Metabolism and excretion of oestradiol-17beta and progesterone in the Sumatran rhinoceros (Dicerorhinus sumatrensis).
3H-labelled oestradiol-17beta and 14C-progesterone were injected i.v. into an adult female Sumatran rhinoceros (Dicerorhinus sumatrensis) and all urine and faeces collected over 4 days. Of the injected steroid, 68% of 3H-oestradiol and 89% of 14C-progesterone were recovered. Peak excretion in urine occurred on day 1 for both steroids, and for faeces on day 2 for 14C-progesterone, and between days 2 and 3 for 3H-oestradiol. Oestradiol metabolites were predominantly (nearly 70%) excreted into the urine, while progesterone metabolites were almost exclusively (> 99%) excreted into the faeces. The majority (> 70%) of urinary excreted oestrogens consisted of water-soluble (i.e., conjugated) forms, with > 90% of these being glucuronides. In contrast, > 75% of faecal oestrogen and progesterone metabolites were excreted as ether-soluble (i.e., unconjugated) forms. HPLC co-chromatography of oestrogens in hydrolysed urine indicated only one peak of radioactivity, co-eluting with authentic oestradiol-17beta, whereas two peaks of radioactivity were found after HPLC of faecal oestrogens, the major one co-eluting with oestrone and the less prominent one with oestradiol-17beta. Progesterone was excreted as numerous metabolites into the faeces. The three most abundant of these were identified using HPLC and gas chromatography mass spectrometry (GCMS) as 5beta-pregnane-3alpha,20alpha-diol, 5beta-pregnane-3alpha-ol-20-one, and a second pregnanediol, the exact structure of which could not be deduced. Measurement of urinary oestradiol-17beta and faecal immunoreactive pregnanediol and 5alpha-pregnane-3alpha-ol-20-one in daily samples enabled the first endocrine characterization of the ovarian cycle and indicated a cycle length of approximately 25 days.
Heistermann
M
M
Department of Reproductive Biology, German Primate Centre, Göttingen. mheiste@gwdg.de
Agil
M
M
Büthe
A
A
Hodges
J K
JK
D000818:Animals; D002250:Carbon Radioisotopes; D002851:Chromatography, High Pressure Liquid; D004958:Estradiol / Q000378:metabolism* / Q000652:urine; D004971:Estrus; D005243:Feces / Q000737:chemistry; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D005965:Glucuronates / Q000652:urine; D008297:Male; D010527:Perissodactyla / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism* / Q000652:urine; D014316:Tritium
D002250:Carbon Radioisotopes; D005965:Glucuronates; D014316:Tritium; D011374:Progesterone; D004958:Estradiol