Histamine, mast cells and ovarian function

Lymphatic vasculature in ovarian cancer

Ovarian cancer (OVCA) is the second most common gynecological cancer and one of the leading causes of cancer related mortality among women. Recent studies suggest that among ovarian cancer patients at least 70% of the cases experience the involvement of lymph nodes and metastases through lymphatic vascular network. However, the impact of lymphatic system in the growth, spread and the evolution of ovarian cancer, its contribution towards the landscape of ovarian tissue resident immune cells and their metabolic responses is still a major knowledge gap. In this review first we present the epidemiological aspect of the OVCA, the lymphatic architecture of the ovary, we discuss the role of lymphatic circulation in regulation of ovarian tumor microenvironment, metabolic basis of the upregulation of lymphangiogenesis which is often observed during progression of ovarian metastasis and ascites development. Further we describe the implication of several mediators which influence both lymphatic vasculature as well as ovarian tumor microenvironment and conclude with several therapeutic strategies for targeting lymphatic vasculature in ovarian cancer progression in present day.

Mast Cell Activation Syndrome in COVID-19 and Female Reproductive Function: Theoretical Background vs. Accumulating Clinical Evidence

Coronavirus disease 2019 (COVID-19), a pandemic disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, can affect almost all systems and organs of the human body, including those responsible for reproductive function in women. The multisystem inflammatory response in COVID-19 shows many analogies with mast cell activation syndrome (MCAS), and MCAS may be an important component in the course of COVID-19. Of note, the female sex hormones estradiol (E2) and progesterone (P4) significantly influence mast cell (MC) behavior. This review presents the importance of MCs and the mediators from their granules in the female reproductive system, including pregnancy, and discusses the mechanism of potential disorders related to MCAS. Then, the available data on COVID-19 in the context of hormonal disorders, the course of endometriosis, female fertility, and the course of pregnancy were compiled to verify intuitively predicted threats. Surprisingly, although COVID-19 hyperinflammation and post-COVID-19 illness may be rooted in MCAS, the available clinical data do not provide grounds for treating this mechanism as significantly increasing the risk of abnormal female reproductive function, including pregnancy. Further studies in the context of post COVID-19 condition (long COVID), where inflammation and a procoagulative state resemble many aspects of MCAS, are needed.

Bilateral asymmetry in bullfrog testes and fat bodies: correlations with steroidogenic activity, mast cells number and structural proteins

In seasonal breeders, such as amphibians, testicular functions depend on complex processes that change according to seasonality, including Leydig cell (LC) differentiation and lipid-dependent steroidogenesis, extracellular proteins remodeling and actin-dependent cellular dynamics. Speculating that fat bodies (FB) could support some of these processes in L. catesbeianus, we evaluated bilaterally the FB weights, correlating them to testicular parameters such as weight, testosterone (T) immunoexpression, mast cells (MC) number, vascularization and structural proteins. In an attempt to better understand the testicular asymmetry in amphibians, correlations between these different testicular parameters were also established. Right testes (RT), left testes (LT) and associated FB of bullfrogs were weighed, and testes were processed for light and transmission electron microscopy. Collagen content (COL) and MC number were quantified. T and actin immunoexpressions and vascular areas were measured. Statistical analyses and Pearson's correlation were performed. The LT and its associated FB were heavier than the right ones, and showed intense T and actin immunoexpressions, numerous lipid-rich LC, and greater MC number, COL and vascularization than the RT. Positive correlations were detected between: a) FB and testis weights, b) T immunoexpression and testis and FB weights, c) T and actin immunoexpressions and COL. Otherwise, MC number was inversely correlated to T immunoexpression and COL. In right and left sides, the proportional correlation between T immunoexpression and FB weight suggests that FB-stored lipid amount depends on the steroidogenic demand of its associated testis. Thus, the asymmetry in the testes and FB may be associated, at least in part, to the LC steroidogenic activity, which tends to be more intense in LT than in RT. The results also point to a role of COL and mast cells in the LC differentiation and steroidogenesis. Actin was also greater in LT and correlated with T immunoexpression, indicating that the amount of this structural protein depends on androgenic control. Therefore, the testicular asymmetry in bullfrogs seems to be associated to different morphofunctional processes occurring, bilaterally, at different intensities. In this case, there is a tendency of LT, in association with its FB, to be more active than RT. The findings highlight the FB-testis interplay for the comprehension of reproduction in amphibians.

Male and female gonadal ageing: its impact on health span and life span

Ageing is linked to changes in the hypothalamic-pituitary-gonadal axis and a progressive decline in gonadal function. While women become infertile when they enter menopause, fertility decline in ageing men does not necessarily involve a complete cessation of spermatogenesis. Gonadal dysfunction in elderly people is characterized by morphological, endocrine and metabolic alterations affecting the reproductive function and quality of life. With advancing age, sexuality turns into a critical emotional and physical factor actually defining the number of years that ageing people live a healthy life. Gonadal ageing correlates with comorbidities and an increased risk of age-related diseases including diabetes, kidney problems, cardiovascular failures and cancer. This article briefly summarizes the current state of knowledge on ovarian and testicular senescence, explores the experimental models used in the study of gonadal ageing, and describes the local pro-inflammatory, oxidative and apoptotic events and the associated signalling pathways that take place in the gonads while people get older. Overall, literature reports that ageing exacerbates a mutual crosstalk among oxidative stress, apoptosis and the inflammatory response in the gonads leading to detrimental effects on fertility. Data also highlight the clinical implications of novel therapeutic interventions using antioxidant, anti-apoptotic and anti-inflammatory drugs on health span and life span.

Immune and vascular contributions to organogenesis of the testis and ovary

Gonad development is a highly regulated process that coordinates cell specification and morphogenesis to produce sex-specific organ structures that are required for fertility, such as testicular seminiferous tubules and ovarian follicles. While sex determination occurs within specialized gonadal supporting cells, sexual differentiation is evident throughout the entire organ, including within the interstitial compartment, which contains immune cells and vasculature. While immune and vascular cells have been traditionally appreciated for their supporting roles during tissue growth and homeostasis, an increasing body of evidence supports the idea that these cell types are critical drivers of sexually dimorphic morphogenesis of the gonad. Myeloid immune cells, such as macrophages, are essential for multiple aspects of gonadogenesis and fertility, including for forming and maintaining gonadal vasculature in both sexes at varying stages of life. While vasculature is long known for supporting organ growth and serving as an export mechanism for gonadal sex steroids in utero, it is also an important component of fetal testicular morphogenesis and differentiation; additionally, it is vital for ovarian corpus luteal function and maintenance of pregnancy. These findings point toward a new paradigm in which immune cells and blood vessels are integral components of sexual differentiation and organogenesis. In this review, we discuss the state of the field regarding the diverse roles of immune and vascular cells during organogenesis of the testis and ovary and highlight outstanding questions in the field that could stimulate new research into these previously underappreciated constituents of the gonad.

Mast cells and cancer

Mast cells (MCs) are a potent proangiogenic factor in tumors, they product several pro-angiogenic factors such as fibroblast growth factor 2 (FGF-2), vascular epithelial growth factor (VEGF), tryptase and chymase. Tryptase is a serine protease classified as α-tryptase and β-tryptase, both produced by MCs. Tryptase degrades the tissues, playing an important role in angiogenesis and in the development of metastases. Serum tryptase increases with age, with increased damage to cells and risk of developing a malignancy and it could be considered the expression of a fundamental role of MCs in tumor growth or, on the contrary, in the antitumor response. Many biomarkers have been developed in clinical practice for improving diagnosis and prognosis of some neoplasms. Elevated tryptase levels are found in subgroups of patients with haematologic and solid cancers. In the current review, we want to update the perspectives of tryptase as a potential biomarker in daily practice in different neoplasms.

Cresyl Violet Stains Mast Cells Selectively: Its Application to Counterstaining in Immunohistochemistry

The thiazine dye toluidine blue (TB) is well known to stain mast cells and hyaline cartilage metachromatically, and thus is mostly often used for their identification. However, TB is not suitable for counterstaining in immunohistochemistry, because of its high-background staining in the cytoplasm of other cell species and in extracellular structures. To expand the knowledge about dyestuffs staining mast cells in consideration with their usage in immunohistochemistry, we determined the stainability of several thiazines and oxazines, which are structurally related compounds to TB, using sections of mast cell-containing tissues. We found that all azine dyes used metachromatically stained mast cells and cartilage. Among these dyes, an oxazines cresyl violet (CV) stained mast cells with lower background, suggesting that those are useful for detecting mast cells and for counterstaining in immunohistochemistry. To ascertain its utility, CV was used in immunostaining of bHSDs in sections from adult rat ovary. Immunopositive signals reflected by DAB development in brown were clearly detected even after CV staining. We conclude that, similar to thiazines, oxazines stain mast cells metachromatically, and that of these, CV is more useful as a counterstain in immunohistochemistry than TB.

Extragonadal oocytes residing in the mouse ovarian hilum contribute to fertility

The observation of pups born from recipient and donor mice after ovariectomy followed by ovarian transplant poses the interesting possibility of an extraovarian source of oocytes. However, whether mammalian adult oocytes reside in extragonadal tissues remains elusive. Using transgenic fluorescent reporter mice and transplantation surgeries, we demonstrate the presence of both donor- and recipient-derived corpora lutea and recovery of both donor- and recipient-derived offspring from ovariectomized mice after transplantation of donor ovaries. A potential region for extraovarian oocytes is the hilum, a ligament-like structure between the ovary and the reproductive tract. Immunofluorescent confocal microscopy of mouse ovaries and reproductive tracts revealed that a population of primordial follicles resides outside the ovary within the hilum. Ovariectomy-only controls confirmed that oocytes remain in the recipient hilum after surgery. These results provide evidence that the hilum is a reserve source of follicles, which likely return to the ovary for maturation and ovulation. By identifying a new follicle reservoir, our study addresses a long-standing question in reproductive biology and contributes to new conceptual knowledge about ovarian function and fertility.

Spatial distribution of mast cells around vessels and glands in human gastric carcinoma

The spatial distribution of mast cells inside the tumor stroma has been little investigated. In this study, we have evaluated tumor mast cells (MCs) distribution in gastric cancer through the analysis of the morphological features of the spatial patterns generated by these cells, including size, shape, and architecture of the cell pattern. The pattern of distribution of tryptase- and chymase-positive MCs around the blood vessels and gastric glands in human gastric adenocarcinoma samples was investigated by immunohistochemical techniques and by introducing a quantitative approach to characterize the spatial distribution of MCs. In human gastric cancer, both chymase-positive MC and vessels exhibited significant deviations from randomness for what it concerns their spatial relationship with gastric parenchyma. As indicated by cell-to-gland distances shorter than expected by chance, in grade II samples a preferential localization of chymase-positive MC near the gastric glands was observed. Interestingly, the same type of spatial association was exhibited by vessels in grade IV samples, where vessel-to-gland distances shorter than expected by chance were observed. These two findings allow to speculate about a sequence of events in which a subpopulation of MC is first recruited around gastric parenchyma to drive the subsequent development of a vascular support to the tissue.

Non-random spatial relationships between mast cells and microvessels in human endometrial carcinoma

Mast cells (MCs) accumulate in the stroma surrounding tumors, where they secrete angiogenic cytokines and proteases, and an increased number of MCs have been demonstrated in angiogenesis associated with solid and hematological tumors. The aim of this study is to contribute to the knowledge of distribution of MCs in tumors, investigating the pattern of distribution of tryptase-positive MCs around the blood vessels in human endometrial carcinoma samples by introducing a quantitative approach to characterize their spatial distribution. The results have shown that in human endometrial cancer bioptic specimens the spatial distribution of MCs shows significant deviation from randomness as compared with control group in which, instead, the spatial distribution of MCs is consistent with a random distribution. These findings confirm that MCs enhance tumor angiogenesis and their preferential localization along blood vessels and sites of new vessel formation sustaining the suggestion for an association between MCs and angiogenesis. However, this spatial association between vessels and MCs might simply reflect migrating MCs from the blood stream at vessel growing sites.

Relationship between numerous mast cells and early follicular development in neonatal MRL/MpJ mouse ovaries

In the neonatal mouse ovary, clusters of oocytes called nests break into smaller cysts and subsequently form individual follicles. During this period, we found numerous mast cells in the ovary of MRL/MpJ mice and investigated their appearance and morphology with follicular development. The ovarian mast cells, which were already present at postnatal day 0, tended to localize adjacent to the surface epithelium. Among 11 different mouse strains, MRL/MpJ mice possessed the greatest number of ovarian mast cells. Ovarian mast cells were also found in DBA/1, BALB/c, NZW, and DBA/2 mice but rarely in C57BL/6, NZB, AKR, C3H/He, CBA, and ICR mice. The ovarian mast cells expressed connective tissue mast cell markers, although mast cells around the surface epithelium also expressed a mucosal mast cell marker in MRL/MpJ mice. Some ovarian mast cells migrated into the oocyte nests and directly contacted the compressed and degenerated oocytes. In MRL/MpJ mice, the number of oocytes in the nest was significantly lower than in the other strains, and the number of oocytes showed a positive correlation with the number of ovarian mast cells. The gene expression of a mast cell marker also correlated with the expression of an oocyte nest marker, suggesting a link between the appearance of ovarian ? 4mast cells and early follicular development. Furthermore, the expression of follicle developmental markers was significantly higher in MRL/MpJ mice than in C57BL/6 mice. These results indicate that the appearance of ovarian mast cells is a unique phenotype of neonatal MRL/MpJ mice, and that ovarian mast cells participate in early follicular development, especially nest breakdown.

Gene expression networks underlying ovarian development in wild largemouth bass (Micropterus salmoides)

Background

Oocyte maturation in fish involves numerous cell signaling cascades that are activated or inhibited during specific stages of oocyte development. The objectives of this study were to characterize molecular pathways and temporal gene expression patterns throughout a complete breeding cycle in wild female largemouth bass to improve understanding of the molecular sequence of events underlying oocyte maturation.

Methods

Transcriptomic analysis was performed on eight morphologically diverse stages of the ovary, including primary and secondary stages of oocyte growth, ovulation, and atresia. Ovary histology, plasma vitellogenin, 17β-estradiol, and testosterone were also measured to correlate with gene networks.

Results

Global expression patterns revealed dramatic differences across ovarian development, with 552 and 2070 genes being differentially expressed during both ovulation and atresia respectively. Gene set enrichment analysis (GSEA) revealed that early primary stages of oocyte growth involved increases in expression of genes involved in pathways of B-cell and T-cell receptor-mediated signaling cascades and fibronectin regulation. These pathways as well as pathways that included adrenergic receptor signaling, sphingolipid metabolism and natural killer cell activation were down-regulated at ovulation. At atresia, down-regulated pathways included gap junction and actin cytoskeleton regulation, gonadotrope and mast cell activation, and vasopressin receptor signaling and up-regulated pathways included oxidative phosphorylation and reactive oxygen species metabolism. Expression targets for luteinizing hormone signaling were low during vitellogenesis but increased 150% at ovulation. Other networks found to play a significant role in oocyte maturation included those with genes regulated by members of the TGF-beta superfamily (activins, inhibins, bone morphogenic protein 7 and growth differentiation factor 9), neuregulin 1, retinoid X receptor, and nerve growth factor family.

Conclusions

This study offers novel insight into the gene networks underlying vitellogenesis, ovulation and atresia and generates new hypotheses about the cellular pathways regulating oocyte maturation.

Distribution and heterogeneity of mast cells in female reproductive tract and ovary on different days of the oestrus cycle in Angora goats

The physiological distribution of mast cells (MCs) in the reproductive tract and ovary of 12 Angora goats was determined using light microscopic histochemical techniques. Uterus (corpus uteri and cornu uteri), uterine cervix, uterine tubes (isthmus and ampulla) and ovary samples were obtained by laparatomy from groups of animals during metoestrus, dioestrus and proestrus (days 5, 10 and 16 of the oestrous cycle). Tissues were fixed in Mota's fixative (basic lead acetate) for 48 h and embedded in paraffin. Six-micrometre-thick sections were stained with toluidine blue in 1% aqueous solution at pH 1.0 for 5 min and alcian blue-Safranin at pH 1.0 for 30 min. MCs were generally associated with blood vessels in all reproductive organs. In the uterus, they were concentrated mainly in the close of the uterine gland and deep stroma in the endometrium. Higher MC numbers were observed by toluidine blue staining in the uterus, uterine cervix and uterine tubes on days 10 (corpus uterine: 4.7 +/- 3.8 and cornu uterine: 4.9 +/- 3.5) and 16 (corpus uterine: 5.9 +/- 4.5 and cornu uterine: 5.4 +/- 2.4) of the oestrous cycle compared with day 5 (p < 0.05). Mast cells were not observed in the follicles, the corpus luteum and the underside of the surface epithelium of the ovarian cortex, but were observed in the interstitial cortical stroma and the ovarian medulla. In the ovary, MC numbers were significantly higher on day 16 of the oestrous cycle (cortex: 3.4 +/- 2.4 and medulla: 5.7 +/- 4.5, p < 0.05). Safranin-positive connective tissue MCs were not observed in the uterine tube on any occasion. These results indicate oestrous cycle-related changes in the number and location of MCs in goat reproductive organs.

Intratesticular morphometric, cellular and endocrine changes in dromedary bulls exhibiting azoospermia

Twenty bulls, aged 7-12 years and selected from six dromedary farms were used in this study. Fifteen previously fertile animals were divided into fertile (controls) and infertile groups on the basis of abnormal scrotal contents following palpation and azoospermic ejaculates collected by electroejaculation. An examination of the clinical and histological findings as well as the testicular patterns of oestradiol-17beta, testosterone and histamine indicated that three bulls displayed normal ranges comparable to the controls but with bilateral spermatocoeles in the caput epididymides in conjunction with the soft texture of the testicles. Seven bulls showed moderate testicular firmness and springiness, a marked increase in testicular oestradiol-17beta and histamine concentrations, and increases in surface area, density of mast cells and percentages of seminiferous tubules containing premeiotic spermatogenic cells as well as decreases in testicular testosterone concentrations, surface area of Leydig cells and diameter of the seminiferous tubules. The remaining five infertile animals had small hard testicles, supranormal testicular testosterone concentrations, baseline values of testicular oestradiol-17beta and histamine, decreased numbers of Sertoli and mast cells, with a predominance (98.2%) of seminiferous tubules containing spermatogonia resting on a thickened tubular basement membrane. The results provide information on the relationship between gonadotrophin, testicular oestrogen, androgens and histamine as well as spermatogenesis in normal and azoospermic dromedary bulls.

Effects of indomethacin on ovarian leukocytes during the periovulatory period in the rat

We have investigated the effects of indomethacin (IM), a non-steroidal anti-inflammatory drug, and the role of prostaglandins on the accumulation of leukocytes in the rat ovary during the periovulatory period. Adult cycling rats were injected sc with 1 mg of IM in olive oil or vehicle on the morning of proestrus. Some animals were killed at 16:00 h in proestrus. On the evening (19:00 h) of proestrus, IM-treated rats were injected with 500 micrograms of prostaglandin E1 in saline or vehicle. Animals were killed at 01:30 and 09:00 h in estrus. There was an influx of macrophages, neutrophils, and eosinophils into the theca layers of preovulatory follicles, and of neutrophils and eosinophils into the ovarian medulla from 16:00 h in proestrus to 01:30 h in estrus. All these changes, except the accumulation of neutrophils in the theca layers of preovulatory follicles, were blocked by IM treatment. At 09:00 h in estrus, large clusters of neutrophils were observed in IM-treated rats, around abnormally ruptured follicles. The accumulation of leukocytes was not restored by prostaglandin supplementation, despite the inhibition of abnormal follicle rupture and restoration of ovulation in these animals. These results suggest that different mechanisms are involved in leukocyte accumulation in the ovary during the periovulatory period, and that the inhibitory effects of IM on the influx of leukocytes are not dependent on prostaglandin synthesis inhibition.

Ultrastructure and distribution of interstitial glandular cells and associated elements in human fetal ovaries

In order to understand the fine structure and distribution of the interstitial glandular cells (IGCs) and associated elements in the human fetal ovary, we studied human fetal ovaries at 16 weeks post fertilization (p. f.) by transmission electron microscopy. Semithin sections revealed voluminous typical IGCs usually grouped in clusters, located in the interstitium among the ovigerous cords. Isolated primordial follicles were seen in the cords located close to the interstitium in which IGCs were present. Besides the main ultrastructural characteristics of steroid secreting cells, the IGCs showed lipofuscin granules and stacks of annulate lamellae in their cytoplasm. Fibrocytes, macrophages and mast cells were detected close to the IGCs. In particular, the fibrocytes were located around the IGCs, with which they occasionally formed focal cell contacts. Fibrocytes issued numerous long projections, which, together with collagen fibers, surrounded the clusters of IGCs and small vessels (mainly capillaries), often extending into the intercellular spaces among IGCs. These data indicated that, already at the initiation of folliculogenesis, the IGCs are present numerously in a close association with the ovigerous cords. The morphological aspects of IGCs were comparable to that of fetal testis interstitial (Leydig) cells and hilar cells in adult ovary, and suggest that fetal IGCs may be source of adult ovary hilar cells. In addition, we have here demonstrated for the first time that IGCs are associated with stromal cells whose distribution seems to support IGCs microtopography. Fetal ovarian fibrocytes revealed a structural arrangement similar to that of the "compartmentalizing cells" previously described in the adult testis. Macrophages and mast cells presumably have a role as local modulators of steroid synthesis. Mast cells may also affect fibrocyte organization and vascular permeability. We thus suggest that IGCs and associated cells may form a glandular unit in the human fetal ovary similar to that in the adult testis, and this structure is likely involved in early steroid secretion during gonadal differentiation.

Effect of single and compound knockouts of estrogen receptors alpha (ERalpha) and beta (ERbeta) on mouse reproductive phenotypes

The functions of estrogen receptors (ERs) in mouse ovary and genital tracts were investigated by generating null mutants for ERalpha (ERalphaKO), ERbeta (ERbetaKO) and both ERs (ERalphabetaKO). All ERalphaKO females are sterile, whereas ERbetaKO females are either infertile or exhibit variable degrees of subfertility. Mast cells present in adult ERalphaKO and ERalphabetaKO ovaries could participate in the generation of hemorrhagic cysts. Folliculogenesis proceeds normally up to the large antral stage in both ERalphaKO and ERbetaKO adults, whereas large antral follicles of ERalpha+/−ERbetaKO and ERalphabetaKO adults are markedly deficient in granulosa cells. Similarly, prematurely developed follicles found in prepubertal ERalphaKO ovaries appear normal, but their ERalphabetaKO counterparts display only few granulosa cell layers. Upon superovulation treatment, all prepubertal ERalphaKO females form numerous preovulatory follicles of which the vast majority do not ovulate. The same treatment fails to elicit the formation of preovulatory follicles in half of the ERbetaKO mice and in all ERalpha+/−/ERbetaKO mice. These and other results reveal a functional redundancy between ERalpha and ERbeta for ovarian folliculogenesis, and strongly suggest that (1) ERbeta plays an important role in mediating the stimulatory effects of estrogens on granulosa cell proliferation, (2) ERalpha is not required for follicle growth under wild type conditions, while it is indispensable for ovulation, and (3) ERalpha is also necessary for interstitial glandular cell development. Our data also indicate that ERbeta exerts some function in ERalphaKO uterus and vagina. ERalphabetaKO granulosa cells localized within degenerating follicles transform into cells displaying junctions that are unique to testicular Sertoli cells. From the distribution pattern of anti-Mullerian hormone (AMH) in ERalphabetaKO ovaries, it is unlikely that an elevated AMH level is the cause of Sertoli cell differentiation. Our results also show that cell proliferation in the prostate and urinary bladder of old ERbetaKO and ERalphabetaKO males is apparently normal.

Morphology of the Harderian gland of the Gecko, Tarentola mauritanica

The Harderian gland of the gecko, Tarentola mauritanica, was studied at the histological, histochemical, and ultrastructural levels. It is a nonlobate compound acinar gland surrounded by a thin capsule of connective tissue. Numerous connective tissue-type mast cells, ultrastructurally similar to those described in other higher vertebrates, were identified in the interstitial tissue between the acini. Pyramidal or columnar-shaped secretory glandular cells were observed in the acini. In the glandular cells, two types of structures could be distinguished on the basis of their high or low electron density. Lipid droplets were found in the cytoplasm of the Harderian gland of both sexes. Histochemical tests showed that the Harderian gland of the gecko is a seromucous gland. The secretion is essentially merocrine, although an apocrine type of secretion is sometimes observed.

Granulocyte-macrophage colony-stimulating factor enhances interleukin-1beta stimulated histamine release in the preovulatory rat ovary

The existence of immune cells including macrophages and mast cells in rat ovary implies that various cytokines from these cells may play a role in ovarian functions. The aim of the present study was to investigate whether granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-1beta are capable of stimulating histamine release and steroidogenesis in rat ovary, and to determine the sites of histamine production in the ovary. Histamine release from preovulatory ovarian tissues was stimulated in a dose-dependent manner at 3-30 ng/ml of GM-CSF in the presence of interleukin-1beta (10 ng/ml). However, treatment with GM-CSF and interleukin-1beta did not cause any significant change in the levels of ovarian steroids. Intense staining of histidine decarboxylase in the ovary was immunohistochemically detected in large granular cells on the morning of the pro-oestrus day. These results indicate that GM-CSF may be involved in the regulation of ovarian histamine secretion in mast cells partially by enhancing interleukin-1beta-induced histamine release in the process of ovulation.

Distribution of histamine in laying hen ovary

In a laying hen, histamine was found to be present in all compartments of the ovary, i.e. stroma with follicles < 1 mm, small white (1-4 mm), large white (4-8 mm), atretic white, yellow preovulatory (8-35 mm) and postovulatory follicles. Stroma containing non-yolky follicles exhibited the highest histamine concentration (6080 +/- 331 ng/g wet wt. tissue) which differed significantly (P < 0.01) from histamine levels observed in all examined classes of ovarian follicles. High histamine concentration was found in small, large and atretic white follicles as well as in older postovulatory follicles whereas low levels of histamine contained yellow preovulatory and younger postovulatory follicles. Population of yolky white follicles presented significant (P < 0.01) differences in histamine level among small (4280 +/- 333), atretic (2940 +/- 193) and large (2010 +/- 110 ng/g) follicles. Within hierarchy of yellow preovulatory (F7-F1) follicles initial decrease in histamine concentration, from 859.3 +/- 51.5 ng/g in F7 follicle to 363.9 +/- 28.3 ng/g in F4 follicle, was followed by the increase as follicle matured, reaching the highest level in F1 follicle (711.4 +/- 35.9 ng/g). In postovulatory (P1-P5) follicles histamine concentration gradually increased as they were getting older, from 604.3 +/- 49.3 ng/g in P1 follicle to 2253 +/- 197 ng/g in P5 follicle. Determination of histamine in relation to ovulation revealed significant (P < 0.01) difference both in histamine concentration and content between the largest preovulatory F1 follicle and the largest postovulatory P1 follicle, being 0.5 h before and 0.5 h after ovulation, respectively. It is suggested that in chicken, ovarian histamine may play a role in the follicular development and/or the ovulatory process.

Mast cells can secrete vascular permeability factor/ vascular endothelial cell growth factor and exhibit enhanced release after immunoglobulin E-dependent upregulation of fc epsilon receptor I expression

Vascular permeability factor/vascular endothelial cell growth factor (VPF/VEGF) can both potently enhance vascular permeability and induce proliferation of vascular endothelial cells. We report here that mouse or human mast cells can produce and secrete VPF/VEGF. Mouse mast cells release VPF/VEGF upon stimulation through Fcepsilon receptor I (FcepsilonRI) or c-kit, or after challenge with the protein kinase C activator, phorbol myristate acetate, or the calcium ionophore, A23187; such mast cells can rapidly release VPF/VEGF, apparently from a preformed pool, and can then sustain release by secreting newly synthesized protein. Notably, the Fc epsilonRI-dependent secretion of VPF/VEGF by either mouse or human mast cells can be significantly increased in cells which have undergone upregulation of Fc epsilonRI surface expression by a 4-d preincubation with immunoglobulin E. These findings establish that at least one cell type, the mast cell, can be stimulated to secrete VPF/VEGF upon immunologically specific activation via a member of the multichain immune recognition receptor family. Our observations also identify a new mechanism by which mast cells can contribute to enhanced vascular permeability and/or angiogenesis, in both allergic diseases and other settings.

Ovarian immune cells express granulocyte-macrophage colony-stimulating factor (GM-CSF) during follicular growth and luteinization in gonadotropin-primed immature rodents

To obtain clues as to whether granulocyte-macrophage colony-stimulating factor (GM-CSF) is related to ovarian physiology, the sites, the gene expression and the production of GM-CSF in the ovary during follicular development and luteinization were studied in equine CG (eCG)-primed immature mice and rats. During follicular development, the expression of GM-CSF mRNA was localized in theca-interstitial tissues, oocytes and granulosa cells of small developing follicles in mice. In the mouse ovary after ovulation, luteal tissues as well as the above components had intense signals for GM-CSF mRNA. Mast cells, which were present mainly in the ovarian medulla, also expressed mRNA for GM-CSF in rats. Immunohistochemical analyses with two different antibodies against murine GM-CSF revealed that GM-CSF-like immunoreactivity was detectable mainly in theca-interstitial, luteal tissues, oocytes and mast cells. Intense GM-CSF positive cells in theca-interstitial and luteal tissues were stained with anti-CD11b antibody in mice. Messenger RNAs for GM-CSF receptor subunits were expressed in mast cells of the medulla and in luteal tissues in rat ovary. The levels of GM-CSF released into the culture media by rat ovarian dispersed cells 1-2 days after eCG treatment were higher than those before the treatment, although no significant change in the levels of ovarian GM-CSF mRNA was detected by reverse transcription-polymerase chain reaction analysis. The secretion of GM-CSF was also increased by treatment of the cells with immune stimulators such as phorbol ester, interleukin-1 and lipopolysaccharide. These data indicate that ovarian macrophages and mast cells in addition to theca-interstitial cells, synthesize and release GM-CSF during ovarian cycles, and that ovarian GM-CSF secreting capacity is enhanced during early stages of follicular development in rodents.

Ovarian, uterine and brain mast cells in female rats: cyclic changes and contribution to tissue histamine

Using histochemical techniques, we determined mast cell content in ovarian, uterine and brain tissues throughout the estrus cycle of the rat. In one series of experiments, 26 cycling female rats were used for the measurement of follicle stimulating hormone (FSH) in plasma and evaluation of mast cells in the tissues. In a second series, cycling female rats were used for the determination of tissue histamine. The number, degranulation pattern and staining characteristics of mast cells changed synchronously in rat ovarian, uterine and brain tissues during the estrus cycle. A great majority of mast cells in tissues were stained by Alcian blue at proestrus and metestrus. Safranin-stained mast cells were abundant in all tissues during estrus and diestrus. Alcian blue-stained mast cells contribute to the change of tissues histamine level. In ovarian tissue, histamine level increased significantly at proestrus and metestrus. The lowest ovarian histamine level was determined at estrus, in which virtually all mast cells were stained by safranin only. Mast cells in ovarian, uterine and brain tissues seem to change their histamine content throughout the estrus cycle. Mast cells are absent from the thalamus during proestrus and are present in the hypothalamus only during the estrus phase. Plasma FSH concentrations (mlU ml-1) did not significantly change throughout the estrus cycle (proestrus: 0.81 +/- 0.11, estrus: 0.69 +/- 0.07, metestrus: 0.82 +/- 0.13, diestrus: 0.67 +/- 0.19).

Number of mast cells in the Harderian gland of the lizard Podarcis sicula sicula (Raf): the annual cycle and its relation to environmental factors and estradiol administration

The Harderian gland of the lizard Podarcis sicula sicula (Raf) contains connective tissue type mast cells whose numbers vary during the year showing two peaks, one in spring the other in winter. No sex differences are found throughout the year. Thermal and photoperiodic manipulations indicate that only temperature influences mast cell number (MCN) both in winter and in summer but not in spring. In animals exposed to high temperatures in February (but not in May) MCN declined, while exposure to low temperature in July had the opposite effect. Estradiol treatment of the February and April lizards increased MCN, an effect counteracted by the synthetic antiestrogen tamoxifen; in July lizards, this did not occur. In animals exposed to a high temperature in February, estradiol had no effect, as in animals exposed to low temperatures in July. These data suggest that in spring MCN seems to be more responsive to hormonal stimuli rather than external cues (temperature), while in summer MCN is more sensitive to temperature than to hormonal stimuli (estradiol). Both humoral and external factors are concluded to influence mast cell numbers in the Harderian gland of the lizard P. sicula sicula.

Immunological aspects of ovarian function: role of the cytokines

Interaction between the immune system and reproduction is multiple. Either directly or indirectly through their products, immune cells are associated with the regulation of every level of the hypothalamus-pituitary-ovarian axis. Immune cells are present in the ovaries and their numbers increase during the cycle. During the follicular development cytokines assist granulosa cell growth while inhibiting their differentiation. During the LH peak, an influx of immune cells occurs and several cytokines are released. The rupture of the follicle is considered as an inflammatory reaction. IL-1, TNF-alpha are the main cytokines involved in this process. During the luteal phase, the installation of the corpus luteum needs the setting up of neovascularization. Cytokines are probable candidates for this function, but they also promote cellular differentiation resulting in steroid synthesis. In the absence of pregnancy T lymphocytes and eosinophils are involved in corpus luteum regression. Their products are directly cytotoxic for the luteal cells. They attract macrophages which are locally activated to phagocytose the damaged luteal cells. They can induce apoptosis of endothelial and luteal cells through gene expression. Cytokines are members of a larger regulatory network residing in the ovary and involving hormones and growth factors. The various stages of ovarian cycle will be shown from an immunological point of view. Understanding the role of the cytokines should enable us to go beyond a purely descriptive stage, and allow us to envisage new ovulation induction therapy and treatment in certain cases of premature menopause.

Mast cell-Leydig cell relationships in the testis of the lizard Podarcis s. sicula Raf: thermal manipulation, ethane 1,2-dimethane sulphonate (EDS) and sex hormone treatment

Mast cells of connective tissue type are scattered in the interstitial compartment of the lizard Podarcis s. sicula. Their number varies during the year, showing peaks in spring and in winter, respectively. Thermal manipulation affects mast cell number (MCN): high temperature decreased MCN in both January and May, while low temperature increased MCN only in January. Ethane dimethane sulphonate, a toxin which specifically destroys Leydig cells, induced an increase in MCN on days 3 and 7 of treatment. Oestradiol treatment provoked a strong increase in MCN that was blocked by tamoxifen. Blocking androgen receptors with cyproterone acetate resulted in an increase in MCN, while testosterone injection provoked a strong decrease. These results suggest a relationship between the presence of mature Leydig cells and mast cell proliferation and/or differentiation.

Number and state of rat ovarian mast cells after exogenous administration of luteinizing hormone

Diestrous rats were treated with an injection of luteinizing hormone (LH), and their ovaries were examined for mast cell number and stage of degranulation at 2 and 4 hr post-injection. LH tripled the number of medullary mast cells at 2 hr. The source or origin of the additional mast cells is unknown. Comparison of the present results with other studies of rat ovarian mast cell dynamics suggests the occurrence of a reduction in mast cell number in early to mid-proestrus followed by an LH-induced increase in late proestrus.

Detection of free peritoneal fluid by transvaginal sonography

The recognition of peritoneal fluid is of considerable clinical importance; however, the sensitivity of modern techniques for the detection of this finding has not been determined. The purpose of this study was to assess the utility of transvaginal sonography for the detection of free peritoneal fluid. Nineteen infertile women scheduled to undergo diagnostic laparoscopy were scanned with a 5-MHz transvaginal probe just before the surgical procedure. Peritoneal fluid was then aspirated laparoscopically, and the volume and location was compared to the sonographic findings. The volume of fluid obtained at laparoscopy ranged from 0 mL to 45 mL (median 8 mL). All patients with fluid volumes > or = 0.8 mL had free fluid identified sonographically. The location of fluid observed sonographically corresponded to that noted at laparoscopy in all cases. Free peritoneal fluid was visualized in 8 (73%) of 11 patients with regular menstrual cycles who were in the follicular phase at the time of the study. We conclude that transvaginal sonography is a sensitive and reliable method for the detection of free peritoneal fluid in anatomically normal women. This finding should not necessarily be considered abnormal, at least in women of reproductive age, nor should it be considered diagnostic of oocyte release.

The potential relevance of cytokines to ovarian physiology

Elucidating the secrets of intraovarian intercellular communication constitutes a central area of investigation. While most attention has been directed thus far at the somatic cellular components of the ovary, the potential role(s) and relative importance of the resident ovarian white blood cell have received relatively limited attention. Efforts are currently under way to reconcile traditional ovarian physiology with observations relevant to intraovarian components of the white blood cell series. In this connection, it is important to note that unlike some gonadal compartments, the ovary does not constitute an immunologically privileged site. Thus, resident ovarian representatives of the white blood cell series can be observed at various stages of the ovarian life cycle. Current concepts suggest that regulatory cellular networks formerly viewed in immune terms now fall within the broad domain of endocrinology. Viewed in this light, resident ovarian representatives of the white blood cell series may constitute potential in situ modulators of ovarian function acting in all likelihood through the local secretion of regulatory cytokines. As the flow of information is probably multi directional, the very same cells are probably targeted for steroidal and peptidergic input in keeping with the existence of multiple autocrine and paracrine loops.

Secretion of platelet-activating factor by periovulatory ovine follicles

Secretion of platelet-activating factor (PAF) in vitro by ovine follicles and ovarian interstitium obtained at various times before, during and after the endogenous preovulatory surge of luteinizing hormone (LH) and ovulation was quantified by radioimmunoassay. Release of PAF by the preovulatory follicle increased within 2 h after initiation of the surge of LH. Capacity for secretion of PAF was greatest at the time of ovulation, then declined thereafter. Production of PAF by ovarian interstitium throughout the periovulatory period was relatively low and did not change with time. It appears that PAF could act as an intrafollicular mediator in the mechanisms of ovulation and(or) luteinization.

Localization and hormonal regulation of ovarian production of histamine in the sheep

Concentrations of histamine were measured within the follicular wall, follicular fluid and ovarian interstitium throughout the periovulatory period in sheep. Histamine within follicular tissue declined after the onset of the preovulatory surge of luteinizing hormone (LH) and remained low until after ovulation, when levels then increased markedly. Alterations in histamine within the follicular wall were not reflected by corresponding changes within follicular fluid or ovarian interstitium. Release of histamine from tissue during short-term incubation was greatest for follicles obtained after ovulation, which was not influenced by presence of LH in the incubation medium. Luteinizing hormone caused depletion of stores of histamine from the wall of follicles collected before the preovulatory surge of LH. Histamine could act as a paracrine mediator in the follicular mechanisms of ovulation and(or) luteinization.