Duffy Peter H, Lewis Sherry M, Mayhugh Martha A, Trotter Ronald W, Hass Bruce S, Latendresse John R, Thorn Brett T, Tobin Graham, Feuers Ritchie J
Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA.
Nutr Res. 2008 Jan;28(1):36-42. doi: 10.1016/j.nutres.2007.09.018.
The primary purpose of this study was to evaluate the effects of age and long-term dietary reduction on neoplastic diseases in rats fed the AIN-93M purified diet. Second, pathologic profiles are critical to comprehensive dietary evaluation. Male Sprague-Dawley rats assigned to 2 groups, ad libitum (AL) and dietary restricted (DR), were fed the AIN-93M (casein protein) diet free choice and reduced in amount by 31%, respectively. At 58 weeks of age, the predominant types of lesions in AL and DR rats were pituitary and skin tumors. At 114 weeks of age, the most common lesions were pituitary, adrenal gland, skin, mammary, brain, and pancreatic tumors and mononuclear cell leukemia. However, DR had no significant effect on these lesions. Primary findings demonstrate that DR significantly reduced the total number of tumors per rat and incidence of benign and primary tumors (all organs) but did not reduce the incidence of malignant tumors (all organs). Dietary restriction increased the percentage of unknown deaths. These results may explain why survival rates for AL and DR rats were not significantly different at 114 weeks (43.3 vs 57.5%, respectively). These findings differ from previous studies using NIH-31 cereal diet (Aging Clin Exp Res 2001;13:263; J Nutr 2002;132:101; Aging Clin Exp Res 2003;16(6):68; Aging Clin Exp Res 2004;16:448) where neoplastic lesions rather than nonneoplastic lesions were linked to a significant increase in survival rate among cohorts of DR-fed rats (J Nutr 2002;132:101). Factors such as diet composition and digestibility, although not independent of body weight, may have contributed to differences in rat mortality and may affect humans in a similar manner.
本研究的主要目的是评估年龄和长期饮食限制对食用AIN-93M纯化饮食的大鼠肿瘤性疾病的影响。其次，病理特征对于全面的饮食评估至关重要。将雄性Sprague-Dawley大鼠分为两组，即自由采食组（AL）和饮食限制组（DR），分别自由选择AIN-93M（酪蛋白）饮食和将摄入量减少31%。在58周龄时，AL组和DR组大鼠的主要病变类型为垂体和皮肤肿瘤。在114周龄时，最常见的病变是垂体、肾上腺、皮肤、乳腺、脑和胰腺肿瘤以及单核细胞白血病。然而，饮食限制对这些病变没有显著影响。主要研究结果表明，饮食限制显著降低了每只大鼠的肿瘤总数以及良性和原发性肿瘤（所有器官）的发生率，但并未降低恶性肿瘤（所有器官）的发生率。饮食限制增加了不明原因死亡的百分比。这些结果可能解释了为什么在114周时AL组和DR组大鼠的存活率没有显著差异（分别为43.3%和57.5%）。这些发现与之前使用NIH-31谷物饮食的研究不同（《衰老临床与实验研究》2001年；13:263；《营养学杂志》2002年；132:101；《衰老临床与实验研究》2003年；16(6):68；《衰老临床与实验研究》2004年；16:448），在那些研究中，肿瘤性病变而非非肿瘤性病变与饮食限制喂养的大鼠队列中存活率的显著提高有关（《营养学杂志》2002年；132:101）。饮食组成和消化率等因素虽然与体重并非无关，但可能导致了大鼠死亡率的差异，并且可能以类似的方式影响人类。
