COVID-19 impact on reproduction and fertility.

The COVID-19 pandemic is an unexpected worldwide situation, and all countries have implemented their own policies to curb the spread of the virus. The pathophysiology of COVID-19 has opened numerous hypotheses of functional alterations in different physiological aspects. The direct impact of SARS-CoV-2 on the urogenital organs of males and females is still to be assessed. Nevertheless, based on biological similarities between SARS-CoV and SARS-CoV-2, several hypotheses have been proposed. In this study, we will discuss the possible mechanism of action, and potential effects on the male/female reproductive system and fertility.

Hypogonadism in Pediatric Health: Adult Medicine Concepts Fail.

The classical definition of hypogonadism, used in adult medicine, as gonadal failure resulting in deficient steroid and gamete production, and its classification into hypergonadotropic and hypogonadotropic refer to primary gonadal and hypothalamic-pituitary disorders respectively and may lead to under- or misdiagnosis in pediatrics. Indeed, in children with primary gonadal failure, gonadotropin levels may be within the reference range for age. Conversely, since gonadotropins and steroids are normally low during childhood, it may prove impossible to show the existence of a hypogonadotropic state before pubertal age. Anti-Müllerian hormone (AMH) and inhibin B arise as more adequate biomarkers to assess gonadal function and increase the possibility of making an earlier diagnosis of hypogonadism in children, which may positively impact on timely management.

Kisspeptin/GPR54 System: What Do We Know About Its Role in Human Reproduction?

Kisspeptin is involved in the control of human reproduction bridging the gap between the sex steroid levels and feedback mechanisms that control the gonadotropin releasing hormone (GnRH) secretion; however, studies considering this peptide and infertility are limited. We conducted a review and critical assessment of available evidence considering kisspeptin structure, physiology, function in puberty and reproduction, its role in assisted reproduction treatments, kisspeptin dosage and the impact on KISS1 and GPR54 genes. Literature searches were conducted in PubMed using keywords related to: (i) kisspeptin or receptors, kisspeptin-1 (ii) reproduction or infertility or fertility (iii) gene and (iv) dosage or measurement or quantification or serum level, in human. Kisspeptin is a product of KISS1 gene that binds to a G-protein-coupled receptor (GPR54/KISS1R) stimulating the release of GnRH by hypothalamic neurons, leading to secretion of pituitary gonadotropins (LH and FSH) and sexual steroids, which in turn will act in the gonads to produce the gametes. Kisspeptin is being recognized as a crucial regulator of the onset of puberty, the regulation of sex hormone mediated secretion of gonadotropins, and the control of fertility. Inactivating and activating mutations in both KISS1 or GPR54 genes were associated with hypogonadotropic hypogonadism and precocious puberty. Despite this, studies considering kisspeptin and infertility are scarce. The understanding of the role of kisspeptin may lead to its use as a biomarker in infertility treatments and use in controlled ovarian hyperstimulation.

When hormone defects cannot explain it: malformative disorders of sex development.

The birth of a baby with malformations of the genitalia urges medical action. Even in cases where the condition is not life-threatening, the identification of the external genitalia as male or female is emotionally essential for the family, and genital malformations represent one of the most stressful situations around a newborn. The female or male configuration of the genitalia normally evolves during fetal life according to the genetic, gonadal, and hormonal sex. Disorders of sex development occur when male hormone (androgens and anti-Müllerian hormone) secretion or action is insufficient in the 46,XY fetus or when there is an androgen excess in the 46,XX fetus. However, sex hormone defects during fetal development cannot explain all congenital malformations of the reproductive tract. This review is focused on those congenital conditions in which gonadal function and sex hormone target organ sensitivity are normal and, therefore, not responsible for the genital malformation. Furthermore, because the reproductive and urinary systems share many common pathways in embryo-fetal development, conditions associating urogenital malformations are discussed.

Extrapituitary growth hormone synthesis in humans.

The gene for pituitary growth hormone (GH-N) in man belongs to a multigene locus located at chromosome 17q24.2, which also harbors four additional genes: one for a placental variant of GH-N (named GH-V) and three of chorionic somatommamotropin (CSH) type. Their tandem arrangement from 5' to 3' is: GH-N, CSH-L, CSH-1, GH-V and CSH-2. GH-N is mainly expressed in the pituitary from birth throughout life, while the remaining genes are expressed in the placenta of pregnant women. Pituitary somatotrophs secrete GH into the bloodstream to act at receptor sites in most tissues. GH participates in the regulation of several complex physiological processes, including growth and metabolism. Recently, the presence of GH has been described in several extrapituitary sites, such as neural, ocular, reproductive, immune, cardiovascular, muscular, dermal and skeletal tissues. It has been proposed that GH has an autocrine action in these tissues. While the body of evidence for its presence is constantly growing, research of its possible function and implications lag behind. In this review we highlight the evidence of extrapituitary synthesis of GH in humans.

The effect of fetal androgen metabolism-related gene variants on external genitalia virilization in congenital adrenal hyperplasia.

The 21-hydroxylase deficiency (21OHD) is caused by CYP21A2 mutations resulting in severe or moderate enzymatic impairments. 21OHD females carrying similar genotypes present different degrees of external genitalia virilization, suggesting the influence of other genetic factors. Single nucleotide variants (SNVs) in the CYP3A7 gene and in its transcription factors, related to fetal 19-carbon steroid metabolism, could modulate the genital phenotype. To evaluate the influence of the 21OHD genotypes and the CYP3A7, PXR and CAR SNVs on the genital phenotype in 21OHD females. Prader scores were evaluated in 183 patients. The CYP3A7, PXR and CAR SNVs were screened and the 21OHD genotypes were classified according to their severity: severe and moderate groups. Patients with severe genotype showed higher degree of genital virilization (Prader median III, IQR III-IV) than those with moderate genotype (III, IQR II-III) (p < 0.001). However, a great overlap was observed between genotype groups. Among all the SNVs tested, only the CAR rs2307424 variant correlated with Prader scores (r(2) = 0.253; p = 0.023). The CYP21A2 genotypes influence the severity of genital virilization in 21OHD females. We also suggest that the CAR variant, which results in a poor metabolizer phenotype, could account for a higher degree of external genitalia virilization.

Effects of tributyltin exposure in hermit crabs: Clibanarius vittatus as a model.

Tributyltin (TBT) contamination affects the reproductive system of many species of invertebrates worldwide. The present study was designed to evaluate the effects of exposure to TBT pollution on the reproduction of the hermit crab Clibanarius vittatus. An orthogonal experiment was designed with two treatments: contamination (with or without TBT in the food) and crab sex (males and females). The animals were reared in the laboratory for nine months, and macroscopic and histological analyses of reproductive organs were carried out after the end of the experiment. Tributyltin was recorded in exposed crabs, but no morphological alterations were detected in the gonads of males, regardless of whether they were exposed to TBT. In contrast, females exposed to TBT displayed disorganization and atrophy of their ovaries, thus directly affecting reproduction in this hermit crab species. This effect observed in female hermit crabs may harm populations located in harbor regions, where TBT concentration is high, even after the worldwide TBT ban.

Hox gene expression in the embryonic genital system of the sea turtle Lepidochelys olivacea (Eschscholt, 1829), a species with temperature-dependent sex determination.

Hox genes are conserved transcription factors which regulate embryonic morphogenesis and differentiation. For the first time, we examined the quantitative and spatial expression of two Hox 5' genes, HoxD11 and HoxA13, in the developing genital system of the olive ridley Lepidochelys olivacea, a species with temperature-dependent sex determination. Quantitative and spatial expression patterns of both genes suggest a role in the female pathway rather than the male pathway. For instance, both genes, especially HoxA13, were expressed in the undifferentiated gonad during the thermosensitive period at a female promoting temperature, and downregulated in the differentiated gonad. By contrast, expression of both genes was low in gonads incubated at a male promoting temperature and did not change significantly in the differentiated gonad. Furthermore, we found high expression levels of HoxA13 in the paramesonephric duct at the male promoting temperature but not at the female promoting temperature, suggesting a role for this Hox gene in the partial regression of the Müllerian duct in males.

Uso de subprodutos do algodão na nutrição de ruminantes / Use of cotton byproducts in ruminant nutrition

O caroço, o farelo e a torta de algodão destacam-se como fonte alternativa de proteina e energia, que pode diminuir o custo da dieta dos animais. Estes produtos apresentam elevada quantidade de ácidos graxos, o que pode propiciar maior deposição de gordura na carcaça e maior ganho em peso, além de uma carne de melhor qualidade. Uma das grandes limitações para o uso desses produtos na nutrição animal é a presença de quantidades elevadas de gossipol (Gp). Esta substância é tóxica para os animais, sendo bastante conhecidos os seus efeitos deletérios no sistema reprodutivo de machos, principalmente em animais jovens. Esta caracteristica tem criado alguma resistência ao uso desses produtos na nutrição de ruminantes. Entretanto, apesar do potencial tóxico do Gp e de fatores de risco associados com a diminuição da fertilidade, os subprodutos de algodão oferecem uma alternativa que pode ser segura para a alimentação de ruminantes quando o teor desta substância no alimento é conhecido e utilizado em níveis recomendados. Dessa forma, realizou-se a presente revisão objetivando esclarecer dúvidas quanto ao uso dos subprodutos do algodão na alimentação de ruminantes, evidenciando resultados de efeitos no sistema reprodutivo e de desempenho dos animais.

The whole cotton seed, the bran and pie stands out as an alternative source of protein and energy, which can decrease the cost of the animal diet. These products feature high amounts of fatty acids, which may provide greater deposition of carcass fat and increased weight gain, and better meat quality. A major limitation for using these products in animal nutrition is the presence of high amounts of gossypol. This substance is toxic to animals and their harmful effects are well known on the reproductive system of males, especially in young animals. This feature has created some resistance in using these products in ruminant nutrition. Despite the potential toxic effects of Gp and risk factors associated with declining fertility, the byproducts of cotton offer an alternative that can be safely fed to ruminants if the level of Gp in the food is known and used at recommended levels. Thus, we carried out this review aiming to clarify the doubts regarding the use of cotton byproducts in ruminant feeding, presenting results of effects on the reproductive system and in the performance of animals.

Histological and histochemical characterization of the secretory cells of Choeradoplana iheringi Graff, 1899 (Platyhelminthes: Tricladida: Terricola).

The present study aims at providing a detailed description of the histology, as well as the first histochemical characterization, of the secretory cells of the epidermis, pharynx, and copulatory organs of Choeradoplana iheringi, in order to give further support to studies on the physiology of these organs. The secretory cells are distinguished on the basis of secretion morphology and its staining properties, using trichrome methods and histochemical reactions. Four cell types open through the epidermis of Ch. iheringi, three of them secreting basic protein and a fourth containing glycosaminoglycan mucins. The epidermal lining cells store glycogen. In the pharynx, four secretory cell types were distinguished. Two types produce glycoprotein, a third type secretes basic protein, and another one produces glycosaminoglycan mucins. In the male copulatory organs, the prostatic vesicle receives four secretory cell types containing basic protein, except for one type which produces glycoprotein. The two secretory cell types opening into the male atrium secrete, respectively, glycoprotein, and glycosaminoglycan mucins. In the female copulatory organs, the female atrium and its proximal diverticulum, the vagina, receive two types of secretory cells producing, respectively, basic protein and glycosaminoglycan mucins. Another secretory cell type constitutes the so-called shell glands which open into the common glandular duct, secreting basic protein. The lining cells of the male and female atria produce a mucous secretion containing glycosaminoglycans. In addition, the lining epithelium of the female atrium presents an apical secretion of a proteic nature. The occurrence of a kind of spermatophore is reported for the first time for a species of Choeradoplana. This structure is located in the male or female atria in different specimens, and characterized by erythrophil, xanthophil, and/or mixed secretions associated with sperm.

Cell aggregation precedes the onset of Sox9-expressing preSertoli cells in the genital ridge of mouse.

SOX9 is expressed at the onset of the genital ridge formation in both sexes. It is assumed that SRY, the testis determining gene, turns SOX9 on in male embryos because it is turned off in female embryos. Spatial expression of SRY follows a cranio-caudal pattern. Here, we asked if SOX9 is expressed in the same cell lineage and with a similar pattern as SRY. A correlative study between the structural changes in the genital ridge and the immunocytochemical localization of SOX9-positive cells was undertaken. We used a transgenic strain expressing the green fluorescent protein (GFP) that considerably enhanced the cell context where the first SOX9-positive cells appear. Although SOX9-positive cells are located among loose mesenchymal cells by stages of 8-14 tail somites (ts) in both sexes, they are absent in the thickening coelomic epithelium of females. At 15 ts the first SOX9-positive cells appear within the core of the condensed cells only in male genital ridges. At 17 ts, a gradient of SOX9-positive cells in males is apparent, closely following the cranio-caudal pattern of cell aggregation seen in genital ridges of both sexes. Hence, our results suggest that SOX9 is expressed only in loose mesenchymal cells in both sexes and that expression of SOX9 in males requires the prior aggregation of cells in the genital ridges. The correspondence of SOX9 and SRY pattern of expression supports that both genes are expressed in the preSertoli cell lineage in the core of the genital ridges.

Suckling and genital stroking induces Fos expression in hypothalamic oxytocinergic neurons of rabbit pups.

Maternal behaviour in the rabbit is unusual among mammals because the doe visits her litter to nurse once every 24 h. In the present study we examined the consequences of milk intake on oxytocinergic (OT) and vasopressinergic (AVP) neurons of the supraoptic (SON) and paraventricular (PVN) nuclei of 7-day-old pups before suckling, after suckling and following anogenital stroking in un-nursed pups. To determine neuronal activation we assessed the expression of the Fos protein combined with antibodies against OT and AVP at two levels in the SON (supraoptic rostral, SOr, and supraoptic retrochiasmatic, SOrch), and three levels in the PVN (anterior, PVab; medial PVm and caudal, PVc). Daily nursing bouts lasted only 228+/-6 s throughout the observed 7 days, and pups ingested up to 34.95+/-9.0% of their body weight in milk on day 7, the day of perfusion. Suckling induced a significant increase in the number of double-labeled Fos/OT cells in both subdivisions of the SON (P<0.01) and in PVab and PVm (P<0.01). The effect in the SON was related to suckling, as it was not seen in stroked, un-nursed pups, which showed Fos increases only in PVab and PVm. All regions in the SON and PVN showed significant increases in the number of Fos/AVP neurons after suckling or stroking but, contrary to OT, the number of double-labeled Fos/AVP cells was very low. In conclusion, our results show that the oxytocinergic system of the SON and PVN is differentially activated by suckling of milk and anogenital stroking, and that the vagal-hypothalamic axis is mature in 7-day-old rabbits.

Atividade endócrina relacionada aos órgäos sexuais na pós-menopausa / Endocrine activity related to sexual organs during postmenopause

A atividade endócrina relacionada com os órgäos sexuais foi avaliada em mulheres menopausadas e pós-menopausadas, antes e depois da ressecçäo cirúrgica bilateral dos ovários. Comparando os valores urinários das gonadotrofinas dos 17-cetoesteróides e estrogênios, comprova-se uma persistente atividade endócrina nos ovários senis