Life Sciences Faculty, Bar Ilan University, Ramat Gan, Israel.
Horm Behav. 2010 Nov;58(5):844-53. doi: 10.1016/j.yhbeh.2010.08.008. Epub 2010 Aug 22.
Obesity and the metabolic syndrome represent serious health threats affecting increasing numbers of individuals, with females being more affected than males and with growing incidence among children and adolescents. In the present study, we used the OLETF rat model of early-onset obesity to examine the influence of different timing of food restriction on long-term obesity levels in females. Food restriction took place at different time windows: from weaning until postnatal day (PND) 45 (early); from weaning until PND90 (chronic); or from PND45 until PND70 (late). Follow-up continued until PND90. During and after the termination of the diet-restriction period, we focused on peripheral adiposity-related measures such as fat pad weight (brown, retroperitoneal and inguinal); inguinal adipocyte size and number; and leptin, oxytocin and glucose levels. We also examined body weight, feeding efficiency, spontaneous intake after release from diet-restriction, and plasma creatinine levels and estrous cycle characteristics as a result of the chronic diet. The results suggest that while food restriction produced significant weight and adiposity loss, OLETF females presented poor weight loss retention after the early and late short-term diets. The estrous cycle structure and time of first estrous of the OLETF rats were normalized by chronic food restriction. Females responded to early food restriction in a different manner than males did in previous studies, further emphasizing the importance of sex-appropriate approaches in the investigation and treatment of the pathologies related to obesity and the metabolic syndrome.
肥胖和代谢综合征是严重的健康威胁，影响着越来越多的人群，女性比男性更容易受到影响，且儿童和青少年的发病率也在不断上升。在本研究中，我们使用 OLETF 大鼠肥胖早期发病模型，研究了不同时期的食物限制对雌性肥胖长期水平的影响。食物限制发生在不同的时间窗口：从断奶到出生后第 45 天（早期）；从断奶到出生后第 90 天（慢性）；或从出生后第 45 天到第 70 天（晚期）。随访持续到出生后第 90 天。在饮食限制期间和之后，我们关注了与外周脂肪相关的测量指标，如脂肪垫重量（棕色、腹膜后和腹股沟）；腹股沟脂肪细胞大小和数量；以及瘦素、催产素和血糖水平。我们还检查了体重、进食效率、限制饮食后自发摄入、血浆肌酐水平和发情周期特征，作为慢性饮食的结果。结果表明，尽管食物限制导致体重和肥胖明显减轻，但 OLETF 雌性大鼠在早期和晚期短期饮食后体重减轻的保留效果较差。慢性食物限制使 OLETF 大鼠的发情周期结构和首次发情时间正常化。雌性动物对早期食物限制的反应与之前研究中的雄性动物不同，这进一步强调了在肥胖和代谢综合征相关病理的研究和治疗中采用性别适当方法的重要性。
