Martins Paulo José Forcina, Galdieri Luciano Camargo, Souza Fernanda Gonçalves, Andersen Monica Levy, Benedito-Silva Ana Amélia, Tufik Sergio, D'Almeida Vânia
Department of Psychobiology-Universidade Federal de São Paulo, Rua Napoleão de Barros, 925-3rd floor (room 1), CEP 04024-002, São Paulo-SP, Brazil.
Life Sci. 2005 Apr 15;76(22):2621-9. doi: 10.1016/j.lfs.2004.12.011.
Hyperhomocysteinemia was initially related to cardiovascular diseases; but homocysteine (Hcy) metabolism disturbances have more recently associated with a wide range of pathophysiological conditions including age-related diseases, disrupted circadian rhythms and gynaecological disorders. Since in many cases we do not know to what extent animal models are physiologically similar to human ones, this study aimed to track spontaneous variations in rat plasma Hcy concentrations during different physiological processes such as life cycle, 24 hours and estrous cycle. Plasma total Hcy concentrations were accessed by HPLC. Plasma Hcy concentration varied with age and newborns had the lowest values (2.94 +/- 0.47 micromol/L). Rats aged 10 days presented concentration similar to 3 month old animals (6.87 +/- 0.67 and 8.29 +/- 1.55 micromol/L respectively). Values decreased to 6.42 +/- 1.65 micromol/L at 6 months and 4.87 +/- 0.81 micromol/L at 28 months. Concerning circadian variations in Hcy concentration cosinor analysis showed acrophase in young rats at 1:09 pm, but no plasma Hcy circadian variations in aged rats. Female rats showed changes in Hcy concentration during the estrous cycle with higher values during the diestrous I (10.61 +/- 1.81 micromol/L) compared with the estrous (8.47 +/- 1.86 micromol/L) and diestrous II (7.68 +/- 1.58 micromol/L) phases. In conclusion, plasma Hcy concentration varied spontaneously with ontogenic development and during the estrous cycle and presented a circadian rhythm variation in young rats.
高同型半胱氨酸血症最初与心血管疾病相关；但最近同型半胱氨酸（Hcy）代谢紊乱与多种病理生理状况有关，包括与年龄相关的疾病、昼夜节律紊乱和妇科疾病。由于在许多情况下我们并不清楚动物模型在生理上与人类模型的相似程度，本研究旨在追踪大鼠血浆Hcy浓度在不同生理过程（如生命周期、24小时和发情周期）中的自发变化。通过高效液相色谱法测定血浆总Hcy浓度。血浆Hcy浓度随年龄变化，新生儿的值最低（2.94±0.47微摩尔/升）。10日龄大鼠的浓度与3月龄动物相似（分别为6.87±0.67和8.29±1.55微摩尔/升）。6月龄时降至6.42±1.65微摩尔/升，28月龄时降至4.87±0.81微摩尔/升。关于Hcy浓度的昼夜变化，余弦分析显示幼鼠的高峰相位在下午1:09，但老年大鼠血浆Hcy无昼夜变化。雌性大鼠在发情周期中Hcy浓度有变化，动情间期I期（10.61±1.81微摩尔/升）的值高于发情期（8.47±1.86微摩尔/升）和动情间期II期（- 7.68±1.58微摩尔/升）。总之，血浆Hcy浓度随个体发育和发情周期自发变化，幼鼠呈现昼夜节律变化。
