The reduction of the m6A methyltransferase METTL3 in granulosa cells is related to the follicular cysts in pigs.

Follicular cysts are a common reproductive disorder in domestic animals that cause considerable economic losses to the farming industry. Effective prevention and treatment methods are lacking because neither the pathogenesis nor formation mechanisms of follicular cysts are well-understood. In this study, we first investigated the granulosa cells (GCs) of cystic follicles isolated from pigs. We observed a significant reduction in the expression of methyltransferase-like 3 (METTL3). Subsequent experiments revealed that METTL3 downregulation in GCs caused a decrease in m6A modification of pri-miR-21. This reduction further inhibited DGCR8 recognition and binding to pri-miR-21, dampening the synthesis of mature miR-21-5p. Additionally, the decrease in miR-21-5p promotes IL-1ß expression in GCs. Elevated IL-1ß activates the NFκB pathway, in turn upregulating apoptotic genes TNFa and BAX/BCL2. The subsequent apoptosis of GCs and inhibition of autophagy causes downregulation of CYP19A1 expression. These processes lower oestrogen secretion and contribute to follicular cyst formation. In conclusion, our findings provide a foundation for understanding and further exploring the mechanisms of follicular-cyst development in farm animals. This work has important implications for treating ovarian disorders in livestock and could potentially be extended to humans.

Altered vitamin D metabolic system in follicular cysts of sows.

This study aimed to examine 25OHD3 concentration in the fluid of follicular and follicular lutein cysts of sows in comparison with preovulatory follicles as well as immunolocalize vitamin D metabolic enzymes (CYP27B1 and CYP24A1) and determine their protein abundances in the cyst wall. We have shown for the first time that 25OHD3 level in the fluid of both cyst types was significantly lower than in preovulatory follicles. Furthermore, we have demonstrated CYP27B1 and CYP24A1 protein immunolocalization and abundance in follicular and follicular lutein cysts. The abundance of protein for both metabolic enzymes was decreased in ovarian cysts when compared to preovulatory follicles. We propose that altered VD metabolism in ovarian cyst might associate with their formation in sows.

Lats1 Deletion Causes Increased Germ Cell Apoptosis and Follicular Cysts in Mouse Ovaries.

The Hippo signaling pathway is essential for regulating proliferation and apoptosis in mammalian cells. The LATS1 kinase is a core member of the Hippo signaling pathway that phosphorylates and inactivates the transcriptional co-activators YAP1 and WWTR1. Deletion of Lats1 results in low neonate survival and ovarian stromal tumors in surviving adults, but the effects of Lats1 on early follicular development are not understood. Here, the expression of Hippo pathway components including Wwtr1, Stk4, Stk3, Lats2, and Yap1 transcripts were decreased by 50% in mouse ovaries between 2 and 8 days of age while expression was maintained from 8 days to 21 days and after priming with eCG. LATS1, LATS2, and MOB1B were localized to both germ and somatic cells of primordial to antral follicles. Interestingly, YAP1 was predominantly cytoplasmic, whereas WWTR1 was nuclear in oocytes and somatic cells. Deletion of Lats1 caused an increase in germ cell apoptosis from 1.7% in control ovaries to 3.6% in Lats1 mutant ovaries and a 58% and 32% decrease in primordial and activated follicle numbers in cultured mutant ovaries. Surprisingly, there was an increase in Bmp15 but not Gdf9, Figla, Nobox transcripts or the somatic-specific transcripts Amh and Wnt4 in cultured Lats1 mutant ovaries. Last, Lats1 mutant ovaries developed ovarian cysts at a higher frequency (43%) than heterozygous (24%) and control ovaries (8%). Results showed that the Hippo pathway is active in ovarian follicles and that LATS1 is required to maintain the pool of germ cells and primordial follicles.

Acid-base parameters and steroid concentrations in pre-ovulatory follicles and plasma of lactating dairy cows with spontaneous and synchronized oestrus or follicular cyst.

The study aimed to compare the acid-base balance and steroid concentrations between follicular fluids (FF) of pre-ovulatory follicles derived from a spontaneous oestrus (SO), synchronized or induced oestrus (IO) and follicular cysts (CYS) and between FF and blood in dairy cows. Forty-two dairy cows were included in this study. The animals were allocated to three groups: SO (n = 23); IO (n = 11) using GnRH at day 0 and day 9 and PGF2 α at day 7; and animals with CYS (n = 10). The follicular fluids (FF) were aspirated from the cyst/pre-ovulatory follicles (∅ ≥ 15 mm) after SO and after second GnRH dose in IO by transvaginal ultrasound-guided ovum pick-up technique. Blood samples (BL) were collected in heparinized vacutainer tubes. The oxygen tension (pO2) in FF of IO was higher (p < 0.05) than in SO and CYS groups. There were negative correlations (p < 0.001, r = -0.89) between FF and blood pO2. The carbon dioxide tension (pCO2) and lactate level in FF of CYS group were higher (p < 0.05) than in SO and IO groups. There were negative correlations (p < 0.01, r = -0.73) between blood and FF pO2. Oestradiol-17ß concentration in pre-ovulatory follicles and plasma of the SO group was higher (p < 0.001) than in IO and CYS groups. Progesterone concentration in pre-ovulatory follicles and plasma of the SO and IO groups was lower (p < 0.01) than in CYS group. Plasma androstenedione concentration in SO and IO groups was higher (p < 0.05) than in CYS group. In conclusion, acid-base parameters, E2 and P4 levels in the follicular fluid of both IO and CYS groups were deviated greatly from the physiological level (disturbances of intrafollicular/intracystic environment), which may affect the quality of both the oocyte and the granulosa cells.

[Ki-67 and matrix metalloproteinase-9 expression in the follicular cyst, keratocystic odontogenic tumor, and ameloblastoma].

An immunohistochemical study using antibodies against Ki-67 protein was conducted, which characterized the proliferative activity of cells and matrix metalloproteinase-9 (MMP-9) in follicular cyst, variants of keratocystic odontogenic tumor (with a preponderance of hyperkeratosis and parakeratosis), and ameloblastoma. The marked proliferative activity of a parabasal cell layer (28.0+/-8.4%) was found in the keratocystic odontogenic tumor with a preponderance of parakeratosis; the proliferative activity of the peripheral layer of ameloblastoma cells was equal to 7.0+/-5.6%. The maximal matrix metalloproteinase-9 expression in the keratocystic odontogenic tumor with a predominance of hyperkeratosis was 1.1 +/-0.9 conventional units (CU) and that in the ameloblastoma was 1.9+/-1.3 CU versus 0.4+/-0.5 CU in the follicular cyst, keratocystic odontogenic tumor with a preponderance of hyperkeratosis. The values of Ki-67 and MMP-9 expression allow one to distinguish benign odontogenic cysts and tumors (follicular cyst and keratocystic odontogenic tumor with a predominance of hyperkeratosis) and odontogenic tumors characterized by an aggressive clinical course (keratocystic odontogenic tumor with a preponderance of parakeratosis and ameloblastoma).

Abundance of Anti-Muellerian hormone in cat ovaries and correlation of its plasma concentration with animal age, weight and stage of the estrous cycle.

In female animals of different species, Anti-Müllerian hormone (AMH) is produced by follicular granulosa cells and has been associated with the ovarian follicle pool. Because concentration of AMH in plasma of ovary-intact female cats is apparently more variable than previously assumed, we have analysed AMH concentration in blood of cats (n = 93) presented for routine ovariectomy and assessed ovarian histology and AMH protein expression in the surgically removed ovaries. We hypothesised that AMH is synthesized only in preantral and small antral follicles and that plasma AMH concentration reflects the antral follicle count (AFC). Corpora lutea were detected in 35% of the female cats, whereas plasma progesterone concentration was ≥1 ng/mL in 57% of the cats. Follicular cysts were present in 15 cats (16%). Positive immunostaining for AMH protein was detected in close to all primordial and antral follicles, ovarian cysts, 70% of corpora lutea and 28% of atretic follicles. Concentration of AMH in plasma averaged 6.8 ± 0.5 ng/mL (range 1.3-21.7 ng/mL). The AFC increased with increasing AMH concentration with a moderate positive correlation between AFC and AMH (r = 0.286, p < 0.01). Plasma AMH concentration was not affected by season or cats' age, weight, stage of the estrous cycle and presence of follicular cysts. In conclusion, AMH protein is expressed in all endocrine structures of the cat ovary. While AMH is a marker for the presence of ovarian tissue, its usefulness to assess ovarian function in individual female cats is of limited value.

A review on inflammation and angiogenesis as key mechanisms involved in the pathogenesis of bovine cystic ovarian disease.

Cystic ovarian disease (COD) is an important cause of reproductive failure in dairy cattle. The main aim of this review is to discuss some aspects related to inflammation and angiogenesis that seem to be involved in the development of follicular cysts in domestic animals, with special emphasis on the bovine species, in an attempt to elucidate the relationship between these two processes in the early stages of persistence and in the development of bovine COD. We describe the changes in the expression of cytokines and angiogenic factors that seem to generate disturbances in the intraovarian component underlying the aberrant persistence of follicular cysts. Results show that pro-inflammatory and anti-inflammatory cytokines behave as regulators of angiogenesis through direct and indirect effects, like overexpression of pro-angiogenic factors, particularly in bovine ovarian cells from follicular cysts and persistent follicles. We conclude that, in dairy cattle, an imbalance in the expression of cytokines and pro-angiogenic growth factors related to ovulation and the processes associated with it would contribute to follicular persistence and to the recurrent appearance of COD.

Inhibition of BMP signaling in P-Cadherin positive hair progenitor cells leads to trichofolliculoma-like hair follicle neoplasias.

BACKGROUND: Skin stem cells contribute to all three major lineages of epidermal appendages, i.e., the epidermis, the hair follicle, and the sebaceous gland. In hair follicles, highly proliferative committed progenitor cells, called matrix cells, are located at the base of the follicle in the hair bulb. The differentiation of these early progenitor cells leads to specification of a central hair shaft surrounded by an inner root sheath (IRS) and a companion layer. Multiple signaling molecules, including bone morphogenetic proteins (BMPs), have been implicated in this process. METHODS: To further probe the contribution of BMP signaling to hair follicle development and maintenance we employed a transgenic mouse that expresses the BMP inhibitor, Noggin, to disrupt BMP signaling specifically in subset of hair follicle progenitors under the control of neuron specific enolase (Nse) promoter. We then studied the skin tumor phenotypes of the transgenic mice through histology, immunohistochemistry and Western Blotting to delineate the underlying mechanisms. Double transgenic mice expressing BMP as well as noggin under control of the Nse promoter were used to rescue the skin tumor phenotypes. RESULTS: We found that the transgene is expressed specifically in a subpopulation of P-cadherin positive progenitor cells in Nse-Noggin mice. Blocking BMP signaling in this cell population led to benign hair follicle-derived neoplasias resembling human trichofolliculomas, associated with down-regulation of E-cadherin expression and dynamic regulation of CD44. CONCLUSIONS: These observations further define a critical role for BMP signaling in maintaining the homeostasis of hair follicles, and suggest that dysregulation of BMP signaling in hair follicle progenitors may contribute to human trichofolliculoma.

Bilateral follicular cysts in a water buffalo.

The present short communication puts on record a case of bilateral, multiple follicular cysts in a water buffalo along with a detailed description of its ovarian biometry and follicular fluid composition. The ovarian weight and biometrical parameters were much higher than in normal cycling buffaloes. A total of three follicular cysts were observed, two on the right ovary and one on the left ovary, measuring 4.9, 3.0 and 2.6 cm yielding 21, 9 and 5 ml of follicular fluid, respectively. The cystic fluid was deep yellow in colour with a viscous consistency. The follicular fluid concentrations of glucose, total protein, cholesterol, acid phosphatase, calcium, phosphorus and progesterone in all the cysts were within the range reported previously in normal buffalo follicular fluid; however, the alkaline phosphatase concentration in cyst 1 and total bilirubin concentration in cysts 1 and 2 were higher than the values in normal follicular fluid. In contrast, the levels of urea nitrogen in cysts 1 and 3, and oestradiol in cyst 3 were lower than the normal values. All the three follicles had an oestradiol to progesterone ratio less than 1. The results of our study suggest that follicular cysts in buffalo are oestrogenically inactive and have an altered concentration of certain biochemical and hormonal constituents.

Reactive oxygen species (ROS): involvement in bovine follicular cysts etiopathogenesis.

Ovulation is compared to an acute inflammatory process during which vasoactive agents, prostanoids, leukotrienes and Reactive Oxygen Species (ROS) develop. The aim of this study was to evaluate the levels of ROS in cystic and follicular fluid, in order to establish their involvement in the etiopathogenesis of Cystic Ovarian Follicle (COF) in dairy cows. The study was conducted in 30 healthy cows (group C) and 30 cows affected by COF (group COF). The fluid of follicular cysts and of preovulatory follicles was drawn by means of ultrasound guided aspiration from the cows of both groups. The fluid obtained was analyzed by a photometric analytical system to detect ROS level. ROS concentration was statistically lower in the cystic fluid than in the follicular one (62.4 +/- 13.36 U.Carr vs. 84.89 +/- 26.99 U.Carr) (p<0.05), thus suggesting that an alteration of the cascade responsible for ROS production may be implicated in the complex etipathogenesis of COF.

Contribution of the VEGF system to the follicular persistence associated with bovine cystic ovaries.

Cystic ovaries (CO) characterize a disorder frequently found in dairy cattle. However, despite the contributions by several researchers, the mechanism that leads to ovulatory failure has not yet been completely elucidated. Thus, the aim of this study was to examine the mRNA expression of bovine vascular endothelial growth factor (VEGFA)-164, VEGFA-164b and VEGF receptors (VEGFR1 and VEGFR2) by real-time PCR and protein expression by immunohistochemistry, immunofluorescence and Western blot in follicular fluid from dairy cows with spontaneous CO and in an experimental model of follicular persistence induced by prolonged treatment with progesterone. Results showed that both VEGFA isoforms and receptors were coexpressed in granulosa and theca interna cells and in follicular fluid of ovaries from all the groups evaluated. VEGFA-164, VEGFA-164b and VEGFR2 protein expression was higher in theca cells of persistent follicles from group P0 (expected time of ovulation) than in those from dominant follicles (as reference structure) from the control group (p < 0.05). Also, VEGFA-164 expression was higher in theca cells of cysts than in those of dominant follicles of the control group (p < 0.05). In follicular fluid, VEGFA-164 expression was higher in persistent follicles from group P5 (5 days of follicular persistence) than in the control, P0 and P15 groups, and higher in cysts than in dominant follicles from the control group (p < 0.05). This study provides evidence of an altered expression of VEGFA-164, VEGFA-164b and VEGFR2 during the formation of persistent follicles and cysts in cows. Together, these results evidence that early development of CO in cows is concurrent with an altered expression of these growth factors and that these alterations may contribute to the follicular persistence, angiogenic dysregulation and ovulatory failure found in cows with follicular cysts.

Merkel cell carcinoma within follicular cysts: report of two cases.

Merkel cell carcinoma is a rare cutaneous neoplasm of unknown histogenesis. Several reports have described the association of Merkel cell carcinoma of the skin with other cutaneous neoplasms within the same lesion, and there are also reports describing three examples of Merkel cell carcinoma within follicular cysts. We describe two examples of Merkel cell carcinoma developed within epithelial cysts. Neoplastic cells of Merkel cell tumor expressed immunoreactivity for chromogranin, synaptophysin, neuron-specific enolase, CAM 5.2 and cytokeratin 20, the last two markers showing the characteristic paranuclear dot-like pattern. In contrast, the epithelial wall lining the cyst and surrounding Merkel cell tumor only expressed immunoreactivity for cytokeratin MNF116. The description of five cases of Merkel cell carcinoma within follicular cysts, including the two cases of this report, support some relationship between Merkel cell tumor and the hair follicle.

Alterations in key metabolic sensors involved in bovine cystic ovarian disease.

High-producing dairy cows frequently suffer metabolic alterations that cause different diseases, which could decrease the reproductive efficiency of the herd. Among these reproductive disorders, cystic ovarian disease (COD) has been related to alterations in metabolites and hormonal factors such as insulin, adiponectin and leptin. The aim of this study was to determine the protein expression of adiponectin and some of its downstream targets in ovarian follicles of control cows and cows with clinical diagnosis of COD. We also analyzed some key metabolic sensors in plasma and follicular fluid from both groups. In follicular cysts, we detected higher protein expression of adiponectin receptor 2 (AdipoR2), 5' adenosine monophosphate-activated protein kinase (AMPK), carnitine palmitoyl transferase 1 (CPT1) and acyl-coenzyme A oxidase 1 (ACOX1) relative to control antral follicles (p < 0.05). This was related to higher plasma adiponectin concentration in cows with COD than in control cows (p < 0.05). On the other hand, insulin concentrations showed an opposite pattern (p < 0.05). Furthermore, we found alterations in local and systemic concentrations of several metabolites. In this regard, in follicular fluid of cystic cows, the concentrations of non-esterified fatty acids and beta-hydroxybutyrate were higher (p < 0.05), whereas the concentrations of glucose and triacylglycerol were lower than in follicular fluid from control cows (p < 0.05). Besides, in both follicular fluid and plasma of cows with COD, the concentration of cholesterol was higher than in control animals (p < 0.05). These results evidence a local altered scenario of some metabolic sensors in cystic follicles, which could generate an adverse microenvironment for the resumption of ovarian activity, possibly causing the persistence of follicles and the recurrence of COD.

Follicular Cysts: A Single Sign and Different Diseases. A View from Comparative Medicine.

Ovarian cystic follicles are the sign of important causes of reproductive failure in numerous species. In this review, some morphological, endocrinological and clinical aspects of cystic follicles in women, cows, mares, sows and bitches are discussed. Follicular cysts are the consequence of the failure of a mature follicle to ovulate at the appointed time of ovulation in the estrous cycle. Although the etiology of follicular cysts remains unknown, this review examines the evidence about the role of endocrine signaling systems in the specific disease or syndrome in each of the species mentioned above. This review also describes, the changes in the pathways of endocrine mechanisms that would trigger disturbances in the intraovarian component underlying the aberrant persistence of follicular cysts. The knowledge of the morphological and endocrinological nature of cystic follicles in different species can provide relevant information to better understand specific diseases when it is integrally analyzed from the comparative medicine viewpoint.

Studies on substantially increased proteins in follicular fluid of bovine ovarian follicular cysts using 2-D PAGE and MALDI-TOF MS.

BACKGROUND: The objective of this study was to identify substantially increased proteins in bovine cystic follicular fluid (FF) in order to clarify the pathology and etiology of bovine ovarian follicular cysts (BOFC). METHODS: Proteins in normal and cystic FF samples were subjected to two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and were compared using silver stained gel images with PDQuest image analysis software. Peptides from these increased spots were analyzed by matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and were identified based on the NCBI database by a peptide mass fingerprinting method. RESULTS: Comparative proteomic analysis showed 8 increased protein spots present in cystic FF. MS analysis and database searching revealed that the increased proteins in cystic FF were bovine mitochondrial f1-atpase (BMFA), erythroid associated factor (EAF), methionine synthase (MeS), VEGF-receptor, glyceraldehydes 3-phosphate dehydrogenase (GAPDH), heat shock protein 70 (HSP70), beta-lactoglobulin (BLG) and succinate dehydrogenase Ip subunit (SD). CONCLUSION: Our results suggest that these proteins are overexpressed in BOFC, and that they may play important roles in the pathogenesis of BOFC. Furthermore, these proteins in the FF could be useful biomarkers for BOFC.

Microvascular distribution and vascular endothelial growth factor expression in bovine cystic follicles.

The aim of this study was to examine the distribution of microvessels in the theca and the expression of vascular endothelial growth factor (VEGF) in the theca and granulosa of cystic follicles. Paraffin sections of cystic follicles were stained with Bandeiraea simplicifolia-I (BS-I) to visualize the endothelial cells of microvessels. The other sections were immunostained with anti-VEGF antibody. The mRNA expression of VEGF in the theca interna of cystic and healthy follicle was determined by RT-PCR. In the theca interna, cystic follicles with granulosa cells had significantly greater microvessel number density (the number of microvessels per given field) and area (area occupied by microvessels per given area) than healthy follicles in various sizes (<3, 4-8, >9 mm). Loss of granulosa cells from cystic follicles resulted in a similar number density, but significantly smaller area of microvessels in the theca interna. There was no significant difference in the microvessel number density and area of the theca externa between the types of follicle. VEGF protein was expressed in the granulosa and theca interna of healthy and cystic follicles. These results demonstrate that cystic follicles have a highly developed vasculature network in the theca interna, especially in cystic follicles containing granulosa cells. It is also suggested that VEGF is highly expressed in the cystic follicle as well as healthy follicle, which may be associated with advanced vasculature and the accumulation of follicular fluid in cystic follicles.

Desmoglein isotype expression in the hair follicle and its cysts correlates with type of keratinization and degree of differentiation.

Within stratified squamous epithelia, such as the epidermis, desmogleins are generally expressed in a differentiation-specific manner. Similar to the epidermis, the hair follicle is compartmentalized into a hierarchy of cell types based on their level of differentiation. Relatively undifferentiated stem cells in the bulge can generate epidermis, sebaceous gland, and hair bulb matrix cells. The latter give rise to at least six different cell types that keratinize as they move up the hair shaft and inner root sheath. Here, we examined expression patterns of the desmoglein isotypes, desmogleins 1, 2, and 3 in the cutaneous epithelium, and discovered that desmoglein 1 and 2 expression correlated with the state of differentiation of defined populations within the hair follicle. Desmoglein 2 was highly expressed by the least differentiated cells of the cutaneous epithelium, including the hair follicle bulge of the fetus and adult, bulb matrix cells, and basal layer of the outer root sheath. In contrast, desmoglein 1 defined more differentiated cell populations, and was expressed in epidermal suprabasal cells, the inner root sheath, and the innermost layers of the outer root sheath. We found that the expression pattern of desmoglein 3 correlated with different types of keratinization. In areas of trichilemmal keratinization in the follicle, and in cysts arising from these areas, desmoglein 3 was expressed throughout all layers of the outer root sheath and cyst wall. In areas of epidermal-like keratinization, such as in the infundibulum and in epidermal inclusion cysts, desmoglein 3 expression was limited mainly to the basal layer. We conclude that desmoglein expression patterns define compartments of cells in similar states of differentiation within the cutaneous epithelium, and reveal a hierarchy of differentiation among these compartments.

Vascular endothelial growth factor and interleukin-8 in ovarian cystic pathology.

OBJECTIVE: To determine the levels of the angiogenic factors vascular endothelial growth factor (VEGF) and interleukin (IL-8) in ovarian cysts. DESIGN: Prospective descriptive study. SETTING: University hospital. PATIENT(S): One hundred women, of whom 9 had ovarian carcinomas, 38 had ovarian endometriomata, 43 had serous ovarian cysts, and 10 had follicular ovarian cysts. INTERVENTION(S): Sampling of serum and ovarian cystic fluid before and during surgery. MAIN OUTCOME MEASURE: Levels of VEGF and IL-8 in cystic fluid and serum. RESULT(S): Levels of both VEGF and IL-8 were found to be significantly higher in the cystic fluid of ovarian carcinomas and endometriomata than in serous and follicular cysts. In endometriomata fluid, levels of VEGF and IL-8 were found to be directly correlated (r = 0.68; P=.0074). Serum levels of VEGF were significantly higher in women with ovarian carcinomas and endometriomata than in those with serous and follicular cysts. Ovarian cancers and endometriomata were similar in terms of cystic concentrations of VEGF and IL-8 and in serum levels of VEGF. CONCLUSION(S): An increase in angiogenic factors that differentiate ovarian carcinomas and endometriomata from other kinds of ovarian pathology is demonstrated.

Involvement of nitric oxide and the ovarian blood follicle barrier in murine follicular cyst development.

OBJECTIVE: To test the involvement of nitric oxide in murine ovarian follicular cysts. DESIGN: Controlled animal study. SETTING: Academic research environment. ANIMAL(S): Immature female B6D2F1 mice at 23 +/- 2 days old. Ovarian cysts were induced by implanting miniosmotic pumps that delivered and maintained constant levels of hCG. Nitric oxide studies included the delivery of nitric oxide synthase (NOS) inhibitors, N(G)-nitro-L-arginine methyl ester (L-NAME), or N(G)-nitro-D-arginine methyl ester, by the same method. Ovulation assays measured cumulus oocyte complexes and blood follicle barrier (BFB) function. RESULT(S): Chronic treatment with hCG induced enlarged ovaries containing multiple follicular cysts, which were approximately double the size of follicles in sham-operated mice. These cysts enclosed few, if any granulosa cells, secreted high levels of testosterone, and had impaired ovarian BFB function. Inhibition of NOS by L-NAME during ovarian cyst formation reduced the size of follicular cysts, sustained normal testosterone levels, and maintained hormonal BFB reactivity in cystic follicles. CONCLUSION(S): Nitric oxide was found to be involved in the formation of hCG-induced murine follicular cysts and complications associated with these cysts were ameliorated by the NOS inhibitor L-NAME.