| pubmed-article:2355734 | pubmed:abstractText | In order to measure the interconversions of estrone (E1) and estradiol (E2) and their conversion to the 16 alpha-hydroxylated estrogens, 16 alpha-hydroxy estrone (16 alpha-OHE1) and estriol (E3), we infused 11 female rhesus monkeys with [3H]E2 and [14C]E1 and measured radioactivity in the blood as E1, E2 and 16 alpha-OHE1 (n = 9) and in the urine as the glucuronides of E1, E2, 16 alpha-OHE1, and E3 (n = 11). The mean conversion of E1 to E2 as measured in blood (percent of infused E1 measured in blood as E2, [rho]1.2BB) was 29.2 +/- 1.6% and as measured in the urine of the same animals, [rho]1.2BM, was 77.4 +/- 5.9%. The mean conversion of E2 to E1, [rho]2.1BB was 21.5 +/- 1.0% and as measured in urine, [rho]2.1BM was 67.7 +/- 4.6%. Thus for both estrone and estradiol only 30-35% of the interconversions occurred in pools which were in equilibrium with the blood pool of these estrogens. The remaining 65-70% occurred in a pool, probably liver, in which glucuronidation occurred immediately after conversion. The conversion ratios (the ratio of the concentration in the blood of radioactivity as 16 alpha-OHE1 to its precursor, CRPrec,16 alpha-OHE1) was 0.036 +/- 0.008 for CRE1,16 alpha-OHE1 and 0.0039 +/- 0.0010 for CRE2,16 alpha-OHE1. The percentages of administered E1 excreted in the urine as the glucuronides of E1, E2, 16 alpha-OHE1 and E3 were 20.1 +/- 1.5, 1.6 +/- 0.2, 0.96 +/- 0.20 and 0.76 +/- 0.07 respectively. The percentages of administered E2 excreted in the urine as E1, E2, 16 alpha-OHE1 and E3 were 14.4 +/- 1.0, 2.2 +/- 0.3, 0.57 +/- 0.05 and 0.68 +/- 0.11 respectively. Thus there are minor differences in the patterns of excreted metabolites of E1 and E2. Furthermore, 16 alpha-OHE1 and E3 are not major metabolites of E1 or E2 in the female rhesus monkey. | lld:pubmed |
