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At least 145 records · Page 8Linked to original sources
PubMed1985

Increased euglobulin fibrinolytic potential in women on oral contraceptives low in oestrogen--levels of extrinsic and intrinsic plasminogen activators, prekallikrein, factor XII, and C1-inactivator.

Components of the fibrinolytic system were studied in samples of plasma from 15 normal, young women and from 11 women taking oral contraceptives containing 30 micrograms ethinyl oestradiol and 150 micrograms levo-norgestrel. Fibrinolytic activity of euglobulins precipitated at pH 5.9 was higher than normal in the hormone group, with significant fluctuations related to the cycle. Normal women showed only minor fluctuations. The concentration of C1-inactivator was lower in euglobulins of the hormone group. However, the difference in fibrinolytic activity was retained, when C1-inactivator was inactivated with sodium flufenamate. Fluctuations of the extrinsic (tissue-type) plasminogen activator (t-PA) activity parallelled those of the euglobulin activity. The intrinsic plasminogen activator activity (dextran sulphate precipitated euglobulin) was significantly increased in the hormone group and the cyclic pattern differed from that of the normal group. The increased activity was factor XII-dependent. Plasma prekallikrein did not differ. The factor XII level was increased in the hormone group but this could not explain the increased intrinsic fibrinolytic activity, suggesting an increase in the quantity of an additional factor XII-dependent proactivator.

Adult↗
PubMed1985

Relationships between tissue plasminogen activator, steroid hormones and deep vein thrombosis.

The plasma concentrations of tissue plasminogen activator (t-PA) antigen, cortisol, testosterone, dehydroepiandrosterone sulphate, FSH and LH were studied in 33 men undergoing major abdominal surgery. Significant positive correlation was found between the concentrations of t-PA antigen and cortisol, suggesting that the adrenal cortex has a role in the regulation of extrinsic fibrinolysis. These two variables, however, did not distinguish between patients with postoperative deep vein thrombosis (diagnosed by 125I-fibrinogen uptake test) and those without this complication. Such distinction was possible, however, with another steroid hormone of the adrenal cortex, dehydroepiandrosterone sulphate. At present, no explanation in terms of haemostatic mechanisms can be offered for this finding.

Adrenal Cortex Hormones↗
PubMed1977

[The effect of several sexual steroids, 2-bromo-ergokryptin and lisurid-hydrogenmaleate an the postpartum concentration of serum prolactin and lactation (author's transl)].

The effect of Ablacton, Estrovis 4000, 2 Brom-alpha-ergokryptin (Cb 154) and of Lisurid-hydrogenmaleate (LHM) on lactation and the serum concentration of prolactin postpartum was studied. 10 normal nursing postpartum patients served as control. LHM was tested in a double blind study compared to placebo. The serum prolactin (PRL) was determined daily for the first 10 postpartum days by radioimmunoassay. Inhibition of lactation was consistent with Cb 154 (89% of the cases). Within two to three days after the onset of treatment with Cb 154 the changes of pregnancy in the breasts had completely subsided. The sexual steroids resulted in inhibition of lactation in 60% of the postpartum patients but mastodynia continued. LHM showed no difference from group taking placebo. The serum prolactin levels postpartum remained as high as a nursing mother's or rose with the administration of steroids. The administration of Cb 154 resulted in a drop of the serum prolactin to non-pregnant levels with in 2 days. The serum prolactin levels under treatment with LHM were not different from the group slowly. In nursing mothers, the stimulus of suckling maintain the pituitary secretion of prolactin as showed by higher serum prolactin levels and a slower decreased to normals than in the non-nursing mothers.

Bromocriptine↗
PubMed1994

Contraception in women with intercurrent disease.

Prescribing a contraceptive method for women with intercurrent disease poses a difficult clinical management problem for physicians. The contraceptive chosen may adversely affect the underlying disease of the patient. Conversely, failure of contraception could result in pregnancy, which could also adversely affect the patient's underlying disease. These factors must be taken into consideration in selecting appropriate and effective contraceptive agents to avoid complications and undesired pharmacologic interactions.

Blood Coagulation Disorders↗
PubMed1994

The effect of the phase of the menstrual cycle and the birth control pill on athletic performance.

Investigators are not in agreement on the effects of either the phase of the menstrual cycle, or the administration of OCAs on athletic performance. It appears, however, that apart from subtle changes in some variables, for most women there is no significant effect. Medals have been won and world records set in any phase of the menstrual cycle, and also by women taking OCAs. In terms of documentation of cycle phase, newer hormonal measurement techniques such as the levels of urinary luteinizing hormone (LH) to detect ovulation or salivary progesterone, should make it easier in the future to obviate the methodologic difficulties encountered in earlier studies. Further studies should also focus on the midcycle estradiol surge as well, in order to determine the relative contributions of estrogen and progesterone to any observed performance changes. Given the possibility that some cardiovascular, respiratory, and metabolic variables may change slightly during the course of a regular ovulatory menstrual cycle, it behooves researchers who are using women as subjects in other types of studies to standardize the menstrual cycle phase in which they are tested, in order to eliminate any possible confounding effects due to hormonal variation. Regarding the effects of oral contraceptives on performance, any conclusions from the studies to date are complicated by the proliferation of preparations currently on the market. Further studies are needed on monophasic, biphasic and triphasic formulations, including OCAs with the newer progestins (desogestrel, gestodene and norgestimate), as well as the progesterone-only agents (both oral and injectable). Prospective double blind randomized studies must be done, using a proper control group. The difficulty with this technique, however, is that women in the control group will inevitably be in various phases of the cycle, so accurate hormonal documentation is also essential in order to correctly interpret the findings. Just as the past few decades have seen a significant advancement in the participation of women in sports, future years should bring an enhanced scientific knowledge base about the interactions of the special hormonal considerations of the exercising woman throughout her reproductive life cycle.

Adult↗
PubMed1976

Oral contraceptive, pulmonary artery thrombosis and anti-ethinyl-oestradiol monoclonal IgG.

Pulmonary artery thrombosis and an anti-ethinyl-oestradiol monoclonal IgGlambda were found to be associated in a 36-year-old woman (Mrs MAI.) who took an oral contraceptive containing 50 mug ethinyl-oestradiol and 500 mug nor-ethisterone daily. After appropriate purification including methods by which the IgG was separated of bound circulating hormones, its binding activity was demonstrated by several methods: passive haemagglutination of oestradiol-benzoate sensitized red blood cells; gel filtration on Sephadex G-25; ultracentrifugation and equilibrium dialysis. IgGlambda MAI bound ethinyl oestradiol (Ka=2-7 X 10(1) M-1) and also 17-beta-oestradiol, with a lower affinity (Ka=0-4 X 10(7) M-1). The valency for these two hormones was near 2. Ethinyl-oestradiol bound to the IgG was displaced by ethinyl-oestradiol itself and in decreasing order of potency by 17-beta-oestradiol, progesterone, oestriol, and testosterone. Oestrone and hydrocortisone had no effect. Although the localization of the binding sites of this IgGlambda was not studied, it is likely that they were the antibody sites of the molecule and, according to immunochemical criteria, it may be classified as a monoclonal anti-ethinyl-oestradiol antibody. It is felt that its association with the pulmonary thrombosis and the oral contraceptive may be significant. This supports the hypothesis of an immunological mechanism for the unexplained thrombotic risk of oral contraceptives.

Adult↗
PubMed1997

[Contraceptive agents and risk of thrombosis].

In the late sixties and seventies, publications of the Royal College of General Practitioners in England reported that in women using oral contraceptiva the incidence of venous thromboembolism is increased by two to four fold. Moreover, it was demonstrated, that these alterations in coagulation were induced by ethinylestradiol in a dose dependent manner. Following these findings, its dosage was lowered from more than 100 micrograms to 20-30 micrograms per day. More recently, the role of gestagens in inducing thrombosis has also been debated. Different authors observed an increased risk for venous thromboembolism in women using third generation pills containing gestoden or desogestrel compared with users of second generation levonorgestrel contraceptiva. These reports have generated a lot of concern and fear in the patients as well as doctors and have led to a drastic fall in the use of oral contraceptives. Due to the unavailability of safe contraceptive alternatives, the number of women experiencing unwanted pregnancy and its complications increased significantly. Indeed, direct proof for the role of gestagens in inducing thromboembolism is still lacking as the protocol designs of these studies do not allow us to infer whether the effects are due to the gestagens or to confounding variables. Hence, the discussions were beneficial for clinicians to remember the importance of checking the patient for individual and family risks for thrombosis before handling out a pill prescription.

Contraceptives, Oral, Hormonal↗
PubMedDate not supplied

[Compensatory reactions of the oxygen-transport systems of the body with hemic hypoxia (studies on a mathematical model].

The mathematical model suggested by the authors and results of experiments have been used to study the significance of basic oxygen-transport systems in regulation of oxygen conditions of the organism with acute and chronic hemic hypoxia of different seriousness, to determine a relative contribution of each of them to compensation of this hypoxic state, to estimate specific weight of proper "hypoxic" (induced by the effect on oxygen-transport blood function) and "toxic" (caused by the total toxic effect) action of sodium nitrite in the development of hemic hypoxia.

Animals↗
PubMed1987

Influence of vitamin E administration on platelet functions in hormonal contraceptive users.

Platelet functions (aggregation, clotting activity), platelet lipid biosynthesis, sterol composition and phospholipid fatty acids were studied in relation to plasma lipids and fatty acids as well as dietary habits at day 5 and 21 of the menstrual cycle in 30 women having used hormonal contraceptive for several years. The women were studied again on day 21 of the second cycle after they had taken for two months 200 mg vitamin E per day in addition to the contraceptive. At day 21 (after 3 weeks of hormonal contraceptive) as compared to day 5, there was a significant increase in the clotting activity of platelets and the response to ADP-induced aggregation concomitant with a decrease in plasma vitamin E. After vitamin E administration, platelet activity at day 21 was markedly decreased, being similar to the activity at day 5, with a significant increase in the level of vitamin E in plasma and platelets. The high response of platelets to aggregation in women using contraceptives does not seem to be associated with the intake of saturated fat but rather with that of 18:2. The aggregation to thrombin was mostly related to lanosterol biosynthesis and the aggregation to ADP to platelet cholesterol, but not to plasma lipids or apoproteins. The present pilot study suggests that the platelet hyperactivity of long-term hormonal contraceptive users might be dependent upon a low level of platelet alpha-tocopherol which can be rapidly overcome by giving a supplement of vitamin E.

Adult↗
PubMed1994

Pharmacokinetics of levonorgestrel and ethinylestradiol in 14 women during three months of treatment with a tri-step combination oral contraceptive: serum protein binding of levonorgestrel and influence of treatment on free and total testosterone levels in the serum.

The pharmacokinetics of levonorgestrel (LNG) and ethinylestradiol (EE2) were determined in 14 healthy women (age 18 to 27 years) during a treatment period of three months with a tri-step combination oral contraceptive (Triquilar). Prior to this treatment period, the same women received a single administration of a coated tablet containing 0.125 mg LNG together with 0.03 mg EE2. There was a washout phase of one week between both treatments. Following single dose administration, a mean terminal half-life of 22 h was observed for LNG. The total clearance was 1.0 ml x min-1 x kg-1 and the volume of distribution was 128 l. During a treatment cycle, LNG levels in the serum accumulated by a factor of about four as compared to single dose administration. Steady-state drug levels were reached during the second half of each cycle. As compared to single dose administration, the following changes were observed for LNG at the end of treatment cycles one and three: reduced total (0.5 ml x min-1 x kg-1) and free clearance (50 ml x min-1 x kg-1) and a reduced volume of distribution (52 l). A concomitant increase in the SHBG concentrations by a factor of two as compared to pretreatment values was observed during treatment and appeared to be mainly responsible for the changes in the pharmacokinetics of LNG. Marked changes were also seen for the serum protein binding of LNG. After single dose administration, the free fraction of LNG was 1.4% and the fractions bound to SHBG and albumin were 55.0% and 43.6%, respectively. At the end of cycle one, the free fraction was only 1.0% and the fractions bound to SHBG and albumin were 69.4% and 30.0%, respectively. There was no difference in corresponding pharmacokinetic parameters and in the serum protein binding of LNG at the end of cycles one and three. On the last day of treatment cycles one and three, the AUC(0-4h) values of EE2 were 331.2 and 369.6 pg x ml-1 x h, respectively, which corresponds to an about 11-24% increase as compared to single dose administration, where an AUC(0-4h) value of 298.3 pg x ml-1 x h was found. Total and free testosterone concentrations decreased during treatment cycles one and three by about 41% and 55%, respectively, compared with the corresponding values measured prior to treatment.

Administration, Oral↗
PubMed1984

The effects of Depo-Provera on serum protein levels in Nigerian women.

The concentration of 13 serum proteins were determined in 50 women who had received the 3-monthly intramuscular injection of Depo-Provera for contraception over a mean period of 18 months and 40 women of comparable ages who served as controls. Sera from fasting subjects were used to determine the levels of each specific protein by quantitative immunodiffusion technique. Treatment with Depo-Provera produced increased serum levels of albumin, alpha 1-acid glycoprotein, alpha 2-macroglobulin, haptoglobin IgG; reduced levels of alpha 1-antitrypsin, transferrin, C3c, C4 but no change in serum IgA, IgM, C-reactive protein and ceruloplasmin. The significant alterations were observed in serum proteins that are notably synthesized by the liver, an observation consistent with the influences which gonadal hormones exert on the metabolic activities of this organ.

Blood Proteins↗