Aihie Sayer A, Dunn R, Langley-Evans S, Cooper C
MRC Environmental Epidemiology Unit, Southampton General Hospital, University of Southampton, Southampton General Hospital, Southampton, UK.
Gerontology. 2001 Jan-Feb;47(1):9-14. doi: 10.1159/000052764.
Postweaning diet restriction is associated with prolongation of life span, reduced age-related disease and slower ageing. The effects of diet restriction imposed prior to weaning have not been so well characterised, but studies suggest an opposite effect with increased age-related diseases occurring in offspring exposed to undernutrition in prenatal life. It remains unclear whether life span is similarly adversely affected by early diet restriction.
The present study in rats aimed to evaluate the impact of a maternal low protein diet upon the life span of the resulting offspring.
Rat dams were fed either a 180-gram casein/kg control diet or a 90-gram casein/kg low protein diet from conception until the end of pregnancy. The offspring were then maintained with minimal handling until death from natural causes or distress-necessitated euthanasia.
The average life span of female rats exposed to low protein diets in utero was reduced by 11% (p = 0.044, Kaplan-Meier analysis). There was a similar but non- significant trend in the male offspring (control 76 +/- 3 weeks, low protein 73 +/- 3 weeks). In addition the rats exposed to a prenatal low protein diet had significantly higher systolic blood pressure at 4 weeks of age and tended to be smaller than control animals in postnatal life.
The results suggest that intrauterine diet restriction reduces life span in rats and contrasts with the well-recognised increase in life span produced by postweaning diet restriction. The timing of the nutritional intervention appears to be critical and recognition of this is relevant to understanding the mechanisms underlying the effects of diet restriction on ageing and life span.
断奶后饮食限制与寿命延长、年龄相关疾病减少及衰老减缓有关。断奶前实施饮食限制的影响尚未得到充分描述，但研究表明，产前营养不良的后代会出现相反的效果，即年龄相关疾病增加。目前尚不清楚早期饮食限制是否同样会对寿命产生不利影响。
本研究旨在评估母体低蛋白饮食对后代大鼠寿命的影响。
从受孕到妊娠结束，给大鼠母鼠喂食每千克含180克酪蛋白的对照饮食或每千克含90克酪蛋白的低蛋白饮食。然后尽量减少对后代的处理，直至其因自然原因死亡或因痛苦而必须实施安乐死。
子宫内暴露于低蛋白饮食的雌性大鼠平均寿命缩短了11%（p = 0.044，Kaplan-Meier分析）。雄性后代也有类似趋势，但无统计学意义（对照组76±3周，低蛋白组73±3周）。此外，产前暴露于低蛋白饮食的大鼠在4周龄时收缩压显著升高，且在出生后往往比对照动物体型小。
结果表明，子宫内饮食限制会缩短大鼠寿命，这与断奶后饮食限制可延长寿命这一公认观点形成对比。营养干预的时机似乎至关重要，认识到这一点有助于理解饮食限制对衰老和寿命影响的潜在机制。
