RESUMEN
Smoking cessation increases body weight. The underlying mechanisms, however, have not been fully understood. We here report an establishment of a mouse model that exhibits an augmented body weight gain after nicotine withdrawal. High fat diet-fed mice were infused with nicotine for two weeks, and then with vehicle for another two weeks using osmotic minipumps. Body weight increased immediately after nicotine cessation and was significantly higher than that of mice continued on nicotine. Mice switched to vehicle consumed more food than nicotine-continued mice during the first week of cessation, while oxygen consumption was comparable. Elevated expression of orexigenic agouti-related peptide was observed in the hypothalamic appetite center. Pair-feeding experiment revealed that the accelerated weight gain after nicotine withdrawal is explained by enhanced energy intake. As a showcase of an efficacy of pharmacologic intervention, exendin-4 was administered and showed a potent suppression of energy intake and weight gain in mice withdrawn from nicotine. Our current model provides a unique platform for the investigation of the changes of energy regulation after smoking cessation.
Asunto(s)
Nicotina/efectos adversos , Síndrome de Abstinencia a Sustancias/patología , Aumento de Peso , Proteína Relacionada con Agouti/metabolismo , Animales , Calorimetría , Respiración de la Célula/efectos de los fármacos , Modelos Animales de Enfermedad , Ingestión de Energía/efectos de los fármacos , Exenatida/farmacología , Conducta Alimentaria/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Hipotálamo/metabolismo , Masculino , Ratones Endogámicos C57BL , ARN Mensajero/genética , ARN Mensajero/metabolismo , Síndrome de Abstinencia a Sustancias/genética , Aumento de Peso/efectos de los fármacos , Aumento de Peso/genéticaRESUMEN
A man in his 70s developed thyrotoxicosis due to painless thyroiditis after starting nivolumab, which was subsequently followed by severe hypothyroidism. We diagnosed him as chronic thyroiditis, initiated levothyroxine supplementation and treated appropriately. Retrospective CT images of the thyroid gland during the clinical course revealed that the CT attenuation value was high at first but gradually decreased. The high-density signal of the normal thyroid tissues reflects its function of concentrating inorganic iodine, and the progressive decrease of the CT density in the present case can be viewed as a reflection of the thyroid destruction and progressive loss of iodine during the clinical course of the development of chronic thyroiditis. Considering the high incidence rate of functional thyroid disease in patients treated with immune checkpoint inhibitors, CT density of the thyroid gland needs to be paid attention to as the first sign of thyroiditis in this patient population.