Prevalence and risk factors related to anovular phenotypes in dairy cows.

The objective of the current study was to evaluate the relationship of body condition score (BCS) at 35 d in milk (DIM), milk production, diseases, and duration of the dry period with prevalence of anovulation at 49 DIM and then, specifically, with the prevalence of each anovular phenotype. We hypothesized that anovular follicular phenotypes, classified based on maximal size of the anovular follicle, have different etiologies. A total of 942 lactating Holstein cows (357 primiparous and 585 multiparous) from 1 herd had ovaries evaluated by ultrasonography at 35 ± 3 and 49 ± 3 DIM to detect the absence of a corpus luteum (CL), and to measure the diameter of the largest follicle. Cows were classified as cyclic at 49 DIM if a CL was observed in at least 1 of the 2 examinations, or anovular if no CL was observed at either examination. Cows considered anovular were divided into 3 groups based on the largest diameter of the largest follicle as follows: ranging from 8 to 13 mm, 14 to 17 mm, or ≥18 mm. Cows were evaluated for the following diseases: retained placenta, metritis, hyperketonemia, mastitis, lameness, respiratory problem, and digestive problem. At 35 DIM, BCS was determined, and milk yield for individual cows was recorded. A total of 28.5% (268/942) of cows were classified as anovular. Anovular cows had longer dry periods (90 vs. 71 d) and smaller BCS than cyclic cows (2.83 vs. 2.99). Cows with a single disease or multiple diseases had 2 and 3-fold increase in odds of being anovular, respectively. Anovular cows had follicles that ranged from 4 to 50 mm. The prevalence of anovular phenotype, among anovular cows, that had the diameter of the largest follicle ranging from 8 to 13 mm, 14 to 17 mm, and ≥18 mm was 29.9 (79/264), 37.5 (99/264), and 32.6% (86/264), respectively. Anovular cows with follicles of 8 to 13 mm had longer dry periods than those with follicles ≥18 mm (104 vs. 74 d), whereas anovular cows with medium size follicles had intermediate days dry (99 d). Cows with small and medium anovular follicles had smaller BCS and greater prevalence of multiple diseases than cyclic cows. For almost all risk factors, the cows with large anovular follicles (≥18 mm) were similar to cyclic cows and different from cows with smaller anovular follicles (8-13 mm). Thus, longer dry periods, less BCS at 35 DIM, and diseases were risk factors for anovulation. Moreover, the risk factors for the 3 distinct anovular follicle phenotypes differed.

Recurrent hemoperitoneum secondary to haemorrhage from the corpus luteum unmasks factor V deficiency.

Factor V deficiency is a rare autosomal recessive coagulation disorder. We report a case with inherited factor V deficiency presenting as life-threatening recurrent hemoperitoneum, following bleeding from ruptured corpus haemorrhagicum. Prolonged prothrombin and activated partial thromboplastin times, normal thrombin time and a normal platelet count pointed towards a disorder of coagulation. Mixing studies with factor V deficient plasma and coagulation factor assay revealed markedly reduced plasma factor V clotting activity. The management included blood, plasma and tranexamic acid. Family screening revealed low factor V levels in her parents. Although her brother had significant Factor V deficiency and epistaxis, he did not need hospitalization or replacement, indicating the varied manifestation of this bleeding defect in this family.

Loss of function of endothelin-2 leads to reduced ovulation and CL formation.

Endothelin-2 (EDN2), a potent vasoconstrictive peptide, is transiently produced by periovulatory follicles at the time of ovulation when corpus luteum (CL) formation begins. EDN2 induces contraction of ovarian smooth muscles ex vivo via an endothelin receptor A-mediated pathway. In this study, we aimed to determine if EDN2 is required for normal ovulation and subsequent CL formation in?vivo. In the ovaries of a mouse model that globally lacks the Edn2 gene (Edn2 knockout mouse; Edn2KO), histology showed that post-pubertal Edn2KO mice possess follicles of all developmental stages, but no corpora lutea. When exogenous gonadotropins were injected to induce super-ovulation, Edn2KO mice exhibited significantly impaired ovulation and CL formation compared to control littermates. Edn2KO ovaries that did ovulate in response to gonadotropins did not contain histologically and functionally identifiable CL. Intra-ovarian injection of EDN2 peptide results suggest partial induction of ovulation in Edn2KO mice. Endothelin receptor antagonism in wild type mice similarly disrupted ovulation, CL formation, and progesterone secretion. Overall, this study suggests that EDN2 is necessary for normal ovulation and CL formation.

Contrast imaging ultrasound detects abnormalities in the marmoset ovary.

The development of a functional vascular tree within the primate ovary is critical for reproductive health. To determine the efficacy of contrast agents to image the microvascular environment within the primate ovary, contrast ultrasonography was performed in six reproductive-aged female common marmosets (Callithrix jacchus) during the late luteal phase of the cycle, following injection of Sonovue™. Regions of interest (ROIs), representing the corpus luteum (CL) and noncorpus luteum ovarian tissue (NCLOT), were selected during gray-scale B-mode ultrasound imaging. The magnitude of backscatter intensity of CL and NCLOT ROIs were calculated in XnView, post hoc: subsequent gamma-variate modeling was implemented in Matlab to determine perfusion parameters. Histological analysis of these ovaries revealed a total of 11 CL, nine of which were identified during contrast ultrasonography. The median enhancement ratio was significantly increased in the CL (5.54AU; 95% CI -2.21-68.71) compared to the NCLOT (2.82AU; 95% CI 2.73-15.06; P < 0.05). There was no difference in time parameters between the CL and NCLOT. An additional avascular ROI was identified in the ovary of Animal 5, both histologically and by ultrasonography. This cystic ROI displayed a markedly lower enhancement ratio (0.79AU) and higher time parameters than mean CL and NCLOT, including time to peak and time to wash out. These data demonstrate, for the first time, the ability of commercially available contrast agents, to differentiate structures within the nonhuman primate ovary. Contrast-enhanced ultrasonography has a promising future in reproductive medicine.

Generation of ERα-floxed and knockout mice using the Cre/LoxP system.

Estrogen receptor alpha (ERα) is a nuclear receptor that regulates a range of physiological processes in response to estrogens. In order to study its biological role, we generated a floxed ERα mouse line that can be used to knock out ERα in selected tissues by using the Cre/LoxP system. In this study, we established a new ERα knockout mouse line by crossing the floxed ERα mice with Cre deleter mice. Here we show that genetic disruption of the ERα gene in all tissues results in sterility in both male and female mice. Histological examination of uterus and ovaries revealed a dramatically atrophic uterus and hemorrhagic cysts in the ovary. These results suggest that infertility in female mice is the result of functional defects of the reproductive tract. Moreover, female knockout mice are hyperglycemic, develop obesity and at the age of 4 months the body weight of these mice was more than 20% higher compared to wild type littermates and this difference increased over time. Our results demonstrate that ERα is necessary for reproductive tract development and has important functions as a regulator of metabolism in females.

Deletion of Otx2 in GnRH neurons results in a mouse model of hypogonadotropic hypogonadism.

GnRH is the central regulator of reproductive function responding to central nervous system cues to control gonadotropin synthesis and secretion. GnRH neurons originate in the olfactory placode and migrate to the forebrain, in which they are found in a scattered distribution. Congenital idiopathic hypogonadotropic hypogonadism (CIHH) has been associated with mutations or deletions in a number of genes that participate in the development of GnRH neurons and expression of GnRH. Despite the critical role of GnRH in mammalian reproduction, a comprehensive understanding of the developmental factors that are responsible for regulating the establishment of mature GnRH neurons and the expression of GnRH is lacking. orthodenticle homeobox 2 (OTX2), a homeodomain protein required for the formation of the forebrain, has been shown to be expressed in GnRH neurons, up-regulated during GnRH neuronal development, and responsible for increased GnRH promoter activity in GnRH neuronal cell lines. Interestingly, mutations in Otx2 have been associated with human hypogonadotropic hypogonadism, but the mechanism by which Otx2 mutations cause CIHH is unknown. Here we show that deletion of Otx2 in GnRH neurons results in a significant decrease in GnRH neurons in the hypothalamus, a delay in pubertal onset, abnormal estrous cyclicity, and infertility. Taken together, these data provide in vivo evidence that Otx2 is critical for GnRH expression and reproductive competence.

Effects of neonatally administered diethylstilbestrol on induction of mammary carcinomas induced by 7, 12-dimethylbenz(a)anthracene in female rats.

Various doses of diethylstilbestrol (DES) were administered to rats once at birth. Thereafter, at 50 days after birth, the rats in all groups were given 10 mg 7, 12-dimethylbenz[a]anthracene (DMBA) and undergone necropsy at 300 days after birth. The incidence of mammary carcinomas (MCs) were 50, 54, 91, 39, 19% at 175 days after birth, and 77, 87, 100, 85, 75% at necropsy in the 0, 0.1, 1, 10, 100 microg groups, respectively. The incidence of rats without corpus luteum were 0, 0, 0, 30, 100% at 50 days after birth, and 0, 40, 53, 93, 100% at necropsy in the 0, 0.1, 1, 10, 100 microg groups, respectively. Observation of the whole mount specimens showed a higher number of terminal end buds (TEBs) in the 1 microg group and a lower number in the 100 microg group compared with the control at 50 days after birth. It suggested that the administration of a relatively low dose (1 microg) of DES during neonatal period may increase TEBs, thus resulting in a stimulatory effect on the initiation of MCs.

Cell-specific knockout of steroidogenic factor 1 reveals its essential roles in gonadal function.

Knockout (KO) mice lacking the orphan nuclear receptor steroidogenic factor 1 (SF-1, officially designated Nr5a1) have a compound endocrine phenotype that includes adrenal and gonadal agenesis, impaired expression of pituitary gonadotropins, and structural abnormalities of the ventromedial hypothalamic nucleus. To inactivate a conditional SF-1 allele in the gonads, we targeted the expression of Cre recombinase with a knock-in allele of the anti-Müllerian hormone type 2 receptor locus. In testes, Cre was expressed in Leydig cells. The testes of adult gonad-specific SF-1 KO mice remained at the level of the bladder and were markedly hypoplastic, due at least partly to impaired spermatogenesis. Histological abnormalities of the testes were seen from early developmental stages and were associated with markedly decreased Leydig cell expression of two essential components of testosterone biosynthesis, Cyp11a and the steroidogenic acute regulatory protein. In females, the anti-Müllerian hormone type 2 receptor-Cre allele directed Cre expression to granulosa cells. Although wild-type and SF-1 KO ovaries were indistinguishable during embryogenesis and at birth, adult females were sterile and their ovaries lacked corpora lutea and contained hemorrhagic cysts resembling those in estrogen receptor alpha and aromatase KO mice. Collectively, these studies establish definitively that SF-1 expression in the gonads is essential for normal reproductive development and function.

Aberrant intracellular cholesterol transport disrupts pituitary and ovarian function.

Cholesterol is imported and processed to provide substrate for ovarian steroidogenesis. The Niemann Pick type C-1 gene codes for a glycoprotein that processes low-density lipoproteinimported cholesterol. Mutation of this gene causes marked impairment of export of low-density lipoprotein-derived cholesterol from endosomes, and consequent lysosomal accumulation of the sterol. The BALB/c npc(nih-/-) mouse line, bearing spontaneous mutation of the NPC-1 gene, provides a model for investigation of aberrant endosomal cholesterol transfer in the ovary. Female homozygote mutant mice are infertile, with underdeveloped ovarian follicles, reduced steroidogenesis, no ovulation, and no corpora lutea. Mutant ovaries transplanted under wild-type kidney capsules display both ovulation and formation of corpora lutea. Gonadotropin treatment induces ovulation and restores expression of steroidogenic proteins. Pituitary glands of mutants are hypoplastic, and prolactin expression is dramatically reduced compared with wild-type mice. Both long and short splice variants of the dopamine-D2 receptors are overexpressed in the pituitary of BALB/c npc(nih-/-) mice. Chronic treatment of mutant mice with 17beta-estradiol restores pituitary volume, prolactin expression, and folliculogenetic capability. We conclude that inactivating mutation of Niemann Pick C-1 perturbs the hypothalamic-pituitary-ovarian feedback loop. Reduced estrogens attenuate prolactin expression and alter gonadotropin secretion patterns and interfere with normal ovarian follicular development and ovulation.

Mutant mouse models and their contribution to our knowledge of corpus luteum development, function and regression.

The corpus luteum is a unique organ, which is transitory in nature. The development, maintenance and regression of the corpus luteum are regulated by endocrine, paracrine and autocrine signaling events. Defining the specific mediators of luteal development, maintenance and regression has been difficult and often perplexing due to the complexity that stems from the variety of cell types that make up the luteal tissue. Moreover, some regulators may serve dual functions as a luteotropic and luteolytic agent depending on the temporal and spatial environment in which they are expressed. As a result, some confusion is present in the interpretation of in vitro and in vivo studies. More recently investigators have utilized mutant mouse models to define the functional significance of specific gene products. The goal of this mini-review is to identify and discuss mutant mouse models that have luteal anomalies, which may provide some clues as to the significance of specific regulators of corpus luteum function.

Formation of a secondary corpus luteum after ultrasound-guided follicular aspiration in cows.

This paper reports the observed formation of a secondary corpus luteum (CL) in the presence of the cyclic corpus luteum, on the ovaries of a cow after ultrasound-guided follicular aspiration for oocyte recovery. The secondary structure, although smaller and lighter (4.97 g vs. 6.02 g) than the natural one, had the typical macroscopic appearance of a corpus luteum. Histological examination of the structure using electron microscopy revealed typical structural features of a natural CL. Mean tissue progesterone concentration was significantly lower in the secondary CL (31.15 +/- 3.11 compared with 58.29 +/- 6.32 micrograms/g tissue of the cyclic CL) and oestradiol-17 beta significantly higher than in the natural CL (108 +/- 11.6 compared with 74.2 +/- 7.81 pg/g tissue). P450scc and P450(17 alpha) mRNA was detected in both structures while P450arom and full-length mRNA FSH receptor were detected only in the secondary structure.

Incidence of gross reproductive abnormalities in small east African zebu cattle.

Reproductive organs from mature Small East African zebu (SEAZ) heifers and cows slaughtered at the Morogoro abattoir were collected twice a month and evaluated over a period of 12 months. Out of the 402 animals from which reproductive organs were taken, 54% were pregnant, 24% were actively cycling and 22% were non-cycling. Various gross abnormalities were observed in the reproductive organs of about 16% of the cattle, and the major reproductive abnormality in both total and the non-cycling animals was various degrees of fibrous adhesion between the ovary and the infundibulum and mesosalpinx. It is concluded that, contrary to common belief, a majority of the female SEAZ cattle that are slaughtered are fertile.

A propósito de un caso de embarazo ectópico de ovario y cuerpo lúteo roto contralateral con hemiperitoneo masivo / Pregnancy ectopic, ovary and ruptured contralateral corpus luteum and massive hemoperitoneum: one case

El presente caso reporta la asociación de un embarazo ectópico de ovario derecho que cumple los criterios de Spiegelberg para su diagnóstico relacionado a la presencia de la ruptura del cuerpo lúteo contralateral con hemoperitoneo masivo, motivando una laparotomía de emergencia. El reporte anatomo-patológico diagnosticó gestación en etapa inicial en ovario derecho y ruptura de cuerpo lúteo izquierdo

Reproductive tract abnormalities in female mice treated neonatally with tamoxifen.

Immature female mice of the NMRI strain were treated with 20 micrograms/day of tamoxifen or vehicle for the first 3 days after birth. At 90 days of age, vaginas, uteri, and ovaries were examined histologically. A benign epithelial change, vaginal adenosis characterized by abnormal growth of columnar epithelium with glandular structures, was found in all of the tamoxifen-treated mice. Anatomic anomalies such as hypospadias, cervical hypoplasia, uterine hypoplasia, and absence of corpora lutea also were commonly observed. Such abnormalities were not found in the control mice.

[Histological studies and pathogenesis of polycystic ovaries]. / Histologische Untersuchungen und Pathogenese polyzystischer Ovarien

58 ovarian wedge resections of 34 patients with the clinical diagnosis "Stein-Leventhal-syndrome" were histologically examined in comparison to 23 ovaries or parts of ovaries of 16 patients with regular ovarian cyclus. There was found no important difference in these two groups apart from a hyperplasia of the tunica albuginea and the absence of corpora lutea. According to our investigations, and regarding well known facts, it must be concluded that the polycystis ovaries are nothing else than the result of a disturbance of cyclic gonadotropin secretion, and thus an expression of anovulation with sufficient ovaries.