Absorption and metabolism of estrogens from the stomach and duodenum of pigs

Ruoff, W.L.; Dziuk, P. J.

doi:10.1016/0739-7240(94)90027-2

Cited by 24 publications

(23 citation statements)

References 27 publications

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“…Evidence is mounting that there are numerous interactions between estrogens and commonly used medications [7]. In fasted pigs E 2 appears to be metabolized in the stomach [8]. Foods may also change the way estrogens are absorbed and metabolized, as pre-and postmenopausal women who consume vegetarian diets have lower circulating E 2 levels after intravenous and oral E 2 administration [9].…”

Section: Discussionmentioning

confidence: 99%

Half-Life of Estradiol in Postmenopausal Women

Ginsburg¹,

Gao²,

Shea

et al. 1998

Gynecol Obstet Invest

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Estrogen replacement is often advised for postmenopausal women to prevent menopausal symptoms, osteoporosis and heart disease. However, little information is available concerning the half-life of estradiol (E₂) in postmenopausal women. This study was designed to determine the half-life and metabolism of transdermal E₂. A prospective clinical study of 8 healthy postmenopausal women was performed in the Clinical Research Center of the Brigham and Women’s Hospital. A transdermal E₂ patch 0.10 mg was placed on the abdominal wall. Thirteen hours later, after an overnight fast, the E₂ patch was removed and frequent blood sampling was performed over 6 h. Serum samples were assayed for E₂, estrone (E₁) and estrone sulfate (E₁S). Serum samples were taken before E₂ patch placement, for 30 min before patch removal, and for 6 h after patch removal. The basal E₂ level of women prior to use of transdermal E₂ was 19 ± 2 pg/ml (mean ± SE). Thirteen hours after transdermal E₂ placement, steady state levels had been reached, with a mean E₂ of 112 ± 6 pg/ml. The mean half-life of E₂ after removal of transdermal E₂ was 161 min (range 107–221 min). There was a direct relationship between the subjects’ weight and the half-life of E₂ (r = 0.79, p = 0.02). Mean basal E₁ levels were 23 ± 5 pg/ml and mean E₁ steady-state levels after E₂ patch placement were 39 ± 0.6 pg/ml. E₁S levels rose from mean basal levels of 1.5 ± 0.3 ng/ml to mean steady-state levels of 3.1 ± 0.1 ng/ml after placement of the E₂ patch. The apparent half-life of E₂ after discontinuing a transdermal E₂ patch is 2.7 h or 161 min.

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Section: Discussionmentioning

confidence: 99%

Half-Life of Estradiol in Postmenopausal Women

Ginsburg¹,

Gao²,

Shea

et al. 1998

Gynecol Obstet Invest

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“…In pigs, only 6% of orally administered estradiol is present as such in the portal vein, whereas the remainder is metabolized into estrone and glucuronide and sulfate conjugates of estradiol and estrone (18). Most of the portal estradiol is rapidly cleared into the systemic circulation (19).…”

Section: Discussionmentioning

confidence: 99%

Administration route-dependent effects of estrogens on IGF-I levels during fixed GH replacement in women with hypopituitarism

Klaauw

Biermasz

Zelissen

et al. 2007

European Journal of Endocrinology

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Objective: GH-deficient women using oral estradiol treatment require higher doses of recombinant human GH (rhGH) to achieve similar IGF-I levels when compared with men and women on transdermal estradiol replacement. The aim of this study was to evaluate the effects of oral versus transdermal estrogen administration at similar plasma estradiol levels on IGF-I, IGF-binding protein-3, and sex hormone-binding globulin (SHBG) concentrations. Design: Parallel crossover study in which two groups of hypogonadal and GH-deficient women with fixed and stable rhGH replacement passed through four different estradiol treatment schemes (2 and 4 mg oral, and 50 and 100 mg transdermal estradiol) with a duration of four cycles each to ensure a new steady state. Group I (18 patients using oral estradiol prior to the study) was treated with oral followed by transdermal estradiol and group II (five patients with transdermal estradiol prior to inclusion) with transdermal followed by oral estradiol. Results: Estradiol concentrations were lowest during 50 mg transdermal and highest during 4 mg oral estradiol treatment. Estradiol concentrations did not differ during 100 mg transdermal and 2 mg oral treatment. Nevertheless, IGF-I levels were significantly higher during 100 mg transdermal when compared with 2 mg oral treatment (PZ0.005 in group I and 0.02 in group II), while SHBG levels were significantly lower (PZ0.002 in group I and PZ0.004 in group II). SHBG and IGF-I concentrations were negatively correlated (RZK0.41, PZ0.0001). Conclusion: During fixed GH replacement, the route of estrogen administration is a determinant of IGF-I levels in hypogonadal GH-deficient women.European Journal of Endocrinology 157 709-716

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“…These conjugates can enter the bile and be delivered to the small intestine, where they can be deconjugated by the intestinal bacteria to produce the free steroids, which are absorbed into the portal venous blood from the enterocytes; this is known as the enterohepatic circulation (Roberts et al, 2002). Ruoff and Dziuk (1994) showed that oestradiol placed in the stomach of pigs undergoes enterohepatic circulation. Treatment with oral antibiotics to decrease the activity of the gut microbes interrupted the enterohepatic circulation by decreasing the amount of deconjugation and reducing the reabsorption of estrogens (Ruoff and Dziuk, 1994).…”

Section: Introductionmentioning

confidence: 99%

“…Ruoff and Dziuk (1994) showed that oestradiol placed in the stomach of pigs undergoes enterohepatic circulation. Treatment with oral antibiotics to decrease the activity of the gut microbes interrupted the enterohepatic circulation by decreasing the amount of deconjugation and reducing the reabsorption of estrogens (Ruoff and Dziuk, 1994). Although it is not known whether AND undergoes enterohepatic circulation, showed that hepatocytes produce sulphoconjugates and glucuronyl conjugates of AND; also found that increased levels of sulphoconjugation decreased the accumulation of AND in adipose tissue.…”

Section: Introductionmentioning

confidence: 99%

Efficacy of non-nutritive sorbent materials as intestinal-binding agents for the control of boar taint

Jen

Squires

2011

Animal

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In many countries, male pigs are castrated to prevent boar taint, but this practice raises concerns about animal welfare and reduces the production efficiency of pork. The objective of this study was to develop dietary manipulations to prevent boar taint. We evaluated the effectiveness of adding activated carbon (AC) or Tween-60 (Tween; polyoxyethylene sorbitan monostearate) to pig finishing diets to reduce levels of androstenone (AND) and skatole in plasma and fat of entire male pigs. Boars (159 6 2 days of age at the start of the experiment) were fed diets supplemented with either 5% AC or 5% Tween for 28 days followed by either 14 or 28 days of recovery. Plasma samples were collected at experimental days 0, 7, 14, 21, 28, 42 and 56, and backfat biopsies were taken at experimental days 0, 28, 42 and 56. Feeding AC significantly (P , 0.05) reduced the levels of AND in plasma by day 28 compared to day 0 and by day 42 in fat compared to day 0. AC treatment also decreased levels of oestrone sulphate (E 1 S) in plasma by day 7 compared to day 0. Treatment with Tween significantly decreased (P , 0.05) the levels of plasma AND by day 28 from levels at day 0. Tween treatment did not significantly affect levels of fat AND or plasma E 1 S compared to day 0; however, fat AND levels decreased between days 28 and 42 following treatment with Tween (P , 0.05). Levels of plasma E 1 S, plasma AND and fat AND for control boars remained constant throughout the experiment. Skatole plasma concentrations were very low and did not vary significantly (P . 0.05) from day 0 for any treatment, but fat skatole levels decreased by day 42 in the Tween treatment group. Importantly, there was no difference in growth rate between the control and experimental groups. We conclude that adding AC or Tween to finishing diets for boars can reduce the levels of plasma and fat AND, but further work is needed to confirm the effects of these treatments on reducing fat skatole levels.

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Absorption and metabolism of estrogens from the stomach and duodenum of pigs

Cited by 24 publications

References 27 publications

Half-Life of Estradiol in Postmenopausal Women

Half-Life of Estradiol in Postmenopausal Women

Administration route-dependent effects of estrogens on IGF-I levels during fixed GH replacement in women with hypopituitarism

Efficacy of non-nutritive sorbent materials as intestinal-binding agents for the control of boar taint

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