake for 14 days decreased proDynorphin (proDyn), proEnkephalin (proEnk), and proO-piomelanocortin (POMC) mRNA levels in a linear fashion relative to changes in body weight (r = 0.398, P = 0.011; r = 0.455, P = 0.0028; r = 0.292, P = 0.0642, respectively). In experiment 2, 48 h deprivation significantly decreased mRNA levels of proDyn and POMC by 23.7% (P < 0.05) and 45.6% (P < 0.01), respectively, whereas 24 h food deprivation decreased POMC mRNA by 43.0% (P < 0.01). proEnk mRNA was not affected by 24- or 48-h food deprivation. Restricting food intake suppressed mRNA levels of proDyn, proEnk, and POMC by 29.7, 22.3, and 44.4%, respectively, in 20% restricted rats and by 35.5, 26.8, and 45.6%, respectively, in 40% restricted rats (P < 0.01). It appears that ARC mRNA levels of proDyn, proEnk, and POMC are directly related to the amount of food consumed and/or changes in body weight in food-restricted and food-deprived rats.
AB - Although opioid administration induces food intake, the relationship between endogenous opioid synthesis and food consumption is unclear. Two studies examined the effects of food restriction and deprivation on opioid mRNA levels in the arcuate nucleus (ARC) of the rat. Body weight significantly decreased following food restriction and deprivation (P < 0.0001). In experiment 1, food restriction of 10, 20, 30, and 40% (g) of ad libitum intake for 14 days decreased proDynorphin (proDyn), proEnkephalin (proEnk), and proO-piomelanocortin (POMC) mRNA levels in a linear fashion relative to changes in body weight (r = 0.398, P = 0.011; r = 0.455, P = 0.0028; r = 0.292, P = 0.0642, respectively). In experiment 2, 48 h deprivation significantly decreased mRNA levels of proDyn and POMC by 23.7% (P < 0.05) and 45.6% (P < 0.01), respectively, whereas 24 h food deprivation decreased POMC mRNA by 43.0% (P < 0.01). proEnk mRNA was not affected by 24- or 48-h food deprivation. Restricting food intake suppressed mRNA levels of proDyn, proEnk, and POMC by 29.7, 22.3, and 44.4%, respectively, in 20% restricted rats and by 35.5, 26.8, and 45.6%, respectively, in 40% restricted rats (P < 0.01). It appears that ARC mRNA levels of proDyn, proEnk, and POMC are directly related to the amount of food consumed and/or changes in body weight in food-restricted and food-deprived rats.
KW - food-deprived rats
KW - food-restricted rats
KW - opioid gene expression
KW - proDynorphin
KW - proEnkephalin
KW - proOpiomelanocortin
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U2 - 10.1152/ajpregu.1996.270.5.r1019
DO - 10.1152/ajpregu.1996.270.5.r1019
M3 - Article
C2 - 8928900
AN - SCOPUS:0030001086
SN - 0363-6119
VL - 270
SP - R1019-R1024
JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
IS - 5 39-5
ER -