Adrenal steroids as parameters of the bioavailability of MA and MPA

Willemse, Pax H.B.; Dikkeschei, L. D.; Tjabbes, Tonnis; Veelen, H. van; Sleijfer, Dirk

doi:10.1016/0277-5379(90)90234-k

Cited by 13 publications

(10 citation statements)

References 12 publications

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“…Suppression of the HPA axis was thus expected during MPA treatment, as was reported in both humans [52] and dogs [16,53]. Indeed, we found the cortisol response to stimulation to be decreased with MPA treatment, although ACTH secretion was only slightly affected, possible because MPA affects the HPA axis for only 2-3 weeks [53].…”

Section: Discussionsupporting

confidence: 78%

Adenohypophyseal function in bitches treated with medroxyprogesterone acetate

Beijerink

Bhatti

Okkens

et al. 2007

Domestic Animal Endocrinology

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The aim of this study was to investigate the effects of treatment with medroxyprogesterone acetate (MPA) on canine adenohypophyseal function. Five Beagle bitches were treated with MPA (10 mg/kg, every 4 weeks) and their adenohypophyseal function was assessed in a combined adenohypophyseal function test. Four hypophysiotropic hormones (CRH, GHRH, GnRH, and TRH) were administered before and 2, 5, 8, and 11 months after the start of MPA treatment, and blood samples for determination of the plasma concentrations of ACTH, cortisol, GH, IGF-1, LH, FSH, prolactin, ␣-MSH, and TSH were collected at −15, 0, 5, 10, 20, 30, and 45 min after suprapituitary stimulation.MPA successfully prevented the occurrence of estrus, ovulation, and a subsequent luteal phase. MPA treatment did not affect basal and GnRH-induced plasma LH concentrations. The basal plasma FSH concentration was significantly higher at 2 months after the start of MPA treatment than before or at 5, 8, and 11 months after the start of treatment. The maximal FSH increment and the AUC for N.J. Beijerink et al. / Domestic Animal Endocrinology xxx (2006) xxx-xxxmonths of MPA treatment. Differences in mean basal plasma GH concentrations before and during treatment were not significant, but MPA treatment resulted in significantly elevated basal plasma IGF-1 concentrations at 8 and 11 months. MPA treatment did not affect basal and stimulated plasma ACTH concentrations, with the exception of a decreased AUC for ACTH at 11 months. In contrast, the maximal cortisol increment and the AUC for cortisol after suprapituitary stimulation were significantly lower during MPA treatment than prior to treatment. MPA treatment did not affect basal plasma concentrations of prolactin, TSH, and ␣-MSH, with the exception of slightly increased basal plasma TSH concentrations at 8 months of treatment. MPA treatment did not affect TRH-induced plasma concentrations of prolactin and TSH.In conclusion, the effects of chronic MPA treatment on adenohypophyseal function included increased FSH secretion, unaffected LH secretion, activation of the mammary GH-induced IGF-I secretion, slightly activated TSH secretion, suppression of the hypothalamic-pituitary-adrenocortical axis, and unaffected secretion of prolactin and ␣-MSH.

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Section: Discussionsupporting

confidence: 78%

Adenohypophyseal function in bitches treated with medroxyprogesterone acetate

Beijerink

Bhatti

Okkens

et al. 2007

Domestic Animal Endocrinology

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“…Endocrine inhibition of the pituitary-adrenal system has been suggested as one of the mechanisms of action of MPA [24], and an inverse correlation between serum concentrations of MPA and plasma cortisol levels has been reported [25, 26]. Plasma cortisol levels decreased in almost all patients in the present study, reflecting a remarkable influence of MPA administration.…”

Section: Discussionsupporting

confidence: 53%

A Randomized Controlled Comparative Study of Oral Medroxyprogesterone Acetate 1,200 and 600 mg in Patients with Advanced or Recurrent Breast Cancer

Koyama

Tominaga²,

Asaishi³

et al. 1999

Oncology

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A randomized controlled comparative study of oral medroxyprogesterone acetate (MPA) 1,200 mg (arm I) and 600 mg (arm II) was conducted in 80 patients with advanced or recurrent breast cancer. There were no significant differences between arm I and arm II in terms of response rate, duration of response and survival, or in terms of incidence and severity of adverse reactions. The lowest serum MPA concentration in responders tended to be higher than that in nonresponders. In the cohort of this study, the lowest concentration in partial response was 17.4 ng/ml, suggesting that this level may be the required minimum serum concentration.

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“…Another explanation for the high dose progestin-induced inhibition of tumour progression is the fact that many synthetic progestins used for breast cancer treatment have intrinsic androgenic and glucocorticoid activities [42,43]. Due to this glucocorticoid activity progestin treatment results in suppression of plasma cortisol concentrations in humans [44,45], dogs [46][47][48] and cats [49,50] and reduces the plasma concentrations of sex steroids in postmenopausal breast cancer patients [51][52][53]. In vitro progestins inhibit the biosynthesis of DHP and estradiol in rat granulosa cells [54,55] and of estradiol in breast cancer cell lines [56].…”

Section: Discussionmentioning

confidence: 99%