3H-乙炔雌二醇环戊醚的吸收、分布和排泄

给雌大鼠口服氚标记的乙炔雌二醇环戊醚(EECPE)后半小时血液中即可测出放射性,但10小时后才达高峰。在胃肠道的生物半衰期为13小时,说明³H-EECPE的吸收较慢。猴服³H-EECPE后1小时血液即可测出放射性,4小时达高峰。³H-EECPE被吸收后,在大鼠和猴体内的分布均以脂肪组织的浓度最高,脑组织的浓度也较高,而在靶器官—子宫、输卵管、乳腺—的浓度却不高。³H-EECPE在各组织中均有较长时间的储留,尤其在脂肪组织中储留的时间更长,这可以解释其口服后的长效作用。³H-EECPE的主要排泄途径为粪,自尿排出较少。由于在体内储留,所以排泄缓慢。

PHYSIOLOGICAL DISPOSITION OF 3H-QUINESTROL

The absorption, distribution and excretion of ³H-quinestrol (³H-EECPE), labelled at C-9 and C-11, were studied in female rats and two rhesus monkeys. The absorption of ³H-EECPE from the gastrointestinal tract was a relatively slow process, as evidenced by the finding that the biological half life of ³H-EECPE in the gastrointestinal tract was 13 hours. Radioactivity was detectable in the blood of rats 30 minutes after oral administration, However, the radioactivity did not rise to its peak level until 10 hours after administration. In one monkey radioactivity was detected one hour after oral administration of ³H-EECPE and rose to its peak level in 4 hours. After absorption of ³H-EECPE, radioactivity was found to be highest in the fat tissues and fairly high in the brain, while in the target organs (uterus, oviduct and breast)radioactivity was rather low ³E-EECPE seemed to be stored for long periods of time in various tissues after absorption as shown by the sustained radioactivity in these tissues. This was especially so with the fat tissue as could be exemplified by the detection of fairly high radioactivity in the fat tissue of a monkey 21 days after administration of ³H-EECPE. ³H-EECPE was excreted mainly by the fecal route, while the renal route of excretion was of less importance. AS a consequence of prolonged storage in the body tissues, clearance of ³H-EECPE from the body was relatively slow. The amount of radioactive material excreted in the feces and urine 15 days after oral adminidtration of ³H-EECPE to rats was 34.1% of the amount ingested and that excreted by a monkey three weeks after administration was 53.8% of the dose.