Changes In Ovarian Follicles Research Articles

The Effect of Ajwa Dates (Phoenix dactylifera L) Consumption to Antral Ovarium Imaging by with Ultrasonography (USG) Transvaginal of Perimenopausal Women

Objectives: Perimenopause is a transition from the reproductive period to the menopause stage with a decrease in the number and function of oocytes. Transvaginal ultrasound is a reliable alternative method for detecting ovarian reserve. Ajwa dates contain phenolic and other flavonoid components which are considered to have the potential to improve the ovarian condition of perimenopausal women which can be assessed by increasing the number of antral follicles as measured by transvaginal ultrasound. This study aims to determine the effect of consuming ajwa dates (Phoenix dactylifera L.) on the appearance of ovarian follicles using transvaginal ultrasound in perimenopausal women. Methods: This research is a quasi-experimental study with a pre-post control design carried out at RSIA Sitti Khadijah I Muhammadiyah Makassar, South Sulawesi, Indonesia, from May to September 2023. This research involved 44 perimenopausal subjects aged 42-48 years who were divided into 2 groups randomly (28 intervention groups, 16 control groups). Subjects in the intervention group consumed seven pieces of ajwa dates (60-70 grams each seven pieces) every morning before having breakfast for eight weeks. The transvaginal USG was performed twice, the first was on day three of the menstrual cycle of each subject and the second was after eight weeks of intervention. A comparison of changes in ovarian follicles was analyzed using the Mann-Whitney U test. Results: This study showed a significant decrease in the number of antral follicles in the intervention group and an increase in the number in the control group (p<0.05). Meanwhile, the size of the antral follicles showed a significant increase in the intervention group and a significant decrease in the size of the antral follicles in the control group (p<0.05). Conclusion: Consuming Ajwa dates as an exogenous antioxidant can affect the number and size of antral follicles, which is an indicator of improving the condition of perimenopausal women's ovaries.International Journal of Human and Health Sciences Supplementary Issue 01: 2024 Page: S66

Reduction of ovarian reserves and activation of necroptosis to in vivo air pollution exposures

ABSTRACT We investigated the association between air pollution and changes in ovarian follicles, anti-mullerian hormone (AMH) levels, the occurrence of necroptosis cell death by activation of receptor-interacting protein kinase 3 (RIPK3) and, the activation of mixed lineage kinase domain-like (MLKL) proteins. Forty-two female Wistar rats were divided into three groups of 14 each, which were exposed to real-ambient air, filtered air and purified air (control) in two periods of 3 and 5 months. The results showed that the number of ovarian follicles decreased in the group exposed to real-ambient air versus the control group (P < 0.0001). The trend of age-related AMH changes with respect to exposure to air pollutants was affected and its levels decreased after 3 months of exposure. The MLKL increased in the group exposed to the real-ambient air compared to the control group (P = 0.033). Apparently long-term exposure to air pollution can reduce ovarian reserves.

Long-Term Changes in Ovarian Follicles of Gilts Exposed Neonatally to Methoxychlor: Effects on Oocyte-Derived Factors, Anti-Müllerian Hormone, Follicle-Stimulating Hormone, and Cognate Receptors.

In this paper, we investigated the effects of neonatal exposure to methoxychlor (MXC), a synthetic organochlorine used as an insecticide with estrogenic, antiestrogenic, and antiandrogenic activities on ovarian follicles of adult pigs. Piglets were injected with MXC (20 μg/kg body weight) or corn oil (controls) from postnatal Day 1 to Day 10 (n = 5 per group). Then, mRNA expression, protein abundance and immunolocalization of growth and differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), anti-Müllerian hormone (AMH) and cognate receptors (ACVR1, BMPR1A, BMPR1B, TGFBR1, BMPR2, and AMHR2), as well as FSH receptor (FSHR) were examined in preantral and small antral ovarian follicles of sexually mature gilts. The plasma AMH and FSH levels were also assessed. In preantral follicles, neonatal exposure to MXC increased GDF9, BMPR1B, TGFBR1, and BMPR2 mRNAs, while the levels of AMH and BMP15 mRNAs decreased. In addition, MXC also decreased BMP15 and BMPR1B protein abundance. Regarding small antral follicles, neonatal exposure to MXC upregulated mRNAs for BMPR1B, BMPR2, and AMHR2 and downregulated mRNAs for AMH, BMPR1A, and FSHR. MXC decreased the protein abundance of AMH, and all examined receptors in small antral follicles. GDF9 and BMP15 were immunolocalized in oocytes and granulosa cells of preantral follicles of control and treated ovaries. All analyzed receptors were detected in the oocytes and granulosa cells of preantral follicles, and in the granulosa and theca cells of small antral follicles. The exception, however, was FSHR, which was detected only in the granulosa cells of small antral follicles. In addition, MXC decreased the plasma AMH and FSH concentrations. In conclusion, the present study may indicate long-term effects of neonatal MXC exposure on GDF9, BMP15, AMH, and FSH signaling in ovaries of adult pigs. However, the MXC effects varied at different stages of follicular development. It seems that neonatal MXC exposure may result in accelerated initial recruitment of ovarian follicles and impaired cyclic recruitment of antral follicles.

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Microscopic study on the total number of follicles of ovary in Bangladeshi female cadavers

Context: The ovaries are paired female reproductive and endocrine glands. It is an unique organ in the female body. It undergoes various changes under the influence of hormones which started from prepubertal period and continue up to post menopausal period. Reproductive life span is determined by the histological changes of ovarian follicles. The study was carried out to counting the total number of follicles in relation to age. Study design: Cross sectional, descriptive type of study. Place and period of study: Department of Anatomy, Sir Salimullah Medical College (SSMC), Dhaka from July 2010 to June 2011. Materials: 65 ovaries of Bangladeshi female cadavers age ranging from 5 years to 65 years. Methods: The samples were divided into four different age groups. They were group A or prepubertal group (5-12years), group B or reproductive group (13-45 years), group C or perimenopausal group (46-51years) and group D or postmenopausal group (52-65years). Histological studies were carried out only in right ovary on 24 fresh samples, 6 samples from each group. RESULTS: The mean (±SD) total number of the follicles in the right ovaries were 82.67±2.07, 43.33±8.17, 10.00± 5.47 and 1.17±1.94 per square millimeter in group A, B, C &amp; D respectively. The differences of the mean (±SD) number of the follicles were highly significant (P&lt;0.001) among the all age groups and was significant (P&lt;0.01) when compared between group C with group D. CONCLUSION: Age related changes were observed in the total number of follicles of the ovary. DOI: http://dx.doi.org/10.3329/updcj.v3i1.17979 Update Dent. Coll. j: 2013; 3 (1): 12-17

Molecular cloning, expression analysis and developmental changes in ovarian follicles of goose 3β-hydroxysteroid dehydrogenase 1

The enzyme 3β-hydroxysteroid dehydrogenase/isomerase1 (3βHSD1) can catalyse the conversion of pregnenolone to progesterone in the △4-3-ketosteroid metabolic pathway. The aim of the present study was to clone 3βHSD1 and to determine whether this enzyme in the follicular wall has an effect on yolk progesterone in geese (Anser cygnoides). A putative coding sequence of 3βHSD1, which was 1134 nucleotides in length, was successfully obtained by using reverse transcription polymerase chain reaction (RT–PCR). A comparison of the deduced amino acid sequence with chicken, quail, zebra finch, cattle, horse, pig, human and mouse 3βHSD1 showed 89.7%, 88.4%, 87.3%, 55.6%, 54.0%, 53.5%, 55.3% and 52.9% similarity, respectively. The detection of 3βHSD1 mRNA levels in several tissues by quantitative real-time PCR showed that the highest level of 3βHSD1 was in the adrenal gland, followed by the ovary, which indicated that the gene we obtained was the adrenal gland/gonad-specific one. We measured the level of 3βHSD1 mRNA in the follicular wall and determined the concentration of progesterone in the yolk of these ovarian follicles; the concentration of progesterone in the yolk had a pattern of expression similar to that of 3βHSD1 in the follicular wall during follicular development. This result suggests that the expression of 3βHSD1 in the follicular wall may be a main factor that contributes to the accumulation of yolk progesterone.

ラット培養卵胞を用いたin vitro卵巣毒性検討 ～MEHPにより誘発された多嚢胞性卵巣症候群（PCOS）様変化～

ラット培養卵胞を用いたin vitro卵巣毒性検討 ～MEHPにより誘発された多嚢胞性卵巣症候群（PCOS）様変化～

Dynamic changes in ovarian follicles measured by ultrasonography during gonadotropin stimulation in rhesus monkeys

The objective was to study dynamic changes of ovaries in rhesus macaques stimulated by gonadotropins to identify an indicator for predicting ovarian response to stimulation. Twenty-one cycling monkeys were given 36 IU/d recombinant human follicle-stimulating hormone (rhFSH) for 8 d. Animals (n = 17) with ≥5 follicles (≥3 mm) in their ovaries on Day 9 of ovarian stimulation were deemed good responders, whereas those with a lesser response were poor responders (n = 4). For these two groups, the mean (±SD) numbers of oocytes retrieved were 44.3 ± 21.4 and 11.0 ± 4.6, respectively. In retrospect, the mean diameters of the ovaries and of the largest follicles, the total number of detectable follicles (diameter >0.5 mm), and serum estradiol concentrations gradually increased during the stimulation period in the good responders but did not increase in the poor responders. Comparing good and poor responders, the number of ovarian follicles >0.5 mm already exhibited a difference (12.9 ± 6.5 vs. 2.9 ± 1.3, respectively, P < 0.05) on Day 1 of stimulation. However, for other end points, differences were not significant until at least Day 5. Moreover, good responders yielded a fivefold higher blastocyst development rate than that of poor responders (P < 0.01). In conclusion, the number of ovarian follicles detected with ultrasonography could be useful to predict the response to FSH stimulation in non-human primates.

The ‘beneficial’ adipokines in reproduction and fertility

The objective of this study was to review the available information on the signaling proteins produced by adipose tissue in the context of their role in regulating reproductive processes, including ovarian and uterine function. It is well known that both obesity and excessive leanness are associated with reproductive dysfunction. Adipokines are cytokines predominantely or exclusively expressed by adipose tissue that circulate and affect target tissues. Four known adipokines, adiponectin, visfatin/PBEF, omentin and vaspin, all increase tissue sensitivity to insulin, and are thus described as 'beneficial'. There is strong support for a role for adiponectin in the function of the ovary and placenta. There is evidence for direct effects of this adipokine on the late stages of folliculogenesis, and additive interactions of adiponectin with insulin and gonadotropins in inducing periovulatory changes in ovarian follicles. In addition, clinical and genomic studies associate hypoadiponectinemia with obesity-related reproductive disorders, including the polycystic ovarian syndrome. The roles for visfatin/PBEF, omentin and vaspin in reproduction remain to be established. The conclusion thus drawn is that the expression of insulin-sensitizing adipokines varies with adipose abundance. These adipokines have demonstrated both the potential effects on ovarian function and the possible effects on the formation of the placenta, acting through multiple mechanisms.

Growth and histology of ovarian follicles after cold storage in the tammar wallaby

Cold storage is a simple method for storing and transporting tissues and organs. The reliability of this method for maintaining structure and function of marsupial ovarian tissue was assessed using histological techniques and follicle culture. Tammar wallaby ovaries were placed in cold storage (phosphate-buffered saline at 4 degrees C) for 24 or 48 h. Although necrotic changes were evident in the germinal epithelium, cortex and interstitial tissue after cold storage, there was little evidence of necrotic changes in ovarian follicles and oocytes appeared normal. Secondary follicles isolated from ovarian tissue after cold storage grew by a similar amount to non-stored follicles when cultured for 4 days in vitro, but no follicles from any group developed to tertiary follicles. Cold storage for up to 24 h had little obvious effect on the structure of ovarian tissue and follicles isolated from this tissue maintained their structure during culture. However, degeneration in culture increased with storage time and was significantly higher after cold storage for 48 h. As demonstrated in the tammar wallaby, cold storage has potential as a method for storage and transport of marsupial ovaries up to 24 h.

The Effect of Human Chorionic Gonadotropin on the Development and Function of Bovine Corpus Luteum.

Proceeding with research into human chorionic gonadotropin (hCG) administration, designed to promote pregnancy rates in embryo transfer, hCG was administered to bovine recipients on the day of ovulation in Holstein cows and the day of selection of recipients, ie., day prior to embryo transfer (5 days after the day of ovulation), and the changes in ovaries and the concentrations of plasma progesterone (P) and estradiol-17β (E2) levels after administration were determined. Changes in the ovaries and functions of blood P and E2 levels after administration were determined in order to investigate the effects of hCG on increase in luteinization and functions of P secretion. Nine Holstein dairy cows were divided into two groups. All 4 cows of one group received an intramuscular injection of saline at a dose of 5 ml on the day of ovulation (Day 0-control group: the day of ovulation was designated as Day 0), which was followed by an injection of hCG at a dose of 1,500 IU on the corresponding day of the next estrous cycle (Day 0-hCG group). In a similar way, 4 cows in the other group received an injection of saline at a dose of 5 ml on day 5 (Day 5-control group), then 3 of the 4 cows and the remaining cow received intramuscular injections of hCG at a dose of 1,500 IU on the corresponding day of the next estrous cycle (Day 5-hCG group). These cattle were examined for changes in ovarian follicles and corpus luteum (CL) every day or every other day by rectal palpation and ultrasonography, and blood samples were collected every day for the P and E2 analysis. The estrous cycle lengths in the hCG groups tended to be slightly longer than those in the control group, though the difference was not significant. In the Day 5-hCG group, ovulation was induced in all cows 1 or 2 days after hCG administration, and was followed by the development of new CL (induced CL). Ultrasonographic observations revealed that the total luteal tissue area of the CL periodicum and the induced CL in the Day 5-hCG group were significantly (P<0.05) wider than those in the Day 5- control group from 3 days after hCG administration onward. Plasma P levels started rising 3 hours after hCG administration in the Day 5-hCG group, and they were significantly (P<0.05) higher than those in the Day 5-control group on days 6, 7, 12, 13 and 14, respectively. Plasma E2 levels decreased rapidly after hCG administration in the Day 5-hCG group, and were lower than those in the Day 5-control group. These results showed enhancement of the luteal activity and a decrease in plasma E2 level by hCG administration 5 days after ovulation, suggesting that the hCG treatment on the day prior to embryo transfer is effective at increasing the pregnancy rate in embryo transfer.

Effects of accelerated photoperiod regimes on the reproductive cycle of the female rainbow trout: II seasonal variations of plasma gonadotropins (GTH I and GTH II) levels correlated with ovarian follicle growth and egg size

Female rainbow trout were exposed over their second reproductive cycle to a simulated natural photoperiod (control group) and to two accelerated photoperiod regimes (S9 and S6 groups). Early spawning was achieved in both accelerated groups, coupled, however, with a reduction of mean egg size. To investigate this reduction of egg size, circulating levels of GTHs and two indices of ovarian growth (gonadosomatic index and follicle diameter) were regularly measured in association with histological studies of structural changes in ovarian follicles. Regardless of the photoperiod regime, the seasonal profile of plasma GTH I levels appeared to be multiphasic. The successive transient elevations in GTH I levels appeared to be connected with the initiation of ovarian growth and vitellogenesis and also, with the synchronization of the late stages of maturation and ovulation. In contrast, the seasonal profile of plasma GTH II levels was monophasic, with a single peak at ovulation, confirming that GTH II is not associated with ovarian growth but promotes gamete maturation and release. Our results demonstrate that the reduction of egg size cannot be due to a deficient secretion of GTH I in plasma, since GTH I levels were much higher during vitellogenesis in both accelerated groups, but rather to an alteration of ovarian follicle growth during the late stages of vitellogenesis. Finally, the early and middle stages of ovarian growth appeared to be photosensitive periods, whereas the late stages were less so, and appeared to be controlled rather by an endogenous biological clock synchronized by the photoperiod.

Changes in ovarian follicles following acute infection with bovine viral diarrhea virus

Bovine viral diarrhea virus (BVDV) has been associated with several reproductive problems in cattle, including poor fertility, early embryonic deaths, abortion and congenital anomalies. Little is known about the cause of poor fertility in cows acutely infected with BVDV. The purpose of this study was to identify changes in ovarian function following acute infection with noncytopathic BVDV. The ovaries of 5 BVDV sero-negative and virus-negative pubertal heifers were monitored daily for 4 consecutive estrous cycles. The position and diameter of all follicles (>5mm) and luteal structures were recorded. Daily plasma samples were collected to measure peripheral progesterone and estradiol levels. Each heifer was infected intranasally with noncytopathic BVDV following ovulation of the second estrous cycle. The maximum diameter and growth rate of dominant anovulatory and ovulatory follicles were significantly reduced following acute BVDV infection. Similarly, the number of subordinate follicles associated with both the anovulatory and ovulatory follicle was reduced following infection. There were no significant differences in other follicle or luteal dynamic parameters or in peripheral progesterone or estradiol levels. Ovarian follicular growth was different during the first 2 estrous cycles following acute infection with BVDV when compared with the 2 estrous cycles preceding infection. These differences may be important in explaining reduced fertility in herds with acute BVDV infection.

Histological populations and atresia of ovarian follicles in postpartum cattle treated with an agonist of gonadotropin-releasing hormone.

Surface and histological changes of ovarian follicles and degree of atresia were characterized 3 and 6 d after a treatment with a GnRH agonist (buserelin) in postpartum beef cows. Sixteen cyclic cows on d 7 of their estrous cycle and eight acyclic cows were used. On d 0 of the experimental period, eight cyclic cows were injected with 2 mL of physiological saline and the remaining eight cyclic cows and the acyclic cows were injected i.m. with 8 micrograms of buserelin. Ovaries were collected 3 or 6 d later (n = 4 cows per group per day). All follicles (> 1.57 mm) were observed microscopically, measured using routine histological techniques, and classified as either nonatretic or atretic, with early or late atresia, and grouped into Class 1, 1.57 to 3.67 mm, Class 2, 3.68 to 8.56 mm, or Class 3, > 8.56 mm. Buserelin induced formation of new corpora lutea in all cows but one (acyclic cow). Class 1 follicles decreased on d 3 but increased on d 6 (day x treatment, P < .004), whereas those of Class 2 increased (P < .07) on both d 3 and 6 after buserelin treatment. However, within Class 2 follicles, we detected an increase on d 3 and 6 in the number (P < .01) and proportion (P < .07) of atretic follicles, an increase in the number of follicles in late atresia on d 6 (day x treatment, P < .03), and a decrease in the number (P < .06) and proportion (P < .03) of nonatretic follicles on d 6 (day x treatment).(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in ovarian follicles and in vitro sex hormone release in the lizard Podarcis sicula sicula

An in vitro superfusion method was used to test sex hormone release from different kinds of ovarian follicle (growing follicles, postovulatory follicles, and atretic follicles) in the lizard Podarcis sicula sicula. Sex hormone output changes with the stage of follicle evolution and sexual cycle. Previtellogenetic follicles prevail in early-spring quiescent ovaries and secrete mainly progesterone, which is probably utilized at that phase to delay ovarian resumption. In the acute ovary, progesterone output from previtellogenetic follicles decreases, whereas vitellogenetic follicles produce a significant amount of 17 beta-estradiol, which is necessary for sustaining vitellogenin synthesis by the liver and oviduct growth. As follicles become ripe, progesterone production is resumed, and it increases in young postovulatory follicles. This is in line with the functions assigned to the hormone at that phase of the sexual cycle, i.e., the induction of oocyte maturation and the regulation of egg retention in the oviduct. Postovulatory follicles can also synthetize 17 beta-estradiol. After oviposition, this hormone, which is secreted by the old postovulatory follicles, can reinitiate vitellogenin synthesis, allowing the development of a new oocyte set. Our data confirm that active, although ephemeral, corpora lutea are also formed in oviparous species. A limited contribution to ovarian sex steroid production derives also from atretic follicles, at least at the early stages of the breeding cycle.

In-vitro effects of angiotensin II on steroid production by hamster ovarian follicles and on ultrastructure of the theca interna.

Angiotensin II (AII) is present in the mammalian ovary and has been correlated with atresia in follicles. Since the theca interna may be one site at which atresia is initiated, we wished to determine whether AII exerts an effect on theca interna from explanted ovarian follicles of hamsters. Hamsters were sacrified on the morning of proestrus, and ovaries were removed. Preovulatory follicles were excised from the ovaries, and cultured with one of the following components: medium alone (control); medium plus AII (1 x 10(-6) M); the AII-receptor antagonist [Sar1, Ile8] AII (1 x 10(-4) M); or AII plus antagonist. After 72 h, the follicles were processed for transmission electron microscopy (to determine quantities of theca interna organelles involved in the steroid synthetic pathway) or for protein determination (to normalize steroid production rates). The incubation medium was drawn off and analyzed by radioimmunoassay for progesterone, androstenedione, or estradiol-17 beta. There was a significant positive correlation (r = 0.92, P less than 0.01) between follicular androstenedione secretion and area comprising theca interna smooth endoplasmic reticulum. In the theca interna, AII induced a two-fold and 1.6-fold increase in lipid droplet number and area comprising smooth endoplasmic reticulum, respectively (P less than 0.05). Excess antagonist negated the increase in cell organelles and also reduced androstenedione secretion compared with AII alone (P less than 0.05). Most importantly, AII significantly augmented the ratio of androstenedione:estradiol-17 beta secretion by 44% over that of control. The ultrastructural changes observed in this study and the increase in the androstenedione:estradiol-17 beta production ratio are consistent with atresia-like changes in ovarian follicles.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural evidence for estradiol synthesis in the ovary of persistent-estrous rats exposed to continuous illumination.

The relation between sex hormone levels in blood and ultrastructural changes of ovarian follicles was examined in persistent-estrous rats exposed to continuous illumination (LL) for 100 days. Plasma LH showed a tonic level secretory pattern, and circulating estradiol and estrone concentrations were relatively high, while both levels of FSH and progesterone were low. Various stages of growing and degenerating follicles were observed in the ovary of the LL-exposed rats. The early stage of antral follicle did not seem to possess the ability of steroidogenesis. Theca cells around mature antral follicles contained prominent Golgi apparatuses, plenty of smooth endoplasmic reticulum (ER), abundant free ribosomes and many round-mitochondria. A few newly formed lipid droplets were seen in some of theca cells. Granulosa cells contained much distended rough ER, well-developed mitochondria, several lipid droplets and microfilaments. The theca cells of abnormal follicles with hyperplastic and infolded layers of granulosa cells contained many lipid droplets. However, the development of the smooth ER became hindered with increasing lipid droplets in the theca cell. On the other hand, granulosa cells of abnormal follicles contained greater numbers of lipid droplets than those of antral mature follicles, and were equipped with well-developed cytoplasmic organelles as were those of mature antral follicles. Theca interna cells of abnormal follicles may be more involved in the secretion of androgen, which has already been accumulated in the lipid droplets, than the cells involved in the active synthesis of the hormone, while the granulosa cells may convert its androgen to estrogen. The present findings suggest that both follicles of mature and abnormal types in the LL-exposed rat retain enough capacity of estradiol production and participate in the continued elevation of circulating estradiol, probably resulting in the stimulation of the theca cells by the tonic level of LH and of the granulosa cells by the levels of FSH, which are lower than the basal values during the normal 4-day estrous cycle.

Correlation of plasma estradiol-17 beta and progesterone levels with ultrastructure and histochemistry of ovarian follicles in the white-spotted char, Salvelinus leucomaenis.

Plasma estradiol-17 beta and progesterone profiles were correlated with morphological changes in ovarian follicles during the preovulatory and postovulatory periods in the white-spotted char, Salvelinus leucomaenis, Plasma estradiol levels were highest in September, and were followed by a sharp drop in October; they remained very low throughout the postovulatory period. There was a good correlation between plasma estradiol levels and the gonadosomatic index, thus suggesting that estradiol is responsible for the synthesis of vitellogenic proteins. Plasma progesterone levels were very low in August, began to rise in September and reached a peak soon after ovulation; progesterone remained high for several days after ovulation. A preovulatory rise in plasma progesterone levels was recorded, and this is discussed in relation to the induction of oocyte maturation. In the preovulatory follicles, neither granulosa cells nor special thecal cells (ST cells) showed delta 5, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity. In the young postovulatory follicles, in contrast, the ST cells showed intense 3 beta-HSD activity with extensive agranular endoplasmic reticulum and numerous large mitochondria, while granulosa cells did not show 3 beta-HSD activity. These results strongly suggest that the ST cells are the major sites of progesterone synthesis during the postovulatory period.

Reproductive Hormones Associated with Normal and Abnormal Changes in Ovarian Follicles in Postpartum Dairy Cows

Concentrations of reproductive hormones and ovarian changes were monitored every 4 days during the postpartum period in 35 dairy cows. The cows were classified as either control (22 cows) or cystic (13 cows) based on per rectum examination of the ovaries. Control cows were detected with a corpus luteum after the first postpartum ovulation while in cystic cows, ovarian follicles of at least 2.5cm in diameter persisted in the absence of a corpus luteum for at least 14 days. The mean postpartum interval to the first follicle 1.5 to 2.0cm in diameter was about 16 days for both groups. Ovulation was detected earlier postpartum for cows in the control group (18.4±1.7 days) than for cows in the cystic group (36.3±2.7 days). Luteinizing hormone in plasma increased during the early postpartum period (days 1 to 10) for both groups, but mean concentrations of luteinizing hormone, progesterone, and estradiol-17β in plasma were not different between groups then or on days −8, −4, or 0 (day of the first postpartum follicle 1.5 to 2.0cm in diameter). During this period (days −8 to 0), estradiol-17β and luteinizing hormone in plasma were correlated positively, but regression coefficients differed between groups. These results suggest a partial hypothalamic and/or pituitary failure in releasing pituitary luteinizing hormone as a cause for postpartum ovarian cysts.

Anatomical Indicators for Assessing Age of Mosquitoes:1 Changes in Ovarian Follicles

Some changes in ovaries that occur with physiological aging are presented for Aedes nigromaculis (Ludlow) and the southern house mosquito, Culex pipiens quinquefasciatus Say (Diptera: Culicidae). Differentiation of the oöcytes took place in both species before blood-feeding, and follicular development was arrested in either Stage I or Stage II. Oocytes matured after a single blood meal independently of insemination. Rates of ovarian development at 3 temperatures are given for the 2 species, as are observations on digestion of blood. The formation and occurrence of dilatations on follicular pedicels are described; some exceptions to the direct correlation between numbers of dilatations and numbers of completed ovarian cycles are pointed out. Observations on some other species of mosquitoes are included.