Table 1.
Soy isoflavone and metabolite concentrations (normalized to creatinine content) in pooled urine samples collected from dogs (n= 10) and cats (n= 18) fed a soy-based diet. Samples were also assayed for dehydroequol, O-desmethylangolensin, and 6-hydroxy-O-desmethylangolensin but these metabolites were not detected. Results are presented as the mean and standard deviation (SD) of quadruplicate measurements of pooled dog (n=10) and cat (n=18) urine samples.
| Urinary concentration (pmoles / mg creatinine) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Genistein | Daidzein | Glycitein | Dihydrogenistein | Dihydrodaidzein | Equol | |||||||
| Mean | (SD) | Mean | (SD) | Mean | (SD) | Mean | (SD) | Mean | (SD) | Mean | (SD) | |
| Dog urine (n = 10) | ||||||||||||
| Unconjugated(a) | 31 | (7) | 20 | (5) | 9 | (1) | 0 | (0) | 60 | (12) | 0 | (0) |
| Conjugated(b) | 1025 | (273) | 1099 | (344) | 573 | (192) | 1919 | (487) | 822 | (263) | 1.2 | (0.9) |
| Total(c) | 1056 | (257) | 1119 | (305) | 582 | (143) | 1919 | (487) | 883 | (229) | 1.2 | (0.9) |
| Glucuronides(d) | 530 | (129) | 587 | (118) | 312 | (55) | 631 | (146) | 259 | (39) | 0.5 | (0.3) |
| % Glucuronides(e) | 50 | (12) | 52 | (12) | 54 | (11) | 33 | (8) | 29 | (6) | 39 | (27) |
| Cat urine (n = 18) | ||||||||||||
| Unconjugated(a) | 29 | (21) | 37 | (4) | 10 | (1) | 0 | (0) | 0 | (0) | 0 | (0) |
| Conjugated(b) | 3431 | (202) | 1442 | (133) | 140 | (11) | 2998 | (363) | 278 | (57) | 190 | 23 |
| Total(c) | 3460 | (1371) | 1478 | (153) | 150 | (16) | 2998 | (363) | 278 | (57) | 190 | 23 |
| Glucuronides(d) | 11 | (2) | 168 | (20) | 55 | (10) | 0 | (0) | 0 | (0) | 0 | (0) |
| % Glucuronides(e) | 0.3 | (0.1) | 11 | (1) | 37 | (5) | 0 | (0) | 0 | (0) | 0 | (0) |
(a)
Concentrations without enzyme treatment
(b)
Concentrations after treatment with Helix pomatia glucuronidase/sulfatase enzymes
(c)
Sum of free and conjugated concentrations
(d)
Concentrations after treatment with bovine liver β-glucuronidase
(e)
Percentage of free and conjugated isoflavones that are glucuronide