TY - JOUR
T1 - Glucose relays information regarding nutritional status to the neural circuits that control the somatotropic, corticotropic, and gonadotropic axes in adult male rhesus macaques
AU - Lado-Abeal, Joaquin
AU - Veldhuis, Johannes D.
AU - Norman, Reid L.
PY - 2002
Y1 - 2002
N2 - In male mammals, the neuroendocrine responses to fasting include increased GH and cortisol secretion and suppressed LH and T levels. Because blood glucose levels fall during fasting, we hypothesized that this modest, but consistent, change in blood glucose was a metabolic signal for the neuroendocrine adjustments of reproductive and metabolic hormones. Glucose (D-dextrose, 480 kcal/d) was infused into fasted (48 h) adult male rhesus macaques; and LH, cortisol, and GH were measured in plasma from samples collected at 15-min intervals for the last 15 h of the fast. We analyzed hormone secretion by deconvolution analysis, and the orderliness of release patterns by the approximate entropy statistic. Circulating blood glucose was 76 ± 7 mg/dl in the fed control group, significantly higher (P < 0.01) than the level of 56 ± 3 mg/dl in the fasted group. The increase in GH pulsatility and the 2-fold elevation in cortisol levels observed in the fasted male macaques were prevented by parenteral glucose delivery. The suppression of LH in fasted animals was not relieved by glucose infusions but seemed to be partially prevented in three of the animals. These findings are consistent with the hypothesis that glucose serves as a signal of nutritional status controlling adaptive neuroendocrine responses to fasting in the primate.
AB - In male mammals, the neuroendocrine responses to fasting include increased GH and cortisol secretion and suppressed LH and T levels. Because blood glucose levels fall during fasting, we hypothesized that this modest, but consistent, change in blood glucose was a metabolic signal for the neuroendocrine adjustments of reproductive and metabolic hormones. Glucose (D-dextrose, 480 kcal/d) was infused into fasted (48 h) adult male rhesus macaques; and LH, cortisol, and GH were measured in plasma from samples collected at 15-min intervals for the last 15 h of the fast. We analyzed hormone secretion by deconvolution analysis, and the orderliness of release patterns by the approximate entropy statistic. Circulating blood glucose was 76 ± 7 mg/dl in the fed control group, significantly higher (P < 0.01) than the level of 56 ± 3 mg/dl in the fasted group. The increase in GH pulsatility and the 2-fold elevation in cortisol levels observed in the fasted male macaques were prevented by parenteral glucose delivery. The suppression of LH in fasted animals was not relieved by glucose infusions but seemed to be partially prevented in three of the animals. These findings are consistent with the hypothesis that glucose serves as a signal of nutritional status controlling adaptive neuroendocrine responses to fasting in the primate.
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U2 - 10.1210/endo.143.2.8548
DO - 10.1210/endo.143.2.8548
M3 - Article
C2 - 11796492
AN - SCOPUS:0036157668
SN - 0013-7227
VL - 143
SP - 403
EP - 410
JO - Endocrinology
JF - Endocrinology
IS - 2
ER -