Talk:Estrous Cycle

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Cite this page: Hill, M.A. (2024, June 14) Embryology Estrous Cycle. Retrieved from


Liman N & Ateş N. (2020). Abundances and localizations of Claudin-1 and Claudin-5 in the domestic cat (Felis catus) ovary during the estrous cycle. Anim. Reprod. Sci. , 212, 106247. PMID: 31864490 DOI.

Abundances and localizations of Claudin-1 and Claudin-5 in the domestic cat (Felis catus) ovary during the estrous cycle.

Abstract Claudins (CLDNs) are major Ca2+-independent cell adhesion molecules functioning at tight junctions (TJ). The presence and localization of cell adhesion molecules are important for understanding the mechanisms associated with follicular and luteal development in the ovary. In this study, there was an examination of whether CLDN-1 and CLDN-5 are present in a cell- and stage-specific manner during follicular and luteal development in the domestic cat ovary using immunohistochemistry and Western blot analysis. While results from immunoblot analyses revealed there were relatively similar abundances of CLDN-5 protein in three phases of the ovarian cycle, the abundance of CLDN-1 in the luteal phase was greater than those measured in the follicular and anestrous phases (P < 0.01). Results with immunohistochemistry indicate CLDN-1 and -5 are mainly localized in the cell nuclei and cytoplasm of all tissues of the cat ovary. In follicles, throughout the development from primordial to large antral follicles, CLDN-1 and -5 were present in oocytes, and the granulosa and theca cell layers. In follicles at all stages of atresia, there were cell-type and stage-specific protein distributions with immunostaining present in granulosa, thecal interstitial, and fibroblast-like cells. In corpora lutea, both small and large luteal cells stained positively for both claudins. In conclusion, the specific presence and localization patterns of CLDN-1 and -5 in the cat ovary is suggestive that these TJ proteins could have local functions in the regulation of most ovarian functions such as follicle development and atresia, ovulation, and corpus luteum formation and regression. Copyright © 2019 Elsevier B.V. All rights reserved. KEYWORDS: Claudins; Domestic cat; Ovary PMID: 31864490 DOI: 10.1016/j.anireprosci.2019.106247


Kutzler MA. (2018). Estrous Cycle Manipulation in Dogs. Vet. Clin. North Am. Small Anim. Pract. , 48, 581-594. PMID: 29709316 DOI.

Estrous Cycle Manipulation in Dogs.

Abstract Since 1939, scientists have studied estrous cycle manipulation in dogs resulting in more articles published in this field that any other area of canine reproduction. Estrous cycle manipulation in dogs must be safe and reliable. Dopamine agonists, gonadotropin-releasing hormone agonists, and gonadotropins are hormones that have been used for estrus induction in bitches but each treatment has advantages and disadvantages. Despite widespread availability of these medications throughout the rest of the world, there are no drugs currently labeled for canine estrus induction in the United States. Copyright © 2018 Elsevier Inc. All rights reserved. KEYWORDS: Dopamine agonist; Estrus induction; Gonadotropin releasing hormone (GnRH) agonist PMID: 29709316 DOI: 10.1016/j.cvsm.2018.02.006


Cora MC, Kooistra L & Travlos G. (2015). Vaginal Cytology of the Laboratory Rat and Mouse: Review and Criteria for the Staging of the Estrous Cycle Using Stained Vaginal Smears. Toxicol Pathol , 43, 776-93. PMID: 25739587 DOI.

Vaginal Cytology of the Laboratory Rat and Mouse: Review and Criteria for the Staging of the Estrous Cycle Using Stained Vaginal Smears.

Abstract Microscopic evaluation of the types of cells present in vaginal smears has long been used to document the stages of the estrous cycle in laboratory rats and mice and as an index of the functional status of the hypothalamic-pituitary-ovarian axis. The estrous cycle is generally divided into the four stages of proestrus, estrus, metestrus, and diestrus. On cytological evaluation, these stages are defined by the absence, presence, or proportion of 4 basic cell types as well as by the cell density and arrangement of the cells on the slide. Multiple references regarding the cytology of the rat and mouse estrous cycle are available. Many contemporary references and studies, however, have relatively abbreviated definitions of the stages, are in reference to direct wet mount preparations, or lack comprehensive illustrations. This has led to ambiguity and, in some cases, a loss of appreciation for the encountered nuances of dividing a steadily moving cycle into 4 stages. The aim of this review is to provide a detailed description, discussion, and illustration of vaginal cytology of the rat and mouse estrous cycle as it appears on smears stained with metachromatic stains. © 2015 by The Author(s). KEYWORDS: diestrus; estrus; metestrus.; proestrus PMID: 25739587 DOI: 10.1177/0192623315570339

Progesterone, estradiol, arachidonic acid, oxytocin, forskolin and cAMP influence on aquaporin 1 and 5 expression in porcine uterine explants during the mid-luteal phase of the estrous cycle and luteolysis: an in vitro study

Reprod Biol Endocrinol. 2015 Feb 18;13(1):7.

Skowronska A1, Młotkowska P2, Wojciechowicz B3, Okrasa S4, Nielsen S5, Skowronski MT6,7.


BACKGROUND: The cell membrane water channel protein, aquaporins (AQPs), regulate cellular water transport and cell volume and play a key role in water homeostasis. Recently, AQPs are considered as important players in the field of reproduction. In previous studies, we have established the presence of AQP1 and 5 in porcine uterus. Their expression at protein level altered in distinct tissues of the female reproductive system depending on the phase of the estrous cycle. However, the regulation of aquaporin genes and proteins expression has not been examined in porcine uterine tissue. Therefore, we have designed an in vitro experiment to explain whether steroid hormones, progesterone (P4) and estradiol (E2), and other factors: oxytocine (OT), arachidonic acid (AA; substrate for prostaglandins synthesis) as well as forskolin (FSK; adenylate cyclase activator) and cAMP (second messenger, cyclic adenosine monophosphate) may impact AQPs expression. METHODS: Uterine tissues were collected on Days 10-12 and 14-16 of the estrous cycle representing the mid-luteal phase and luteolysis. Real-time PCR and Western blot analysis were performed to examine the expression of porcine AQP1 and AQP5. Their expression in the uterine explants was also evaluated by immunohistochemistry. RESULTS: The results indicated that uterine expression of AQP1 and AQP5 potentially remains under control of steroid hormones and AA-derived compounds (e.g. prostaglandins). P4, E2, AA, FSK and cAMP cause translocation of AQP5 from apical to the basolateral plasma membrane of the epithelial cells, which might affect the transcellular water movement (through epithelial cells) between uterine lumen and blood vessels. The AC/cAMP pathway is involved in the intracellular signals transduction connected with the regulation of AQPs expression in the pig uterus. CONCLUSIONS: This study documented specific patterns of AQP1 and AQP5 expression in response to P4, E2, AA, FSK and cAMP, thereby providing new indirect evidence of their role in maintaining the local fluid balance within the uterus during the mid-luteal phase of the estrous cycle and luteolysis in pigs.

PMID 25884220


The expression pattern of microRNAs in granulosa cells of subordinate and dominant follicles during the early luteal phase of the bovine estrous cycle

PLoS One. 2014 Sep 5;9(9):e106795. doi: 10.1371/journal.pone.0106795. eCollection 2014.

Salilew-Wondim D1, Ahmad I1, Gebremedhn S1, Sahadevan S1, Hossain MD2, Rings F1, Hoelker M1, Tholen E1, Neuhoff C1, Looft C1, Schellander K1, Tesfaye D1.


This study aimed to investigate the miRNA expression patterns in granulosa cells of subordinate (SF) and dominant follicle (DF) during the early luteal phase of the bovine estrous cycle. For this, miRNA enriched total RNA isolated from granulosa cells of SF and DF obtained from heifers slaughtered at day 3 and day 7 of the estrous cycle was used for miRNAs deep sequencing. The results revealed that including 17 candidate novel miRNAs, several known miRNAs (n = 291-318) were detected in SF and DF at days 3 and 7 of the estrous cycle of which 244 miRNAs were common to all follicle groups. The let-7 families, bta-miR-10b, bta-miR-26a, bta-miR-99b and bta-miR-27b were among abundantly expressed miRNAs in both SF and DF at both days of the estrous cycle. Further analysis revealed that the expression patterns of 16 miRNAs including bta-miR-449a, bta-miR-449c and bta-miR-222 were differentially expressed between the granulosa cells of SF and DF at day 3 of the estrous cycle. However, at day 7 of the estrous cycle, 108 miRNAs including bta-miR-409a, bta-miR-383 and bta-miR-184 were differentially expressed between the two groups of granulosa cell revealing the presence of distinct miRNA expression profile changes between the two follicular stages at day 7 than day 3 of the estrous cycle. In addition, unlike the SF, marked temporal miRNA expression dynamics was observed in DF groups between day 3 and 7 of the estrous cycle. Target gene prediction and pathway analysis revealed that major signaling associated with follicular development including Wnt signaling, TGF-beta signaling, oocyte meiosis and GnRH signaling were affected by differentially expressed miRNAs. Thus, this study highlights the miRNA expression patterns of granulosa cells in subordinate and dominant follicles that could be associated with follicular recruitment, selection and dominance during the early luteal phase of the bovine estrous cycle.

PMID 25192015 [PubMed - in process] PMCID: PMC4156418









A quantitative method for assessing stages of the rat estrous cycle

Biotech Histochem. 2005 Mar-Apr;80(2):79-87.

Hubscher CH, Brooks DL, Johnson JR. Source Department of Anatomical Sciences & Neurobiology, University of Louisville, Louisville, Kentucky 40292, USA. Abstract The impact of gender and/or hormone variations on a wide variety of neural functions makes the choice between studying males or females (or both) of a given species difficult. Although female rats are widely used experimentally, few studies control for the stage of estrus. More detailed information about how to distinguish the various stages of the estrous cycle is needed. For the present study, vaginal smears were obtained once a day and stained using an adaptation of the Papanicolaou (PAP) procedure. Images are provided of unstained "wet" samples and the corresponding PAP stained smears illustrating the cellular profile for each stage of the cycle as well as post-ovariectomy. The different cell populations across the cycle were quantified and ratios determined to show trends between the predominant and other cell types in each stage of the estrous cycle. Both stained and unstained images and cell quantification data provide valuable guidelines for distinguishing the stages of the estrous cycle.

PMID 16195173