Laboratory of Endocrinology and Reproduction, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru.
Horm Metab Res. 2012 Feb;44(2):140-5. doi: 10.1055/s-0031-1301280. Epub 2012 Jan 24.
Men living at high altitudes in Peru compared to sea level counterparts have erythrocytosis (hemoglobin 16-21 g/dl) or excessive erythrocytosis (hemoglobin>21 g/dl). High testosterone (T) levels in men at high altitude (HA) were associated with excessive erythrocytosis. High androgen levels could be due to a low aromatase activity or to an elevated rate of conversion from precursors to testosterone. The aim of this study was to evaluate aromatase activity and rate of conversion from precursors to testosterone before and after administration of the aromatase enzyme inhibitor letrozole (5 mg/day) for a 5-day period to men at HA and at sea level (SL). The response to short term aromatase inhibition was assessed in 30 adult men living at sea level, 31 native men at HA with erythrocytosis (Hb 16-21 g/dl), and 35 men at HA with excessive erythrocytosis (Hb>21 g/dl). Serum hormone levels, estradiol/testosterone, testosterone/androstenedione, and testosterone/dehydroepiandrosterone sulfate (DHEAS) ratios were measured. Men with erythrocytosis had lower basal serum T/androstenedione ratios than men with excessive erythrocytosis at HA and men at sea level. Men at HA with excessive erythrocytosis had higher T/DHEAS ratios than men with erythrocytosis and than those at sea level before and after letrozole administration. After letrozole administration, both groups of men at high altitude (with erythrocytosis or with excessive erythrocytosis) showed lower aromatase activities than those at sea level. In conclusion, higher serum testosterone levels in men with excessive erythrocytosis were associated with an increased rate of conversion from DHEAS to testosterone rather than to a lower aromatase activity.
秘鲁高原地区的男性与海平面地区的男性相比，红细胞增多症（血红蛋白 16-21g/dl）或过度红细胞增多症（血红蛋白>21g/dl）的发生率更高。高原地区男性的高睾酮（T）水平与过度红细胞增多症有关。高雄激素水平可能是由于芳香化酶活性降低，也可能是前体向睾酮的转化率升高所致。本研究旨在评估高原地区和海平面地区男性在接受芳香化酶抑制剂来曲唑（5mg/天）治疗 5 天后，芳香化酶活性和前体向睾酮的转化率。我们评估了 30 名居住在海平面地区的成年男性、31 名高原地区红细胞增多症（Hb 16-21g/dl）男性和 35 名高原地区过度红细胞增多症（Hb>21g/dl）男性对短期芳香化酶抑制的反应。测量了血清激素水平、雌二醇/睾酮、睾酮/雄烯二酮和睾酮/脱氢表雄酮硫酸盐（DHEAS）比值。与高原地区过度红细胞增多症和海平面地区男性相比，高原地区红细胞增多症男性的基础血清 T/雄烯二酮比值较低。高原地区过度红细胞增多症男性的 T/DHEAS 比值高于红细胞增多症男性和海平面地区男性，且在来曲唑治疗前后均高于上述两者。来曲唑治疗后，高原地区红细胞增多症或过度红细胞增多症男性的芳香化酶活性均低于海平面地区男性。结论：过度红细胞增多症男性的血清睾酮水平较高与 DHEAS 向睾酮的转化率增加有关，而非芳香化酶活性降低。
