Relationship between Ovarian Weight and Follicular Population in Heifers

Murasawa, Maya; Takahashi, Tsuyoshi; Nishimoto, Hiromi; Yamamoto, Sawa; Hamano, Seizo; Tetsuka, Masafumi

doi:10.1262/jrd.17014

Cited by 41 publications

(25 citation statements)

References 13 publications

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“…Estimation of OAFPs using the weight of the ovary contralateral to that bearing the corpus luteum (CL) has been described in heifers (MURASAWA et al, 2005). In our study, although the presence of the CL was not evaluated, the strong positive relationship in the number of antral follicles between left and right ovaries is in agreement with previous work by Erickson (1966) and Cushman et al (2009).…”

Section: Discussionsupporting

confidence: 91%

Antral follicles population in heifers and cows of Nelore and Girolando breeds

et al. 2015

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The aim of this study was to evaluate ovarian antral follicle populations (OAFP) of Nelore and Girolando breed heifers (12-18 months old) and cows (24-60 months old). Animals were assigned to four groups: (1) Nelore cows (n = 18), (2) Girolando cows (n = 20), (3) Nelore heifers (n = 7), and (4) Girolando heifers (n = 7). Cows were treated to synchronize follicular wave emergence by implantation of an intravaginal device containing 1.9 g of progesterone, as well as intramuscular administration of 2 mg of estradiol benzoate and 25 mg of dinoprost. This synchronization treatment was administered at a random day of the estrous cycle of each cow, designated D0. Intravaginal devices were removed on D7, and on D11, OAFP counts were performed by transvaginal ovarian ultrasound. For each cow, all follicles ≥3 mm in diameter were counted in both ovaries and counts were performed three times at 35-day intervals. Counts were also obtained from heifers, but these animals were not treated for synchronization of follicular wave emergence. Analysis of variance (ANOVA) with Tukey's test and Pearson's correlation test were used to compare mean OAFPs between counts as well as mean OAFPs between breed and age groups. No differences were observed in mean OAFPs between Nelore and Girolando cows (30.9 vs. 26.7, respectively; P > 0.05) or heifers (16.2 vs. 18.1, respectively; P > 0.05). However, within each breed, there were differences in mean OAFPs between heifers and cows (for Nelore cattle: 16.2 and 30.9, respectively; for Girolando cattle: 18.1 and 26.7, respectively; both P < 0.05). In conclusion, OAFPs were similar between Nelore and Girolando breeds and were influenced by age. Furthermore, we observed a high correlation for individual animals between the mean numbers of follicles counted in both ovaries and total number of follicles counted in either the right or left ovary, indicating that the evaluation of a single ovary is sufficient to estimate the OAFP of an individual. ResumoEste estudo objetivou avaliar a população folicular antral ovariana (PFAO) de novilhas (12 a 18 meses) e vacas (24 a 60 meses) das raças Nelore e Girolando. Os animais foram divididos em quatro grupos: 1) vacas Nelore (n = 18); 2) vacas Girolando (n=20); 3) Novilhas Nelore (n=7) e; 4) Novilhas Girolando (n=7). Nos grupos das vacas, os animais receberam um dispositivo intravaginal com 1.9 g de progesterona, 2 mg de benzoato de estradiol IM e 25 mg de dinoprost IM, em um dia aleatório do ciclo estral (D0). No D7 o dispositivo de progesterona foi retirado. Os animais foram submetidos à ultrassonografia ovariana via transvaginal para contagem da PFAO no D11. Foram contados todos os folículos ≥ 3 mm de diâmetro em ambos os ovários. O procedimento de contagem da PFAO foi repetido três vezes, com intervalos de 35 dias entre as repetições. Para os grupos de novilhas foram adotados os mesmos procedimentos descritos acima, porém estes animais não receberam o tratamento de sincronização da emergência da onda folicular. Para avaliação da PFAO entre as co...

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Section: Discussionsupporting

confidence: 91%

Antral follicles population in heifers and cows of Nelore and Girolando breeds

et al. 2015

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“…Corpora lutea (CLs) were macroscopically assessed for color, vascularity and consistency using published criteria [14] and were classified into four stages (stage I, days 1-4 post ovulation; stage II, days 5-10; stage III, days [11][12][13][14][15][16][17] and stage IV,.…”

Section: Classification Of Corpora Lutea and Folliclesmentioning

confidence: 99%

“…Follicular diameter was estimated from the volume of FF using the equation reported by Murasawa et al [15]. Follicles were classified into five groups based on diameter (≥8.5 mm or <8.5 mm), relative concentrations of estradiol (E2) and progesterone (P4) in FF (E2:P4≥1 or <1), concentrations of glucose in FF (≥45 mg/dl or <45 mg/dl), and the stages of accompanying CLs and follicles (growing follicle, GF; dominant follicle, DF; preovulatory follicle, POF; early atretic follicle, EAF; late atretic follicle, LAF) [16] ( Table 1).…”

Section: Classification Of Corpora Lutea and Folliclesmentioning

confidence: 99%

Gene Expression of 11.BETA.-HSD and Glucocorticoid Receptor in the Bovine (Bos taurus) Follicle During Follicular Maturation and Atresia: The Role of Follicular Stimulating Hormone

et al. 2010

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Abstract. Glucocorticoids modulate ovarian function in cattle. However, their regulatory mechanisms have not been fully elucidated. In the present study, we examined gene expression of two glucocorticoid-metabolizing enzymes, a bidirectional 11β-HSD type 1 (11HSD1) and a dehydrogenase 11β-HSD type 2 (11HSD2), and glucocorticoid receptor (GR) in bovine follicles during follicular maturation and atresia. Granulosa cells (GCs) and theca interna layers (TIs) were harvested from follicles classified as small growing, dominant, preovulatory, early atretic and late atretic follicles. The expression levels of 11HSD1, 11HSD2 and GR mRNA were quantified by real-time PCR. In the healthy follicles, expression of 11HSD1 mRNA increased as follicles matured, both in GCs and TIs. A significant negative correlation was found between the concentration of cortisol in follicular fluid and the level of 11HSD1 mRNA in GCs. The expression of 11HSD2 and GR was either very low or largely unchanged during follicular maturation. In the atretic follicles, a drastic increase in the expression of 11HSD2 was observed both in GCs and TIs. To assess the effect of FSH on the expression of 11HSDs and GR, GCs were cultured with FSH (0-100 ng/ml) for up to 6 days. FSH increased 11HSD1 mRNA in a dose-dependent manner, but not 11HSD2, nor GR. Taken together, these results suggest that developmentally-regulated 11HSD1 plays a pivotal role in modulating the local glucocorticoid environment in maturing bovine follicles. Key words: Bovine, Cortisol, 11β-HSD, Follicle, Glucocorticoid receptor, mRNA (J. Reprod. Dev. 56: [616][617][618][619][620][621][622] 2010) he ovary is a glucocorticoid target organ, and actions of glucocorticoids on ovarian functions have been reported in several species [1]. Glucocorticoids appear to exert both stimulatory and suppressive effects on follicular functions. Glucocorticoids enhance FSH-stimulated progesterone synthesis in cultured granulosa cells (GCs) of rats and cattle [2][3][4][5] and thecal androgen production in cattle [5,6]. Oxytocin production is also stimulated by glucocorticoids in cultured bovine GCs [7]. On the other hand, glucocorticoids have been shown to suppress P450 aromatase (P450arom) activity and decrease the number of LH receptors (LH-R) in rats [2,4], cattle [5] and pigs [8]. These results indicate that glucocorticoid action has to be appropriately regulated to ensure healthy follicular development. The ovary appears to cope with this problem by expressing two glucocorticoid metabolizing enzymes, 11β-HSD type 1 (11HSD1) and type 2 (11HSD2). Research has shown that 11HSD1 is predominantly a reductase that acts as an activator of glucocorticoids (converts inactive glucocorticoids, such as cortisone to cortisol), while 11HSD2 is a dehydrogenase acting as an inactivator [9]. In human and rat preovulatory follicles, GCs predominantly express 11HSD2, which may protect maturing follicles from suppressive effects of glucocorticoids [10][11][12]. The pattern of 11HSD expression appears to be different in ca...

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“…Follicular diameters were estimated from the weight of the FF using the equation y=12.96x 0.31 , where y=the diameter of the follicles (mm) and x= the weight of the FF (g) [22].…”

Section: Classification Of Corpora Lutea and Folliclesmentioning

confidence: 99%

Classification of Bovine Follicles Based on the Concentrations of Steroids, Glucose and Lactate in Follicular Fluid and the Status of Accompanying Follicles

Nishimoto

Hamano²,

Hill

et al. 2009

J. Reprod. Dev.

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Abstract.A simple and clear means to identify the physiological status of follicles is essential for study of follicular biology. In the present study, we verified a novel classification procedure based on analysis of the follicular population and glucose concentration in follicular fluid (FF) as an alternative method to classify bovine follicles. Paired ovaries were collected from heifers, and the number of follicles and stage of the CL were recorded. Follicles were initially divided into the following 3 groups according to diameter and the ratio of E2 and P4 (E/P): E2 active (E-A: E/P≥1), E2 inactive (E-I: E/P<1, ≥8.5 mm) and small follicles (E/P<1, <8.5 mm). E-A follicles were easily identified as E2-rich dominant follicles and were further classified according to diameter and stage of the CL as early dominant (EDF: <8.5 mm), dominant (DF: ≥8.5 mm, stages I-III) or preovulatory follicles (POF: ≥8.5 mm, stage IV). E-I follicles were classified as follows based on the status of the accompanying follicles: early atretic (EAF: without an E-A follicle), mid-atretic (MAF: with an EDF or DF) and late atretic follicles (LAF: with an EAF or POF). The follicular P4 concentrations of the MAF and LAF were significantly higher compared with that of the EAF, while follicular glucose concentration of the LAF was lower compared with those of EAF and MAF, indicating that this classification can be used to distinguish early atretic follicles from more advanced atretic follicles. Small follicles were classified as growing (GF: without E-A follicles) and suppressed small follicles (SSF: with E-A follicles). The SSF was easily identifiable by this procedure, but some GF populations likely contained SSF. To identify true GF, the ratio of E2 in the GF and accompanying EAF may be used. In conclusion, analysis of the follicular population in conjunction with biochemical indices such as steroid and glucose concentrations in FF provides a simple and accurate means of classifying bovine follicles. battoir-derived ovaries have been used extensively as sources of oocytes for embryo production in vitro. Ovaries also provide useful materials for investigating the physiological functions of follicles. Although recent development of ultrasonography enables researchers to monitor development of follicles in real time, follicular samples derived from abattoir-harvested ovaries continue to be cheap and valuable materials for investigating the biochemical natures of follicular fluid (FF) and ovarian functions such as gene/ protein expression. For this reason, a simple and accurate method to determine the physiological status of follicles is necessary. To date, some follicular classification methods have been advocated. These methods are based on morphological, histological and biochemical criteria, but none of them are without faults.Histological examination employs the incidence of pycnosis in granulosa cell nuclei and the degree of granulosa/thecal integrity as the criteria [1]. Although this method is sensitive enough to detect a slight sign o...

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Relationship between Ovarian Weight and Follicular Population in Heifers

Cited by 41 publications

References 13 publications

Antral follicles population in heifers and cows of Nelore and Girolando breeds

Antral follicles population in heifers and cows of Nelore and Girolando breeds

Gene Expression of 11.BETA.-HSD and Glucocorticoid Receptor in the Bovine (Bos taurus) Follicle During Follicular Maturation and Atresia: The Role of Follicular Stimulating Hormone

Classification of Bovine Follicles Based on the Concentrations of Steroids, Glucose and Lactate in Follicular Fluid and the Status of Accompanying Follicles

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