The content of sex hormones in the enteric medium of female ruminants

It has been established that in the chyme of females of the seep Ovis ammon and the reindeer Rangifer tarandus with an actively functioning corpus luteum of the estrous cycle or in pregnancy, the total amounts and concentrations of progesterone and estradiol are higher, while the progesterone/estradiol ratio, lower, than in the blood serum. The conclusion has been made that the transport of these hormones across the rumen wall occurs from the blood into the chyme, while across the cecal wall, from the chyme into the blood.     

Progesterone transport across the wall of the rumen of sheep

Data on content of fiber, lignin and progesterone in reticulo-ruminal chyme and progesterone in blood serum and saliva of sheep throughout the reproductive cycle and at intramuscular injection of progesterone, are presented. A direct correlation between concentration of progesterone in blood and chyme was revealed. 1.5% of progesterone entered the reticulo-rumen with saliva. Transport of hormone through the wall of forestomach is the main way of progesterone entering the reticulo-rumen. The transport is carried out against the gradient of hormone concentration. Possible participation of progesterone adsorption on lignin in explanation of this transport, is discussed.     

Gonadal and adrenal endocrine functions in female minks of 2 genotypes in postnatal ontogeny

Radioimmune assay has been made of the content of estradiol and progesterone in the blood (from July to March including the 7th day after mating), as well as on the level of estradiol and progesterone production in young females of the standard and mutant sapphire minks in November. It was shown that within certain periods, estradiol and progesterone content of the blood was significantly higher in the standard animals. Gonadal production of estradiol, as well as progesterone production both by the gonads and adrenals in November, were similar in females of both genotypes. It is suggested that sapphire minks have another pattern of correlation between estradiol content of the blood and gonadal production of estradiol as compared to that in standard animals.     

Effects of estradiol and progesterone on the variability of the micronucleus assay

To investigate chromosomal radiosensitivity of lymphocytes the micronucleus (MN) assay has been used for many years. The results of these studies suggest the use of the MN assay as a biomarker for cancer predisposition. However, the MN assay has still some limitations associated with the reproducibility and sensitivity. Especially a high intra-individual variability has been observed. An explanation for this high intra-individual variability is not yet available. In literature it is suggested that the high variability among females is attributable to hormonal status. In this study we investigated if the high intra-individual variability in micronucleus formation in lymphocytes of females after in vitro exposure to ionising radiation is caused by variations in hormone levels of estradiol (E2) and progesterone (PROG). For this, the MN assay was performed on blood samples of 18 healthy women during 7 consecutive weeks while the estradiol and progesterone levels were determined at the same time. The MN assay was also examined in cultures of isolated blood lymphocytes with estradiol or progesterone levels added in vitro. The results demonstrated that estradiol and progesterone levels have no influence on the variations in radiation-induced MN yields observed in blood samples of healthy women. These conclusions were confirmed by the "in vitro" experiments as no correlation between the MN yields and the concentrations of hormones (estradiol or progesterone) added in vitro to isolated lymphocytes cultures was observed.     

Effects of ovariectomy and steroid replacement on the genital tract of the viviparous lizard, Xantusia vigilis

Two glandular components are described in the genital tract of Xantusia: tubal glands in the Fallopian tube and goblet cells in the uterine villi. Sperm or seminal receptacles occur between adjacent villi in the uterus. Forty ovariectomized lizards carrying a silk loop in the wall of the left uterus were treated for two weeks with either progesterone, estradiol-17 β, progesterone plus estradiol or vehicle. Uteri with loops serving as a local irritant, did not differ significantly from the contra-lateral uteri in any group, hence a response similar to the deciduomal reaction of mammals is not found in this lizard. The weight of the genital tract is similar in sham-operated and in ovariectomized lizards injected with either progesterone or the vehicle. Maximal increase in weight of the tract is noted with estradiol treatment, while simultaneous administration of both steroids is followed by a moderate increase of oviducal weight. Tubal glands and sperm receptacles in ovariectomized lizards injected with either the vehicle or progesterone are smaller than those of the sham-operated or ovariectomized lizards treated with estradiol or with estradiol plus progesterone. Goblet cells are small and lack secretory granules in ovariectomized lizards injected with either the vehicle, or with estrogen or progesterone alone. Both steroids, given together, restore the size and apparent secretory activity of the goblet cells. It is concluded that in this viviparous species, both estrogen(s) and progestin(s) are essential for the maturation of the genital tract in the preovulatory stage.     

17beta-estradiol acts separately on the LDL particle and artery wall to reduce LDL accumulation

Estrogen replacement therapy has been shown to attenuate atherogenesis, although the mechanisms for this effect are incompletely defined. Previously, we showed that 17-beta estradiol (estradiol) attenuated oxidant stress-induced increases in vascular low density lipoprotein (LDL) accumulation. It was unclear whether estradiol's effect was imparted on the lipoprotein particle or the artery wall. To examine this, we chronically treated rats with the following sex hormones: low estradiol, high estradiol, progesterone, low estradiol + progesterone, placebo, or control. Carotid arteries (n = 8/group) were isolated and perfused with fluorescently labeled LDL. Rates of LDL accumulation were measured before and after treatment with 10 ng/ml tumor necrosis factor-alpha (TNF) using quantitative fluorescence microscopy. We observed a 50% decrease in basal LDL accumulation rates (P < 0.01) and a 25% decrease in endothelial layer permeability (P < 0.01) in arteries from estradiol-treated animals. There was no effect of hormone replacement on rate of TNF-induced LDL accumulation (P = 0.451), while incubation of LDL with 65 pg/ml estradiol attenuated the TNF effect (P < 0.01). These experiments suggest two independent mechanisms of anti-atherogenic protection by estradiol: 1) decreased endothelial layer permeability; and 2) incorporation of estradiol into the LDL particle and prevention of LDL binding to the artery wall.     

Peripheral blood concentrations of progesterone and oestradiol during human pregnancy and delivery

To evaluate the significance of progesterone and estradiol in human uterine activity during pregnancy and delivery the blood concentrations of these hormones were monitored weekly during the last trimester of pregnancy and at the onset of labour in 15 women, and before and 3 hours after the induction of term delivery in 83 parturients. Neither plasma concentrations of progesterone or estradiol nor the ratio of progesterone to estradiol changed significantly during the last trimester of pregnancy or at the onset of delivery. After the induction of delivery parturients with initial progesterone dominance (ratio of progesterone to estradiol higher than 5 before induction) demonstrated a significant fall in serum concentration of progesterone and in the ratio of progesterone to estradiol while estradiol concentration rose significantly. In estrogen dominant women (progesterone to estradiol ratio equal to or lower than 5) the serum concentration of progesterone and the ratio of progesterone to estradiol rose significantly during the 3 hours after the induction of delivery. Our results suggest that the peripheral blood levels of progesterone and estradiol do not correlate with the tissue biochemical changes which prepare the uterine cervix and myometrium for delivery. The observation that the ratio of progesterone to estradiol decreased in progesterone-dominant and increased in estrogen-dominant women stresses the importance of a well balanced equilibrium of these hormones for prostaglandin metabolism during human delivery.     

The effect of smoking on serum progesterone, estradiol, and luteinizing hormone levels over a menstrual cycle in normal women

Since smoking has been shown to affect serum progesterone and estradiol levels in postmenopausal women, we evaluated the levels of these hormones and luteinizing hormone (LH) over an entire menstrual cycle (17 points) in eight healthy nonsmokers and eight healthy smokers. The total length of the cycle and the lengths of the follicular and luteal phases did not differ between the groups. There was no difference in estradiol, progesterone, or LH levels during the periovulatory and luteal phases. Follicular-phase serum progesterone, which had a level 37% higher in smokers, showed a plateau in both groups (28.3 +/- 5.7 ng/dl versus 20.7 +/- 5.7; P less than 0.0001). Follicular-phase serum estradiol showed a rising curve in both groups. The mean value in smokers was slightly higher than that in nonsmokers (107 pg/ml versus 95; P approximately 0.05); during the early part of the follicular phase, prior to the rapid preovulatory increase, the difference was greater (23%) and of higher statistical significance (80 pg/ml versus 65; P less than 0.001). The follicular-phase LH levels of smokers were skewed downward from the levels in nonsmokers, presumably by negative feedback from the elevated estradiol and progesterone levels; the difference was significant (P less than 0.001). The elevations of serum progesterone and estradiol in smokers probably represent activation of adrenocortical secretion by smoking. The greater and more clear-cut rise of progesterone than of estradiol is probably due to the fact that essentially all of the follicular-phase serum progesterone is secreted by the adrenal, while only part of the follicular-phase serum estradiol comes from the adrenal (via androstenedione and estrone).     

Follicular and steroid hormone changes in Arabian mares in the postpartum period

In this study, the aim has been to characterize the profiles of progesterone, estradiol and follicular changes during postpartum period from parturition to first postpartum ovulation. Jugular venous blood was taken daily for progesterone and estradiol assay until first postpartum ovulation. The diameters of the follicles of the ovaries were recorded. The mean progesterone and estrogen concentrations markedly decreased (p<0.05) during the 48h after parturition. No correlation was observed between estradiol concentrations and the diameter of the largest follicle whereas a negative correlation was present between the number of follicles smaller than 20mm and the number of follicles larger than 20mm on the third and fourth days after postpartum.     

The effect of estradiol and progesterone application on leptin concentration in ovariectomized rats

The aim of the present study was to investigate the effects of estradiol and progesterone application on leptin secretion in ovariectomised rats. The study included 30 adult female Sprague-Dawley rats. Rats were divided into three groups as follows: Group 1; Sham ovariectomy group (n=10), Group 2; Ovariectomy group (n=10), Group 3; Ovariectomized and estradiol propionate (450 microg/kg rat) and medroxyprogesterone acetate (15 mg/kg rat) supplemented group (n=10). One week after ovariectomy, rats in Group 3 were injected estradiol and progesterone for 4 weeks. Twenty-four hours after the last injection, rats were decapitated and blood samples were collected for leptin analysis. Serum leptin levels in Group 2 were found significantly higher than those in Groups 1 and 3 (p<0.01), while those in Group 3 were significantly lower when compared to Group 1 (p<0.0 1). The findings of the present study have shown that ovariectomy led to a significant increase in leptin levels. However, administration of estradiol and progesterone in combination following ovariectomy inhibites increases of leptin levels.     

Estrogen interconversions in the induced cycle in female rhesus monkeys

To determine the extractions and interconversions of estrone and estradiol across and within the uterus, [3H]estradiol and [14C]estrone were infused at a constant rate in six ovariectomized female rhesus (Macaca mulatta) monkeys. Studies were done on Days 9, 14, and 23 of artificial menstrual cycles induced by the timed insertion and removal of Silastic capsules of estradiol and progesterone. Measurements of estrogen radioactivity were made from peripheral arterial blood and uterine venous blood as well as from endometrial biopsy samples. A significant increase occurred in the conversion of estradiol to estrone measured within the uterus on Day 23 compared to Days 9 and 14. The conversion of estrone to estradiol, measured within the uterus, fell progressively from Day 9 to Day 23, but this decrease was not significant. The extractions and interconversions across the uterus, and the overall interconversions of estrone and estradiol were not significantly different on Days 9, 14, or 23 of the cycle. Thus, we have been able to confirm in vivo the increase in the activity of the 17 beta-hydroxysteroid dehydrogenase, the enzyme responsible for estradiol to estrone interconversions, shown earlier by studies done in vitro. However, the increase in 17 beta-hydroxysteroid activity in the uterus is not reflected in the overall interconversions of estrone and estradiol as reflected by measurements in peripheral arterial blood.     

Effects of ovarian hormones on the behavior of captive Macaca fascicularis

To examine the effects of ovarian hormones on the behavior of female Macaca fascicularis and their male partners, daily 1-hr behavior tests were conducted while ovariectomized females were (1) untreated, (2) given estradiol benzoate (EB) (5 μg subcutaneously [s.c.]/day), (3) given estradiol benzoate together with increasing doses of progesterone (P) (5 mg, 10 mg, and 20 mg. s.c./day), and (4) given testosterone propionate (TP) (0.25 mg s.c./day) (six pairs, 540 tests). Weekly blood samples were analyzed by radioimmunoassay for plasma hormone levels (81 samples). Estrogen treatment produced plasma estradiol levels similar to those of intact females during the late follicular phase of the menstrual cycle. Additional progesterone at the lowest dose produced plasma progesterone levels similar to or somewhat higher than those during the midluteal phase, while higher doses produced supraphysiological levels. Androgen treatment resulted in plasma levels well above the physiological range. Hormone treatments produced highly significant effects on the sexual, social, and aggressive interactions of the pairs. As in rhesus monkeys, estrogen increased male and female sexual activity, and increasing doses of additional progesterone reversed these effects. Unlike in rhesus monkeys, testosterone propionate increased both female sexual motivation (invitations) and also male sexual activity and ejaculatory performance. The direction of the hormone-dependent changes in grooming and aggressive interactions confirmed earlier results with intact females and indicated that aggressive interactions and male grooming times were highest, and female grooming times were lowest, when copulatory activity was at its height.     

The effects of progesterone on follicular growth in the rabbit ovary

Studies were undertaken to measure the growth of follicles in the rabbit ovary during periods of elevated blood levels of progesterone. The progestin was increased in the blood by pregnancy or by implantation of progesterone pellets, which raised blood progesterone to near the levels measured during pregnancy. After 1, 2, 3, or 4 weeks of pregnancy or progesterone-pellet treatment, follicles of 1.0 mm external diameter or greater were dissected out of the ovaries and their external diameters were measured; then, each follicle was extracted for measurement of estradiol content. Blood levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured in these animals as well. Follicles up to 2.5 mm in diameter were found in the ovaries of nonpregnant and untreated animals while 1.8 mm was the maximal size found during pregnancy or progesterone-pellet treatment. Furthermore, both in pregnant and in progesterone-treated rabbits, the follicular estradiol content and concentration were significantly suppressed compared to follicles from untreated rabbits. The progesterone pellets had no major effect on the levels of LH and FSH in the blood; the concentration of these gonadotropins in the progesterone-treated rabbits was virtually identical to levels previously measured in the blood of pregnant animals. The results of these studies indicate that progesterone exerts an inhibitory action on follicular development and steroidogenic function in the rabbit ovary. The progesterone action appears to be exerted directly on the ovary and is not indirect, by way of an inhibition of gonadotropin secretion.     

Inhibitory effects of the porcine follicular fluid on estradiol and progesterone secretion by cultured rat granulosa cells

The effect of porcine follicular fluid on estradiol and progesterone secretion was examined using a rat granulosa cell culture with FSH and testosterone in the medium. Follicular fluids from small (less than 5 mm) and large (greater than 6 mm) follicles (SFFI, LFF1) were treated with charcoal, and then fractionated by filtration through an Amicon XM-50 and an PM-10 membrane. The addition of 25% SFF1 and LFF1 into the culture system significantly inhibited estradiol and progesterone secretion (P less than 0.005). These inhibitory activities were observed in PM-10 retentates (10,000-50,000 MW) and filtrates (less than 10,000 MW) of SFF1 and LFF1. The addition of XM-50 filtrates (less than 50,000 MW) of SFF1 and LFF1 caused a dose-dependent inhibition of estradiol and progesterone secretion. The dose-response relationship between the filtrates and estradiol secretion was linear with a significant correlation coefficient. The addition of the filtrates exerted no inhibitory effect on the growth of the cells cultured. XM-50 filtrate of LFF1 from a batch with a low ratio of small/large follicles showed a lower inhibitory activity on estradiol secretion than that of LFF1, while the inhibitory activities in both filtrates on progesterone secretion were almost equivalent. These results suggest that the follicular fluid of small porcine follicle contains nonsteroidal regulators capable of inhibiting estradiol and progesterone secretion by cultured rat granulosa cells, and that the estradiol secretion inhibitor activity decreases in the fluid of large follicle while the progesterone secretion inhibitor activity does not decrease in it.     

A preliminary study of steroid reproductive hormones in human hair

Nowadays research and clinical studies of human reproductive endocrinology are generally carried out using human blood reproductive hormone assays. However the acquisition of human blood samples has some shortcomings. In search of new approaches, we paid attention to the fact that progesterone can be detected in cow's hair. Consequently we investigated whether or not steroid hormones are measurable in human hair. The results showed that the levels of steroid hormones in hair are not affected by shampoo and do not significantly vary between different segments of hair (i.e. top, middle and basal segments). The menstrual estradiol and progesterone rhythm of female hair is similar to that of female serum. The ratio of hair estradiol to serum estradiol in the female is 41.2% and that of hair progesterone to serum progesterone is 59.0%; the ratio of hair testosterone to serum testosterone in male is 116%. There are significant correlations between hair and serum steroid hormones of healthy human adult: γ (estradiol)=0.395 (n=20), p<0.05; γ (progesterone)=0.440 (n=22), p<0.025 and γ (testosterone)=0.395 (n=25), p<0.05.     

Synergism between prolactin and ovarian hormones of DNA synthesis in rats mammary gland.

Autoradiography with [30H] thymedine has been used to measure the rate of DNA synthesis in the mammary epithelium of hypophysectomized-ovariectomized rats under the influence of estradiol, progesterone, and prolactin. Controls and animals treated with estradiol did not increase [3-H] thymidine incorporation, while progesterone alone had a slight stimulatory effect. Prolactin alone stimulated some [3-H] thymidine uptake in ductal and alveolar epithelium, but when combined with either estradiol or progesterone synergistic effects were observed. Estradiol with prolactin stimulated incorporation primarily in the ductal epithelium, whereas progesterone with prolactin stimulated both ductal and alveolar epithelium.     

Suppression of Anti-Candida Activity of Murine Neutrophils by Progesterone In Vitro: A Possible Mechanism in Pregnant Women's Vulnerability to Vaginal Candidiasis

Sex steroid hormones were examined for their effect on mycelial growth of Candida albicans, and the inhibitory activity of casein-induced murine peritoneal neutrophils against mycelial growth of C. albicans was examined in vitro using a crystal violet staining method or a [³H]glucose incorporation method. Four steroid hormones, danazol, estradiol, estriol and testosterone had no effect on mycelial growth of C. albicans, but progesterone appeared to convert the growth form of C. albicans from hyphal to yeast. Danazol (10^–6 m ) and progesterone (10^–5 m ) suppressed anti-Candida activity of neutrophils of non-treated mice, while testosterone, estradiol, and estriol did not. The anti-Candida activity of neutrophils of estradiol-pretreated mice was clearly suppressed by progesterone even at 10^–6 m which corresponded to its plasma concentration in pregnant women in the third trimester. The physiological significance of this suppressive effect of progesterone was discussed in relation to the vulnerability of pregnant women to vaginal candidiasis.     

Regulation of the immunoexpression of aquaporin 9 by ovarian hormones in the rat oviductal epithelium

The volume of oviductal fluid fluctuates during the estrous cycle, suggesting that water availability is under hormonal control. It has been postulated that sex-steroid hormones may regulate aquaporin (AQP) channels involved in water movement across cell membranes. Using a functional assay (oocytes of Xenopus laevis), we demonstrated that the rat oviductal epithelium contains mRNAs coding for water channels, and we identified by RT-PCR the mRNAs for AQP5, -8, and -9, but not for AQP2 and -3. The immunoreactivity for AQP5, -8, and -9 was localized only in epithelial cells of the oviduct. The distribution of AQP5 and -8 was mainly cytoplasmic, whereas we confirmed, by confocal microscopy, that AQP9 localized to the apical plasma membrane. Staining of AQP5, -8, and -9 was lost after ovariectomy, and only AQP9 immunoreactivity was restored after estradiol and/or progesterone treatments. The recovery of AQP9 reactivity after ovariectomy correlated with increased mRNA and protein levels after treatment with estradiol alone or progesterone administration after estradiol priming. Interestingly, progesterone administration after progesterone priming also induced AQP9 expression but without a change in mRNA levels. Levels of AQP9 varied along the estrous cycle with their highest levels during proestrus and estrus. These results indicate that steroid hormones regulate AQP9 expression at the mRNA and protein level and that other ovarian signals are involved in the expression of AQP5 and -8. Thus hormonal regulation of the type and quantity of water channels in this epithelium might control water transport in the oviductal lumen. water channels; epithelial cells; estradiol; progesterone     

Female sex hormones mediate the allergic lung reaction by regulating the release of inflammatory mediators and the expression of lung E-selectin in rats

Background

Fluctuations of estradiol and progesterone levels caused by the menstrual cycle worsen asthma symptoms. Conflicting data are reported in literature regarding pro and anti-inflammatory properties of estradiol and progesterone.

Methods

Female Wistar rats were ovalbumin (OVA) sensitized 1 day after resection of the ovaries (OVx). Control group consisted of sensitized-rats with intact ovaries (Sham-OVx). Allergic challenge was performed by aerosol (OVA 1%, 15 min) two weeks later. Twenty four hours after challenge, BAL, bone marrow and total blood cells were counted. Lung tissues were used as explants, for expontaneous cytokine secretion in vitro or for immunostaining of E-selectin.

Results

We observed an exacerbated cell recruitment into the lungs of OVx rats, reduced blood leukocytes counting and increased the number of bone marrow cells. Estradiol-treated OVx allergic rats reduced, and those treated with progesterone increased, respectively, the number of cells in the BAL and bone marrow. Lungs of OVx allergic rats significantly increased the E-selectin expression, an effect prevented by estradiol but not by progesterone treatment. Systemically, estradiol treatment increased the number of peripheral blood leukocytes in OVx allergic rats when compared to non treated-OVx allergic rats. Cultured-BAL cells of OVx allergic rats released elevated amounts of LTB₄ and nitrites while bone marrow cells increased the release of TNF-α and nitrites. Estradiol treatment of OVx allergic rats was associated with a decreased release of TNF-α, IL-10, LTB₄ and nitrites by bone marrow cells incubates. In contrast, estradiol caused an increase in IL-10 and NO release by cultured-BAL cells. Progesterone significantly increased TNF- α by cultured BAL cells and bone marrow cells.

Conclusions

Data presented here suggest that upon hormonal oscillations the immune sensitization might trigger an allergic lung inflammation whose phenotype is under control of estradiol. Our data could contribute to the understanding of the protective role of estradiol in some cases of asthma symptoms in fertile ans post-menopausal women clinically observed.