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Henriquez S, Tapia A, Quezada M, Vargas M, Cardenas H, Rios M, Salvatierra AM, Croxatto H, Orihuela P, Zegers-Hochschild F, Munroe DJ, Velasquez L. Deficient expression of monoamine oxidase A in the endometrium is associated with implantation failure in women participating as recipients in oocyte donation. Mol Hum Reprod 2006; 12:749-54. [PMID: 17020906 DOI: 10.1093/molehr/gal082] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Successful implantation depends both on the quality of the embryo and on the endometrial receptivity. The latter depends on progesterone-induced changes in gene expression, a process that has been characterized by microarray analysis. One of the genes whose transcription appears to be enhanced during the receptive period is monoamine oxidase A (MAO-A). Our first objective was to confirm the increased expression of MAO-A in the endometrium during the receptive phase of spontaneous normal cycles using real time PCR and immunofluorescence. The second objective was to examine the endometrial expression of MAO-A during the receptive phase induced by exogenous estradiol (E(2)) and progesterone in patients whose endometrium was shown to have been either receptive or non-receptive to embryo implantation in repeated cycles of oocyte donation. Results showed that MAO-A transcript levels increased between the pre-receptive (LH+3) and receptive phase (LH+7) in all spontaneous cycles examined, with a median increase of 25-fold. Immunofluorescent labelling demonstrated MAO-A localization to the glandular and luminal epithelium with an increasing positive score between LH+3 and LH+7. Conversely, prior failure of embryo implantation was associated with a 29-fold decrease in MAO-A mRNA levels and a substantial reduction in MAO-A protein immunofluorescent label score. These results show a strong association between endometrial receptivity and MAO-A expression in the endometrial epithelium, suggesting an important role for this enzyme in normal implantation.
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Affiliation(s)
- S Henriquez
- Laboratorio de Inmunología de la Reproducción, Universidad de Santiago de Chile
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Hubacher D, Reyes V, Lillo S, Zepeda A, Chen P, Croxatto H. Pain from copper intrauterine device insertion: randomized trial of prophylactic ibuprofen. Contraception 2006. [DOI: 10.1016/j.contraception.2006.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Hubacher D, Reyes V, Lillo S, Zepeda A, Pierre-Louis B, Croxatto H. Preventing early copper IUD removals among first-time users: placebo-controlled randomized trial to study the effect of prophylactic ibuprofen. Contraception 2005. [DOI: 10.1016/j.contraception.2005.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
As it approaches the maternal surface, the attaching embryo encounters the epithelial glycocalyx, which contains the mucin, MUC1. A high density of MUC1 at the cell surface can inhibit cell adhesion. This raises the possibility of the existence of a uterine barrier to implantation that might allow maternal rejection of poorer quality embryos. To investigate the mechanism of implantation, human embryos were incubated with endometrial epithelial monolayers. Hatched blastocysts were found to attach readily to the epithelial surface. MUC1 was lost from epithelial cells beneath and near to the attached embryo, while normal expression persisted in neighbouring cells.
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Affiliation(s)
- J D Aplin
- Schools of Medicine and Biological Sciences, University of Manchester, St Mary's Hospital, Manchester M13 0JH, U.K.
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Petta CA, Hays M, Brache V, Massai R, Hua Y, Alvarez-Sánchez F, Croxatto H, d'Arcangues C, Cook LA, Bahamondes L. Delayed first injection of the once-a-month injectable contraceptive containing 25 mg of medroxyprogesterone acetate and 5 mg of E(2)-cypionate: effects on ovarian function. Fertil Steril 2001; 75:744-8. [PMID: 11287029 DOI: 10.1016/s0015-0282(01)01672-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To assess whether women who were administered the first injection of DMPA+E(2)C on day 7 of their menstrual cycle (delayed injection) exhibit the same degree of ovarian suppression as women who receive it on day 5 of their menstrual cycle. DESIGN Multicenter, randomized controlled trial. SETTING Reproductive health clinics. PATIENT(S) Women aged between 18 and 38 years (inclusive) willing to use DMPA+E(2)C as their method of contraception. INTERVENTION(S) Participants received a DMPA+E(2)C injection on day 5 (control group, n = 41) or day 7 (delayed-injection group, n = 117) of their menstrual cycle. MAIN OUTCOME MEASURE(S) Ovarian activity and follicular development determined by serial serum progesterone levels and vaginal ultrasound. RESULT(S) Participants who received DMPA+E(2)C on day 5 of their menstrual cycle (control group) exhibited no more than limited follicular growth (no follicle >16 mm). Of those women who received DMPA+E(2)C on day 7 of their menstrual cycle (delayed-injection group), 21 (18%) showed some follicular growth, of whom 4 (3%) ovulated. CONCLUSION(S) The first injection of DMPA+E(2)C given on day 7 of a menstrual cycle does not provide the same inhibition of ovarian activity as that observed when it is administered on day 5 of the menstrual cycle.
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Affiliation(s)
- C A Petta
- Department of Obstetrics and Gynecology, Universidade Estadual de Campinas, São Paulo, Campinas, Brazil.
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Bruni V, Croxatto H, De La Cruz J, Dhont M, Durlot F, Fernandes MT, Andrade RP, Weisberg E, Rhoa M. A comparison of cycle control and effect on well-being of monophasic gestodene-, triphasic gestodene- and monophasic desogestrel-containing oral contraceptives. Gestodene Study Group. Gynecol Endocrinol 2000; 14:90-8. [PMID: 10836195 DOI: 10.3109/09513590009167666] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This was an open-label multicenter study to compare the cycle control and effect on well-being of two oral contraceptives containing gestodene and one containing desogestrel. A total of 2419 healthy women < or = 41 years of age were randomized to receive oral contraceptives containing monophasic gestodene (Minulet; n = 806, mean age 24.5 years), triphasic gestodene (Tri-Minulet; n = 808, mean age 24.6 years) or monophasic desogestrel (Mercilon; n = 805, mean age 24.6 years). Subjects were to participate in the study for up to 13 treatment cycles. A modified Moos Menstrual Distress Questionnaire was used to evaluate menstrual symptoms and to assess overall well-being. A total of 698 women were withdrawn from the study, 154 due to adverse events. Cycle control with gestodene was superior to that with desogestrel at almost all time points, particularly for breakthrough bleeding and/or spotting, which occurred significantly less frequently with gestodene than with desogestrel at cycles 1-7 and 9-11 (p < 0.05). Generally, the proportion of subjects with breakthrough bleeding and/or spotting was almost twice as great with desogestrel as with gestodene. The duration of bleeding was not consistently different between the gestodene and desogestrel groups; however, the intensity of bleeding was greater with gestodene at all time points (p < 0.05). The latent period before withdrawal bleeding was significantly longer for monophasic gestodene at cycles 1-5 and 8-10 (p < 0.05). Treatment significantly improved overall well-being at cycles 6 and 9 with triphasic gestodene and at cycle 13 with desogestrel; however, no statistically significant differences among treatment groups in overall well-being scores or individual factors of well-being could be identified. All three treatments were well tolerated. The most common drug-related adverse events were headache (14.2%), breast pain (6.2%), nausea (4.1%), metrorrhagia (3.9%) and abdominal pain (3.5%). The incidence of adverse events in all treatment groups was similar, with the exception of metrorrhagia, which occurred in more patients in the desogestrel group than in the gestodene treatment groups (p < 0.05).
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Affiliation(s)
- V Bruni
- Dipartimento di Ginecologia, Perinatologia e Reproduzione Umana, Università degli Studi di Firenze, Italy
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Brache V, Massai R, Mishell DR, Moo-Young AJ, Alvarez F, Salvatierra AM, Cochon L, Croxatto H, Robbins A, Faundes A. Ovarian function during use of Nestorone(R) subdermal implants. Contraception 2000; 61:199-204. [PMID: 10827334 DOI: 10.1016/s0010-7824(00)00092-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nestorone(R) progestin (NES) is a potent 19-nor-progesterone derivative which is biologically inactive when administered orally; however, it is an excellent option for implant contraception. The objective of this study was to evaluate ovarian function during use of either one 4-cm or two 3-cm NES implants for 24 months. A total of 60 volunteers were enrolled in each dose group. Vaginal ultrasound (VUS) and blood sampling for determinations of estradiol (E(2)), progesterone (P) and NES serum levels were carried out twice a week for 6 consecutive weeks, beginning in months 1, 6, 12, 18, and 24 of implant use. Serum levels of NES declined with time, with a more pronounced decrease during the first 18 months of implant use; thereafter, NES levels remained stable until the end of the study at 24 months. Luteal activity was very infrequent during the first year of use (<3%) but increased during the second year, occurring in 27% and 35% of the sampling periods in the 1-implant group, and 2% and 16% of the sampling periods in the 2-implant group, at months 18 and 24 of use, respectively. No luteal activity was observed with NES levels above 80 pmol/L. Serum P levels in periods of luteal activity were significantly lower than those of controls. Persistent anovulatory follicles were the most common VUS finding and this was associated with E(2) levels that remained within the normal range (101-1500 pmol/L) in the majority of the sampling periods studied. Considering that a single implant offers advantage for insertion and removal, a new single NES implant is being developed with a slightly higher release rate, to reduce effectively the incidence of ovulation and provide a greater margin of safety beyond 2 years.
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Affiliation(s)
- V Brache
- PROFAMILIA, Santo Domingo, Dominican Republic
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Croxatto H, Figueroa X, Boric MP, Roblero J, Silva R, Albertini R. [Glucose in conjunction with peptides derived from kininogens might act from digestive tract as blockers of atrial natriuretic peptide mediated diuresis-natriuresis]. Rev Med Chil 1998; 126:88-95. [PMID: 9629759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This paper describes long term research efforts which have lead: 1) to the identification of peptides present in pepsanurin, a peptidic fraction obtained by pepsin hydrolysis of plasma globulins that inhibits the renal excretory action of atrial natriuretic peptide (ANP) and 2) to the discovery of an unexpected role of glucose, as a requisite for these inhibitory effects. The active peptides identified in pepsanurin are derived from plasma kininogens, substrates of the kallikrein-kinin system. Pro-kinins of 15, 16 and 18 amino acids, and bradykinin itself, block ANP-induced diuresis and natriuresis when injected i.v., i.p. or into the duodenal lumen of anesthetized rats in picomol doses. Furthermore, a novel 20 amino acids fragment derived from kininogen dominium-1, named PU-D1, is the most potent and longer lasting blocker of ANP renal effects. The anti-ANP effects of those peptides are prevented by B2-kinin receptor antagonists. The inhibition of ANP by kinins and PU-D1 was evident only in rats infused with isotonic glucose; whereas the excretory effect of ANP was not affected in fasted rats not infused, or infused with saline. These findings provide evidence that glucose facilitates liquid retention through a kinin-mediated inhibition of ANP excretory action that may be related to the prandial cycle.
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Affiliation(s)
- H Croxatto
- Departamento de Ciencias Fisiológicas, Facultad de Ciencias Fisiológicas, Pontificia Universidad Católica, Santiago, Chile
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Abstract
Subdermal contraceptive implants involve the delivery of a steroid progestin from polymer capsules or rods placed under the skin. The hormone diffuses out slowly at a stable rate, providing contraceptive effectiveness for 1-5 years. The period of protection depends upon the specific progestin and the type of polymer. Advantages of progestin implants include long term contraceptive action without requiring the user's or provider's attention, low dose of highly effective contraception without the use of estrogen, and fertility is readily reversible after the removal of implants. The levonorgestrel implant Norplant R system is the only one that has been approved for distribution. The contraceptive efficacy of Norplant is the highest observed amongst the most effective methods with an annual pregnancy rate of 0.2 during the first and second year and 1.1 on the fifth year. Menstrual problems are the main reason for the discontinuation of Norplant and 9% of women stopped using it during the first year of treatment. Other implants are still under development trying to simplify the method by reducing the number of units and to introduce other progestins that may minimize side effects. Norplant-2 was designed to release the same dose of progestin from only two covered rods. Evaluation of 1400 women enrolled, indicates that over 2 years the cumulative pregnancy rate is below 0.5 per 100 women. There are three single implants under development: Nestorone, 3-Keto-desogestrel and Uniplant that are expected to be effective for 1-2 years. Phase II clinical trials with Nestorone have been completed and no pregnancies have been observed in 1570 woman-months of use. Bleeding irregularities occurred in 20-30% of the women but there were only four terminations because of bleeding problems. A multricentric study is ongoing with a newly designed 3-keto-desogestrel implant named Implanon, which releases approx. 60 micrograms/day of the hormone. The objectives of this study are to assess contraceptive efficacy, safety and acceptability of Implanon. Another multricentric study is ongoing with Uniplant, which releases nomegestrol acetate with a duration of action for only 1 year. The objectives of the trial are to study the endocrine profile of Uniplant users and to evaluate the efficacy and acceptability of the method.
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Affiliation(s)
- O Peralta
- Instituto Chileno de Medicina Reproductiva (ICMER), Santiago
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Croxatto H, Boric M, Roblero J, Albertini R, Silva R. [Digestive process and regulation of renal excretory function: pepsanurin and prokinin inhibit the natriuretic peptide diuretic action]. Rev Med Chil 1994; 122:737-45. [PMID: 7732222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In order to clarify the blunting effect of peptides released by pepsin from blood plasma on ANP diuretic action, two prokinins designated PU-18 and PU-16 were tested. Both of them were able to inhibit in nanomolar doses the diuretic-saluretic action of 0.5 ug i.v. bolus of ANP given to anesthetized rats either by intravenous route or introduced in the duodenal lumen. PU-16 in doses of 0.5 and 1 ug were able to reduce in 72 and 96.5% respectively the natriuresis induced by 0.5 ug intravenous bolus of ANP. The data support the hypothesis that prokinins liberated in the digestive tract, could be physiological factors involved in hydrosaline homeostasis, moderating the ANP mediated increase of water, Na and K excretion during digestion.
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Affiliation(s)
- H Croxatto
- Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, P Universidad Católica de Chile, Santiago de Chile
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Besio M, Barrena N, Croxatto H. [Verrucous carcinoma in the cervix uteri. Report of a case]. Rev Chil Obstet Ginecol 1993; 58:401-404. [PMID: 7991862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
One observed case of verrucous carcinoma involving the uterine cervix is presented. Both clinical and pathologic aspects, and pertinent literature are discussed.
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Affiliation(s)
- M Besio
- Servicio Obstetricia y Ginecología Hospital Parroquial de San Bernardo
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Affiliation(s)
- E Guarda
- Departamento de Enfermedades Cardiovasculares, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago
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Guarda E, Corbalán R, Croxatto H, Silva R, Vergara T, Valenzuela C, Albertini R. [Pepsanurin in congestive heart failure]. Rev Med Chil 1991; 119:137-41. [PMID: 1840459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have identified a plasmatic substance, "pepsanurin" (PU) obtained by pepsin hydrolysis which inhibits the renal effects of the atrial natriuretic factor (ANF). To investigate whether patients with congestive heart failure (CHF) have increased plasma levels of PU we prepared PU from 10 patients with CHF class IV (NYHA), 9 patients with CHF class II or III and 16 healthy controls. Anesthetized rats were used to test the effects of ANF, 0.5 ug/100 g body weight i.v., before and following the intraperitoneal injection of 0.5 ml of PU. The inhibition of the diuretic and natriuretic effects of ANF was 40.9 +/- 11.9% and 49.8 +/- 12% respectively for control subjects. Corresponding figures for class IV CHF patients were 62.3 +/- 3.1% and 73.8 +/- 3.5% (p less than 0.02) and for class II-III patients 39.2 +/- 7.0% and 53.1 +/- 8.2% (NS). Accordingly, an increased capacity to generate PU may underlie the decreased sensitivity to ANF in patients with advanced CHF.
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Affiliation(s)
- E Guarda
- Departamento de Enfermedades Cardiovasculares, Facultad de Medicina, Pontificia Universidad Católica de Chile
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Lähteenmäki PL, Diaz S, Miranda P, Croxatto H, Lähteenmäki P. Milk and plasma concentrations of the progestin ST-1435 in women treated parenterally with ST-1435. Contraception 1990; 42:555-62. [PMID: 2272183 DOI: 10.1016/0010-7824(90)90082-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A subcutaneous contraceptive capsule releasing progestin ST-1435 was used by 6 breast-feeding women. One to three paired milk and plasma samples were collected over a one-month period and the concentrations of ST-1435 were determined by radioimmunoassay. An improved and sensitive method for determination of ST-1435 in milk was developed. A column chromatographic purification of milk prior to radioimmunoassay decreased the blank and improved sensitivity. The average plasma concentration of ST-1435 was 62 +/- 20 pg/ml (mean +/- SD). The average milk concentration of ST-1435 was 38 pg/ml (ranging from 7 to 73 pg/ml), while the average milk to plasma ratio was 0.60 (ranging from 0.25 to 0.91). There was a significant correlation between ST-1435 concentrations in breast milk and plasma, indicating that the concentration in plasma is the major determinant for the amount of ST-1435 excreted into milk. Since studies with this drug have shown good contraceptive efficacy and low bioavailability after oral intake, ST-1435 is a good candidate for lactational contraception.
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Affiliation(s)
- P L Lähteenmäki
- Department of Medical Chemistry, University of Helsinki, Finland
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Heikinheimo O, Croxatto H, Salvatierra AM, Chang CC, Luukkainen T, Lähteenmäki P. Intravaginal administration of RU 486 in humans and rats: inadequate absorption in humans. Hum Reprod 1987; 2:645-8. [PMID: 3437043 DOI: 10.1093/oxfordjournals.humrep.a136608] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Vaginal absorption of the antiprogesterone steroid RU 486 was studied in humans and rats. In rats, RU 486 was sufficiently absorbed to terminate early pregnancy following vaginal, oral or intramuscular administration. The quantitation of RU 486 in serum showed that the ratios of the areas under the concentration curves per mg administered were 1:2.8:3.4 for the vaginal, intramuscular and oral routes, respectively. Female volunteers received RU 486 vaginally in polyethylene glycol (PEG) suppositories, in tampons and in oil solution. Following vaginal (PEG-suppository) and oral administration of 100 mg of RU 486, the ratio of the areas under the serum concentration curves was 1:56, respectively. From tampons and oil, RU 486 was absorbed in a similar manner to that of the PEG-suppositories, resulting in nanomolar serum concentrations. In humans no biological effects were noted following vaginal administration of RU 486. These data suggest that vaginal release of RU 486 is not a successful route of administration in humans.
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Affiliation(s)
- O Heikinheimo
- Department of Medical Chemistry, University of Helsinki, Finland
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Heikinheimo O, Lähteenmäki PL, Koivunen E, Shoupe D, Croxatto H, Luukkainen T, Lähteenmäki P. Metabolism and serum binding of RU 486 in women after various single doses. Hum Reprod 1987; 2:379-85. [PMID: 3654927 DOI: 10.1093/oxfordjournals.humrep.a136554] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The metabolism of RU 486 was studied in female volunteers following a single oral administration of 100, 400, 600 or 800 mg of RU 486. The serum concentrations of RU 486 were generally not affected by the dose within the range examined and they stayed at micromolar concentrations during the 48 h studied. RU 486 was metabolized extensively in a dose-dependent manner by two-step demethylation, and by hydroxylation. Serum levels of the monodemethylated metabolite always exceeded those of RU 486. The concentrations of the didemethylated and hydroxylated metabolites equalled or exceeded those of RU 486 when the ingested dose was 400 mg or more. Monodemethylation and hydroxylation were rapid high-capacity reactions, whereas didemethylation was a lower-capacity reaction. In each group of different dosage, positive correlations were found between the individual mean alpha 1-acid glycoprotein (AAG) concentrations and the peak concentration of RU 486 measured at 1-2 h, versus the plateau concentration of RU 486 measured at 6 h. The in-vitro studies showed that the specific serum transport protein of RU 486, AAG, was saturated by RU 486 concentrations exceeding 2.5 microM. In serum at 40 nM and 2.5 microM RU 486 concentrations, 2.7% and 2.4%, respectively, of [3H]RU 486 was not protein bound. Purified AAG in phosphate buffer was able to bind [3H]RU 486 in a similar manner to that of serum. Thus our results suggest that AAG regulates in part the serum concentrations of RU 486, and RU 486 exceeding the specific serum transport capacity is effectively metabolized.
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Affiliation(s)
- O Heikinheimo
- Department of Medical Chemistry, University of Helsinki, Finland
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Heikinheimo O, Kontula K, Croxatto H, Spitz I, Luukkainen T, Lähteenmäki P. Plasma concentrations and receptor binding of RU 486 and its metabolites in humans. J Steroid Biochem 1987; 26:279-84. [PMID: 3560943 DOI: 10.1016/0022-4731(87)90083-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Using Chromosorb chromatography and HPLC, we measured the plasma concentrations of RU 486, and its monodemethylated (RU 42633), didemethylated (RU 42848) and alcoholic nondemethylated (RU 42698) metabolites up to 72 h following oral ingestion of 100 mg of RU 486 by five female volunteers. The peak plasma level of RU 486 (4.5 mumol/l) occurred within 1 h after ingestion of the compound; at this point significant amounts of the metabolites were also present in the plasma. After the initial redistribution within 6 h the plasma concentrations of RU 486 and three of its metabolites measured remained stable for 24 h. Concentrations of the monodomethylated metabolite exceeded those of the parent steroid during the time period measured, whereas the concentrations of the didemethylated and alcoholic metabolites were lower than those of RU 486, but still notable. At 72 h the concentrations of all the four steroids were still in the micromolar range. The relative binding affinities of these metabolites to human endometrial and myometrial progesterone receptors as well as to human placental glucocorticoid receptors were determined in vitro. The affinity of RU 486 for the human uterine progesterone receptor (Kd = 1.3 X 10(-9) M for RU 486) was higher than that of progesterone but lower than that of ORG-2058, a potent synthetic progestin. The relative binding affinities of the monodemethylated, alcoholic and didemethylated metabolites to the progesterone receptor were 21, 15 and 9%, respectively, compared with the parent compound RU 486; each was lower than that of progesterone (43%). RU 486 had an approx. 4-fold higher relative binding affinity to the glucocorticoid receptor than dexamethasone. Interestingly, the relative binding affinities of the metabolites studied to the human glucocorticoid receptor exceeded those of dexamethasone or cortisol. Compared with the parent compound RU 486, they were 61, 48 and 45% for the monodemethylated, alcoholic and didemethylated metabolites, respectively; each was higher than that of dexamethasone (23%). The affinity of dexamethasone to the human glucocorticoid receptor was 1.6 X 10(-9) M. These data indicate that the pool of certain metabolites of RU 486 may contribute to a significant extent to the antiprogestagenic (23-33%) and even greater extent to the antiglucocorticoid (47-61%) effects of RU 486.
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Lähteenmäki P, Heikinheimo O, Croxatto H, Spitz I, Shoupe D, Birgerson L, Luukkainen T. Pharmacokinetics and metabolism of RU 486. J Steroid Biochem 1987; 27:859-63. [PMID: 3695508 DOI: 10.1016/0022-4731(87)90160-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effects of dose on the initial pharmacokinetics and metabolism of an antiprogesterone steroid RU 486 (mifepristone) were studied in healthy female volunteers after administration of RU 486 as a single dose of 50-800 mg. The concentrations of RU 486 and its monodemethylated, dimethylated and hydroxylated non-demethylated metabolites were measured specifically after Chromosorb-column chromatography by HPLC. Their relative binding affinities to the human uterine progesterone receptor were also determined. Micromolar concentrations of the parent compound in blood were reached within the first hour after oral administration. The pharmacokinetics of RU 486 followed two distinct patterns in a dose-dependent fashion. With a low dose of 50 mg the pharmacokinetics followed an open two-compartment model with a half-life of over 27 h. With the doses of 100-800 mg the initial redistribution phase of 6-10 h was followed by zero-order kinetics up to 24 h or more. Importantly, after ingestion of doses higher than 100 mg of RU 486 there were no significant differences in plasma concentrations of RU 486 within the first 48 h, with the exception of plasma RU 486 concentrations at 2 h. After single oral administration of 200 mg unchanged RU 486 was found 10 days later in two subjects. The elimination phase half-life with this dose, calculated between day 5 and 6, was 24 h. Micromolar concentrations of monodemethylated, didemethylated and non-demethylated hydroxylated metabolites were measured within 1 h after oral administration of RU 486. In contrast to plasma RU 486 concentrations, circulating plasma concentrations of metabolites increased in a dose-dependent fashion. With higher doses the metabolite concentrations were close to, or even in excess to the parent compound. The relative binding affinities of RU 486, monodemethylated, didemethylated and hydroxylated metabolites (progesterone = 100%) to the human progesterone receptor were 232, 50, 21, and 36, respectively. The existence of a high affinity-limited capacity serum binding protein would explain the long half-life and the observed diverging dose-dependent pharmacokinetics. The extravasation of RU 486 after the saturation of serum binding sites would explain the blunted serum peak concentrations of RU 486 with higher doses. The return of the drug back to circulation thereafter explains the zero-order kinetics. High concentrations of circulating metabolites capable of binding to the progesterone receptor suggest a significant contribution of these steroids in the overall antiprogestational action.
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Affiliation(s)
- P Lähteenmäki
- Department of Medical Chemistry, University of Helsinki, Finland
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Heikinheimo O, Tevilin M, Shoupe D, Croxatto H, Lähteenmäki P. Quantitation of RU 486 in human plasma by HPLC and RIA after column chromatography. Contraception 1986; 34:613-24. [PMID: 3829676 DOI: 10.1016/s0010-7824(86)80017-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Chromosorb column chromatography was used for separation of RU 486 from its immunologically cross-reacting metabolites prior to quantitative analysis by radioimmunoassay (RIA) or high-performance-liquid chromatography (HPLC). The results of the two assay methods were in good agreement with each other (r = 0.99, n = 29). The retention time of RU 486 in our HPLC system was 2.5 min. Plasma concentrations of RU 486 were measured by HPLC up to 48 h following single oral administration of 100, 400, 600 and 800 mg of RU 486 to female volunteers. The plasma peak concentrations (2.0-2.5 micrograms/ml) were reached within the first hour. After redistribution, the plasma concentrations of RU 486 were not significantly affected by the doses studied but remained in the same range throughout the 48 hours. The plasma half-life between 24 and 48 hours was 27 hours or more. We conclude that HPLC is valuable in studies on the metabolism and pharmacokinetics of RU 486, but a less laborious RIA method after Chromosorb column chromatography is suitable and gives reliable results in large-scale clinical studies.
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Díaz A, Caracci M, Valdebenito J, Mege RM, Calvo A, Ramírez E, Croxatto H, San Martín S, Buchheister M. [Severe acute pancreatitis: early surgical treatment]. Rev Med Chil 1986; 114:752-9. [PMID: 3575959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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23
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Abstract
Venous aneurysms are extremely rare. They may be congenital or acquired in origin and occasionally related to arteriovenous communications. A 58-year-old man complained of dull left lower quadrant pain and constipation. On physical examination a soft deep mass was palpated. Ultrasonogram and CT scan revealed a cystic formation in the pelvic cavity. Angiograms disclosed an arteriovenous malformation (AVM) at the pelvic floor draining into a large cavity. The patient was successfully managed by intraoperative selective embolization of the AVM and partial resection of a 10.6 x 8 x 6.7 cm venous aneurysm. The histopathologic studies of the wall confirmed a venous structure. Venous dilatation has been reported in high flow vein grafts, blood access V fistulas and rarely, proximal to traumatic AV fistulas of the lower extremities. The etiology of the present case is probably congenital, being to the best of our knowledge, the first case affecting the hypogastric territory, reported in the English literature.
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Affiliation(s)
- F Valdes
- Department of Vascular Surgery, Catholic University Hospital and School of Medicine, Santiago, Chile
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24
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Croxatto H. [Homage to Dr. Teodoro Muhm (1869-1939)]. Rev Med Chil 1984; 112:81-8. [PMID: 6377431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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López JM, Arteaga E, Rodriguez JA, Croxatto H. Increased Excretion of Kallikrein during Dexamethasone Administrationl in Normal Man on Low and Normal Salt Intake. Clin Sci (Lond) 1983; 65:487-90. [PMID: 6555065 DOI: 10.1042/cs0650487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
1. The effect of dexamethasone administration for 3 days on urinary kallikrein excretion was studied in 12 normal men with normal sodium intake (n=6) or low sodium intake (n=6). Urinary excretion of sodium, potassium, 17-hydroxycorticosteroids, aldosterone and water was also measured in all subjects.
2. Dexamethasone administration was associated with a significant increase in urinary kallikrein excretion (F3, 30 = 6.9; P < 0.001) regardless of sodium intake. No significant correlation could be established between the increase in urinary kallikrein excretion and changes in urinary sodium, potassium, 17-hydroxycorticosteroids, aldosterone or water.
3. These results suggest that dexamethasone can exert a direct action on the renal kallikrein-kinin system.
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Faundes A, Croxatto H, Alvarez F, Diaz S, Brache V, Segal SJ. [Hormonal contraception with subdermal implants (author's transl)]. Contracept Fertil Sex (Paris) 1983; 11:815-20. [PMID: 12338739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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27
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Arteaga E, López JM, Croxatto H. [24-hour urinary kallikrein excretion profile in the normal human]. Rev Med Chil 1982; 110:333-6. [PMID: 6925289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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28
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Zuñiga A, Quintana C, Croxatto H, Díaz F. [Surgical treatment of Crohn's disease (author's transl)]. Rev Med Chil 1980; 108:507-11. [PMID: 7466003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Cubillos L, Medina F, Croxatto H, García C. [Left colon deformities secondary to acute pancreatitis (author's transl)]. Rev Med Chil 1980; 108:512-8. [PMID: 7466004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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30
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Tocornal J, Monge JI, Croxatto H, Miranda MC. [Non-carcinomatous tumoral and pseudotumoral lesions of the ampulla of Vater (author's transl)]. Rev Med Chil 1980; 108:430-4. [PMID: 7433798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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31
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Das C, Talwar GP, Ramakrishnan S, Salahuddin M, Kumar S, Hingorani V, Coutinho E, Croxatto H, Hemmingson E, Johansson E, Luukkainen T, Shahani S, Sundaram K, Nash H, Segal SJ. Discriminatory effect of anti-Pr-beta-hCG-TT antibodies on the neutralization of the biological activity of placental and pituitary gonadotropins. Contraception 1978; 18:35-50. [PMID: 98287 DOI: 10.1016/0010-7824(78)90100-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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32
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Roblero J, Croxatto H, García R, Corthorn J, De Vito E. Kallikreinlike activity in perfusates and urine of isolated rat kidneys. Am J Physiol 1976; 231:1383-9. [PMID: 793423 DOI: 10.1152/ajplegacy.1976.231.5.1383] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In the perfusate and the urine produced during perfusion of isolated rat kidneys a kallikreinlike enzyme similar to that found in the kidney was detectable by bioassay 15-25 min after the beginning of the perfusion. The source of the kallikrein activity was the kidney itself, since before the perfusion was started the blood remaining in the kidneys was washed out and the perfusion medium was free of kallikrein and its precursors and substrates. The kallikreinlike activity of the perfusate was characterized by a) an oxytocic effect on isolated rat uterus, b) a kininogenase activity on kininogen II, c) an esterase activity on N-benozyl-L-arginine ethyl ester, and d) a hypotensive effect on anethetized rats. These properties were inhibited by diisopropyl activity in the perfused kidney was lower than that in the nonperfused organ, but the total amount of kallikrein activity released to the excreted urine and the perfusate was significantly greater than the corresponding activity that disappeared in the kidney. This result is in keeping with the concept that the renal tissue is able to synthesize kallikrein.
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Zañartu J, Rosner JM, Guiloff E, Ibarra A, Cheviakoff S, Croxatto HD, Croxatto H, Dabancens A, Coy DH, Schally AV. [Synthetic hypothalamic gonadotropin-releasing hormone (LH-RH) and ovulation: a possibility of "programmed" ovulation to regulate fertility in women (author's transl)]. Rev Med Chil 1975; 103:775-9. [PMID: 1108143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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34
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Greco AV, Porcelli G, Ghirlanda G, Altomonte L, Croxatto H. [Urinary kallikrein excretion in hepatic cirrhosis]. Minerva Med 1975; 66:1504-8. [PMID: 1143688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Measurements of urinary kallikrein using an esterolytic assay revealed higher levels in patients with liver cirrhosis than in a control population. The range of excretion in 33 patients with cirrhosis was from 18.68 to 85.20 E.U. per 24 hours with a mean excretion of 39.42 plus or minus 2.84 E.U. Kallikrein excretion in the control group ranged from 13.20 to 39.50 E.U. per 24 hours with a mean of 24.44 plus or minus 1.66 E.U.
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35
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Cubillos L, Mac-Cawley A, Croxatto H. [Benign tumors and pseudotumoral lesions of the stomach]. Rev Clin Esp 1974; 134:157-62. [PMID: 4438722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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36
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Croxatto H. [Kallikrein versus renin? Changes in kallikrein excretion in experimental hypertension and other conditions]. Rev Med Chil 1972; 100:708-17. [PMID: 5083357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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39
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Porcelli G, Croxatto H. Purification of kininogenase from rat urine. Ital J Biochem 1971; 20:66-88. [PMID: 5156704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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40
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Croxatto H, Díaz S, Vera R, Etchart M, Atria P. Fertility control in women with a progestogen released in microquantities from subcutaneous capsules. Am J Obstet Gynecol 1969; 105:1135-8. [PMID: 5352594 DOI: 10.1016/0002-9378(69)90140-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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41
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Croxatto H, Cruzatt H. Ineffectiveness of carboxypeptidase B in inhibiting the pressor effect of incubated human plasma. Experientia 1969; 25:59-60. [PMID: 5766583 DOI: 10.1007/bf01903895] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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42
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Croxatto H, Labarca E, Swaneck G, Garfias P. Effect of growth hormone on Na, K, and water renal excretion induced by renin. Am J Physiol 1966; 211:588-92. [PMID: 5927886 DOI: 10.1152/ajplegacy.1966.211.3.588] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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43
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De Los Reyes MP, Croxatto H, Cruz-Coke R, Medina E, Orellana JM, Roa A. [Medical problem of using contraceptive agents in birth control]. Rev Med Chil 1966; 94:461-77. [PMID: 5996897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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44
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Barnafi L, Croxatto H. Vasopressor and oxytocic activites in the posterior lobe of the pituitary gland of male and female rats ollowing adrenalectomy and gonadectomy. Acta Endocrinol (Copenh) 1966; 52:3-6. [PMID: 5952692 DOI: 10.1530/acta.0.0520003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
ABSTRACT
The vasopressor and oxytocic activities in the posterior lobes of the pituitary gland were found to be markedly higher in female than in male rats.
Whereas adrenalectomy decreased these activities in the males, it produced no changes in the female.
Gonadectomy lowered the vasopressor activity in males, but had no effect on oxytocic activity. Ovariectomy decreased oxytocic activity, but produced no significant changes in vasopressor activity.
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De la Lastra M, Croxatto H. Diurnal variations in ovarian ascorbic acid content of pseudopregnant immature rats used in Parlow's test. Nature 1965; 208:789-90. [PMID: 5868893 DOI: 10.1038/208789a0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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46
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