Dambrova Maija, Cirule Helena, Svalbe Baiba, Zvejniece Liga, Pugovichs Osvalds, Zorenko Tatjana, Kalvinsh Ivars, Liepinsh Edgars, Belozertseva Irina
Latvian Institute of Organic Synthesis, Aizkraukles St. 21, Riga, LV-1006, Latvia.
Physiol Behav. 2008 Oct 20;95(3):341-7. doi: 10.1016/j.physbeh.2008.06.012. Epub 2008 Jun 29.
l-carnitine has a documented role as a cofactor in cellular energy metabolism and fatty acid beta-oxidation pathways and it has also been considered to function in reproductive biology. We investigated whether decreasing concentrations of L-carnitine using an inhibitor of its biosynthesis, mildronate (3-(2,2,2-trimethylhydrazinium)-propionate), would influence the sexual behavior or sperm quality in male rats. Mildronate treatment induced a significant decrease in carnitine concentration and an increase in gamma-butyrobetaine (GBB) concentration in both plasma and testes extracts. However, the expression of carnitine palmitoyltransferase I in testes and testosterone concentration in plasma was not changed in mildronate treated rat. Behavioral experiments demonstrated that mildronate treatment did not decrease the sexual motivation in both sexually naive and sexually experienced rats. The densities of spermatozoa in the cauda epididymis, as well as motility, were unchanged after mildronate treatment at a dose of 100 mg/kg. In conclusion, our study provides experimental evidence that mildronate induces decrease in the free carnitine concentration in rat testes, but does not decrease the sexual activity or sperm quality of male rats.
左旋肉碱在细胞能量代谢和脂肪酸β氧化途径中作为辅助因子已有文献记载，并且它也被认为在生殖生物学中发挥作用。我们研究了使用其生物合成抑制剂米屈肼（3-(2,2,2-三甲基肼基)丙酸酯）降低左旋肉碱浓度是否会影响雄性大鼠的性行为或精子质量。米屈肼处理导致血浆和睾丸提取物中肉碱浓度显著降低，γ-丁基甜菜碱（GBB）浓度升高。然而，米屈肼处理的大鼠睾丸中肉碱棕榈酰转移酶I的表达和血浆中睾酮浓度没有变化。行为实验表明，米屈肼处理并未降低性幼稚和有性经验大鼠的性动机。剂量为100mg/kg的米屈肼处理后，附睾尾部精子密度以及活力均未改变。总之，我们的研究提供了实验证据，表明米屈肼会导致大鼠睾丸中游离肉碱浓度降低，但不会降低雄性大鼠的性活动或精子质量。
