Given an abstract from a research paper, your task is to identify and label relationships between chemical compounds and genes mentioned in the abstract.

The relationship type must be one of ['DOWNREGULATOR', 'SUBSTRATE', 'INDIRECT-REGULATOR', 'PART-OF', 'MODULATOR-ACTIVATOR', 'REGULATOR', 'INHIBITOR', 'COFACTOR', 'UPREGULATOR', 'ACTIVATOR', 'ANTAGONIST', 'NOT', 'INDIRECT-DOWNREGULATOR', 'SUBSTRATE_PRODUCT-OF', 'INDIRECT-UPREGULATOR', 'AGONIST', 'PRODUCT-OF', 'MODULATOR', 'DIRECT-REGULATOR', 'UNDEFINED', 'AGONIST-INHIBITOR', 'AGONIST-ACTIVATOR', 'MODULATOR-INHIBITOR'].

Please format your output as a JSON array. Each entry in the array should express a single relation, formatted as ["<Entity_A>", "<RELATION_A_B>", "<Entity_B>"]. If no relations can be found, please output an empty JSON array [].

Abstract:

Hyperphagia alters expression of hypothalamic 5-HT2C and 5-HT1B receptor genes and plasma des-acyl ghrelin levels in Ay mice. The central melanocortin (MC) pathway is suggested to mediate satiety signaling downstream of serotonin (5-HT) 2C receptors. 5-HT2C receptor mutant mice consume more food, which leads to late-onset obesity and impaired glucose tolerance. Ay mice with ectopic expression of the agouti peptide, which leads to a perturbation of the central MC pathway, develop obesity and diabetes, associated with low levels of plasma total ghrelin. Here, we report that 5-wk-old Ay mice consumed more food in association with decreases in levels of plasma des-acyl ghrelin, but not active ghrelin, and increases in hypothalamic 5-HT2C and 5-HT1B receptor gene expression compared with wild-type mice matched for age and body weight. These alterations were also observed in 8-wk-old obese Ay mice. Restricted feeding significantly decreased hypothalamic 5-HT2C and 5-HT1B receptor gene expression in association with a reversal of the decreases in plasma des-acyl ghrelin levels in 5-wk-old Ay mice. Moreover, restricted feeding reduced body weight, hyperinsulinemia, and hyperglycemia in association with increases in plasma des-acyl ghrelin levels in 8-wk-old obese Ay mice. Administration of m-chlorophenylpiperazine and fenfluramine, both of which induce anorexic effects via 5-HT2C receptors and/or 5-HT1B receptors, suppressed food intake in 5- and 8-wk-old Ay mice, whereas the anorexic effects were attenuated in food-restricted Ay mice. These findings suggest that the agouti peptide down-regulates hypothalamic 5-HT2C and 5-HT1B receptor gene expression under restricted feeding conditions, whereas chronic hyperphagia increases the expression of these genes and decreases plasma des-acyl ghrelin levels in Ay mice.
[["fenfluramine", "REGULATOR", "5-HT1B"], ["fenfluramine", "REGULATOR", "5-HT2C"], ["m-chlorophenylpiperazine", "REGULATOR", "5-HT2C"], ["m-chlorophenylpiperazine", "REGULATOR", "5-HT1B"]]