Characterization of the onset of leptin effects on the regulation of energy balance

Abstract

Leptin is a hormone required for the regulation of body weight in adult animals. However, during postnatal period, leptin is mostly involved in developmental processes. Because the precise moment in which leptin starts to exert its metabolic effects is not well characterized, our objective was to identify the approximate onset of leptin effects on the regulation of energy balance. We observed that male Lepob/ob mice started to exhibit increased body fat mass from postnatal day 13 (P13), whereas in females the increase in adiposity began on P20. Daily leptin injections from P10 to P22 did not reduce the weight gain of wild-type mice. However, an acute leptin injection induced an anorexigenic response in 10-day-old C57BL/6 mice, but not in 7-day-old mice. An age-dependent increase in the number of leptin receptor-expressing neurons and leptin-induced pSTAT3 cells was observed in the hypothalamus of P7, P10 and P16 mice. Leptin deficiency started to modulate the hypothalamic expression of transcripts involved in the regulation of metabolism between P7 and P12. Additionally, fasting-induced hypothalamic responses were prevented by leptin replacement in 10-day-old mice. Finally, 12-day-old males and females showed similar developmental timing of axonal projections of arcuate nucleus neurons in both wild-type and Lepob/ob mice. In summary, we provided a detailed characterization of the onset of leptin’s effects on the regulation of energy balance. These findings contribute to the understanding of leptin functions during development.

The Role of Molecular and Hormonal Factors in Obesity and the Effects of Physical Activity in Children

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Roles of leptin on energy balance and thermoregulation in Eothenomys miletus

“…Leptin can regulate animal food intake (Campfield et al, 1995;Baicy et al, 2007;Fischer et al, 2016), and energy balance (Friedman 2019;Teixeira et al, 2021). Moreover, some studies have shown that leptin also plays an important role in thermoregulation (Luheshi et al, 1999;Fischer et al, 2016;Weiner et al, 2021).…”