Department of Physiology, ICBS, Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500, Porto Alegre, RS, 90050-170, Brazil.
Physiol Behav. 2010 Apr 19;99(5):687-90. doi: 10.1016/j.physbeh.2010.02.002. Epub 2010 Feb 13.
Major depression is more prevalent among women than men, and progesterone might be involved in the mechanisms that generate these differences. Progesterone is clinically used for women in several reproductive events, but its antidepressant effect is unclear. Animal studies showed the interference of progesterone on depressive behaviors of rodents, but they are inconclusive, and no study compared different treatment durations. This study investigated the antidepressant effect of low doses of progesterone in male and female rats under acute or chronic administration. Male and female Wistar rats in different phases of the estrous cycle were acutely administered different doses of progesterone (0.0, 0.4. 0.8 and 1.2mg/kg) and tested in the forced swimming test (FST). The lowest dose of progesterone (0.4 mg/kg) was chronically administered during two complete estrous cycles and diestrous II female and male rats were tested in the FST. Progesterone decreased depressive-like behaviors only in chronically treated diestrous II female rats and increased immobility in male rats. This low dose of progesterone did not interfere in the hormonal cycling in female rats. Results also showed that diestrous II female rats had greater immobility than male rats in the FST. The greater immobility of diestrous II female rats shows that rats in this estrous phase present more depressive-like behaviors that may be associated with their lower serum levels of progesterone. We showed that progesterone chronically administered at low doses reverses these depressive-like behaviors and has an antidepressant effect during the diestrous II phase of the estrous cycle.
重度抑郁症在女性中的发病率高于男性，而孕激素可能参与了产生这些差异的机制。孕激素在临床上用于女性的几种生殖事件中，但它的抗抑郁作用尚不清楚。动物研究表明孕激素会干扰啮齿动物的抑郁行为，但结果并不明确，且没有研究比较不同的治疗持续时间。本研究在急性或慢性给药条件下，研究了低剂量孕激素对雄性和雌性大鼠的抗抑郁作用。在动情周期的不同阶段，雄性和雌性 Wistar 大鼠分别接受不同剂量的孕激素（0.0、0.4、0.8 和 1.2mg/kg）急性给药，并在强迫游泳试验（FST）中进行测试。最低剂量的孕激素（0.4mg/kg）在两个完整的动情周期和动情间期给药，并对动情间期的雌性和雄性大鼠进行 FST 测试。只有在慢性治疗的动情间期的雌性大鼠中，孕激素降低了类似抑郁的行为，并增加了雄性大鼠的不动性。这种低剂量的孕激素不会干扰雌性大鼠的激素循环。结果还表明，在 FST 中，动情间期的雌性大鼠比雄性大鼠的不动性更大。动情间期的雌性大鼠的更大不动性表明，这些动情期的大鼠表现出更多的类似抑郁的行为，这可能与其血清孕激素水平较低有关。我们表明，孕激素在动情间期以低剂量慢性给药可逆转这些类似抑郁的行为，并具有抗抑郁作用。
