• Journal of Veterinary Clinics
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• v.38 no.4
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• pp.199-203
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• 2021

A 4-year-old Thoroughbred mare was brought to the Korea Racing Authority Equine Hospital with heightened sensitivity to touch of the hindquarter, reluctance to step forward, frequent urination even during training, clitoral winking, tail swinging, tail lifting, and training difficulties due to being in constant heat. The trainer claimed that she was in heat and exhibited reduced performance. Physical and lameness examinations revealed no abnormality. Rectal palpation and transrectal ultrasonography revealed normal reproductive organs and estrus. As she exhibited typical estrous behavior without any other physical conditions, the mare was considered to express undesirable estrous behavior. An intrauterine glass ball was inserted into the mare on ovulation day. However, the estrous behaviors were reduced unsatisfactorily. Additionally, 1 mL of peanut oil was administered on the 10th day after the intrauterine device insertion. The mare returned to training and expressed no undesirable estrous behavior over 30 days after the peanut oil treatment. However, further follow-ups were not conduct as the mare was retired to a farm after a limb injury occurred during training. This is the first report of undesirable estrous behavior in a Thoroughbred mare under the rules of racing in Korea. It is recommended that equine clinicians in Korea consider peanut oil as a therapeutic agent to control mares' estrous behavior-related problems.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.307-311
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• 2016

The aim of this study was to compare the appearance rate of vaginal cytology during estrous cycle in small pet bitches. A characteristic features of vaginal cytology during the estrous cycle were the high proportion of superficial cell in proestrus, anuclear cell in estrus, small intermediate cell in diestrus, and small intermediate cell in anestrus, respectively. There were no statistically significant differences of appearance rate of vaginal cytology among small pet bitches in the each phase of estrous cycle. These results indicated that the vaginal cytology was useful method for estimating estrous cycle and optimal breeding time in small pet bitches.

• Journal of Embryo Transfer
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• v.31 no.4
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• pp.323-333
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• 2016

Pro-inflammatory cytokines, interleukin-$1{\beta}$(IL1B), IL6, and tumor necrosis factor-alpha (TNF), are known to play important roles in regulating the endometrial function in the uterus during the estrous cycle and pregnancy in several species. However, the expression and function of these cytokines and their receptors in the uterine endometrium during the estrous cycle have not been studied in pigs. Thus, this study determined the expression and regulation of IL1B, IL6, TNF and their respective receptors, IL1R1, IL1RAP, IL6R, GP130, TNFRSF1A, and TNFRSF1B during the estrous cycle in pigs. To analyze levels of each gene expression in the uterine endometrium we obtained from endometrial tissues on Days 0, 3, 6, 9, 12, 15, and 18 of the estrous cycle. Real-time RT-PCR analysis showed that levels of IL1B, IL1RAP, IL6R, GP130, TNF, TNFRSF1A, and TNFRSF1B mRNAs were highest on Day 15 or 18 of the estrous cycle, which corresponds to the proestrus period. Levels of IL1R1 were highest on Day 0, while levels of IL6 were biphasic with high levels on Day 6 and Day 15. The abundance of IL1B, IL6, IL6R, and TNF mRNAs was decreased by progesterone, while levels of GP130 were increased by progesterone in endometrial tissue explants. These results showed that expression of pro-inflammatory cytokines and their receptors changed stage-specifically during the estrous cycle and regulated by progesterone in the uterine endometrium in pigs, suggesting that these pro-inflammatory cytokines may be involved in the regulation endometrial function during the estrous cycle in pigs.

• Korean Journal of Veterinary Research
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• v.12 no.1
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• pp.133-139
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• 1972

Estrous and non-estrous rabbits were inoculated with E. coli or Streptococcus pyogenes, and the mixture of the two organisms, and bacterial count and histopathological studies of uterine horns were made to observe the effects of estrogen on the resistance of the uterus to bacterial infection. The results obtained were summarized as followings; 1. Four hours after inoculation of bactoria into uterine horn, the number of organisms was significantly lower in estrous rabbits than in non-estrous regardless of the kind of organisms inoculated. 2. The highest reduction rate of the organisms among the three bacterial inoculation groups was found in estrous rabbits inoculated with E. coli, and the lowest reduction rate was with Streptococcus pyogenes. 3. Histopathological changes of uterine horns induced five days after bacterial inoculation were observed. In estrous rabbits, a mild inflammatory reaction was found in Streptococcus pyogenes group, but a slight inflammatory reaction and only a negligible inflammatory reaction were observed in mixed bacteria group, and in E. coli group respectively. In non-estrous group, however, a marked inflammatory reaction was observed in Streptococcus pyogenes group, a moderate inflammatory reaction and a slight inflammatory reaction were observed in the mixed bacterial group and E. coli group, respectively.

• Korean Journal of Animal Reproduction
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• v.14 no.3
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• pp.175-182
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• 1990

Behavioural estrus and short estrous cycles were observed and serum concentrations of estradiol-17$\beta$(E2) before and after of estrous were measured following superovulation treatments in 30 pluriparous Korean native goats. The goats were divided into 2 groups. Fifteen goats were injected IM with 1,000IU PMSG on Day 12 of the estrous cycle followed by 10mg PGF2$\alpha$ 48h later(P4＋PMSG), and the other 15 goats were injected IM with 10mg progesterone(P4)in oil once daily for 10d beginning at any days of estrous cycle followed by 1,000IU PMSG and 10mg PGF2$\alpha$ at the 8th day of progesterone treatment(P4＋PMSG group). After injection of PGF2$\alpha$, onset of standing estrus occurred in 12 of 15 goats(80.0%) at 50.0$\pm$7.7h and in 11 of 15 goats(73.3%) at 135.6$\pm$10.1h in PMSG and group and P4＋PMSG group, respectively. The mean interval from PGF2$\alpha$ injection to first estrus was significantly(P<0.01) earlier in PMSG group than in P4＋PMSG group. This result indicate that the delayed infusion of P4 in P4＋PMSG group caused the later exhibition of their estrous behaviors. However, duration fo frist estrus(31.5$\pm$2.6h vs 26.2$\pm$2.3h), length of estrous cycle(14.1$\pm$3.3d vs 16.6$\pm$3.8d) and percentage of short estrous cycle(50.0% vs 45.5%) were not different between PMSG and P4＋PMSG group. The mean concentration of serum E2 in 4 goats showing normal estrous cycle in P4＋PMSG group(PP-NEC) was higher than in 6 goats showing normal(P-NEC) or in 6 goats showing short estrous cycle(P-SEC) in PMSG group. The peak level of serum E2 was observed at the time of onset of standing estrus in PP-NEC(67.6pg/ml), 6h earlier in P-NEC(53.1pg/ml) and 6h later in P-SEC(52.3pg/ml) than the onset of standing estrus. The profiles of serum concentration of E2 during the period of peri-estrus was similar in the goats of PMSG or P4＋PMSG and also in the goats showing the subsequent estrous cycle of normal or short length.

• Development and Reproduction
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• v.17 no.4
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• pp.441-449
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• 2013

Recent study showed that T cells in the immune organs and peripheral blood are influenced by estradiol, leading to a dysfunction of the immune system. However, little is known about the thymic-gonadal relationship during the estrous cycle in mouse. Therefore, the purpose of this study was to elucidate the mechanism by which a change in estradiol levels during the estrous cycle regulates the development of T cells in the mouse thymus. Six-week-old ICR mice were used and divided into four groups, including diestrous, proestrous, estrous, and metestrous. We first confirmed that ER-${\alpha}$ and - ${\beta}$ estrogen receptors were expressed in thymic epithelial cells, showing that their expression was not different during the estrous cycle. There was also no significant difference in thymic weight and total number of thymocytes during the estrous cycle. To determine the degree of thymocyte differentiation during the estrous cycle, we analyzed thymocytes by flow cytometry. As a result, the percentage of CD4+CD8+ double-positive (DP) T cells was significantly decreased in the proestrous phase compared to the diestrous phase. However, CD4+CD8- or CD4-CD8+ (SP) T cells were significantly increased in the proestrous phase compared to the diestrous phase. In addition, the percentage of CD44+CD25- (DN1) T cells was significantly decreased in the estrous phase compared to other phases, whereas the percentages of CD44+CD25+ (DN2), CD44-CD25+ (DN3), and CD44-CD25- (DN4) were not changed during the estrous cycle. These results indicate that the development of thymocytes may arrest in the DP to SP transition stage in the proestrous phase displaying the highest serum level of estradiol. This study suggests that a change in estradiol levels during the estrous cycle may be involved in the regulation of thymocyte differentiation in the mouse thymus.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.253-262
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• 1989

This study was performed to investigate the patterns of progesterone secretion after induction of estrus in premature, metestrous and anestrous bitches. A total of 22 bitches were used. Of them 18 bitches were treated with hormone to induced estrus and 4 bitches were untreated and served as controls. Estrus was induced with $PGF_{2{\alpha}}$, estrone, estradiol-$17{\beta}$, PMSG and HCG(Treatment A), and with PMSG and HCG(Treatment B). Blood samples were collected via the cephalic vein at 2 to 5 days interval. Blood samples were centrifuged (1,200g, 10min.) within 30 minutes after collection and plasma was stored at $-20^{\circ}C$ until analyzed for the progesterone concentrations. Plamsa progesterone concentrations were measured by radioimmunoassay. The results of estrous induction were determined by estrous signs, ovarian response, egg recovery and progesterone patterns. The results obtained were as follows; 1. All bitches in treatment A showed estrous signs, however the ovarian response and egg recovery were not detectable and the levels of progesterone were nearly same as before. 2. In the treatment B, premature and metestrous bitches showed only estrous signs, however 5 of 7 anestrous bitches (71.4%) showed estrous signs, ovarian response and changes of progesterone levels. In conclusion, clinical estrous behavior can be induced during any phase of the estrous cycle, but ovulation should be induced only if induction occur approximately 4 months or more after the previous estrus.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.398-402
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• 2007

Abstract Female mice post weaning were exposed to 20 kHz sawtooth electric and magnetic fields (EMF) with $6.25{\mu}T$ peak intensity for 6 weeks. Estrous cycles were checked using vaginal smears over the last 10 days of the experimental period. The vaginal smears from EMF-exposed mice revealed an increase in the frequency of one or two phases persisting. The number of estrous cycles less than 1 was more in the EMF-exposed group than in the sham control group. Furthermore, in the EMF-exposed group, the duration of proestrous and metestrous stages of the estrous cycle was significantly increased compared with the control group. In conclusion, our results suggest that exposure to 20 kHz sawtooth EMF may affect normal cycling of the estrous cycle by disrupting the female reproductive endocrine physiology. We should not disregard the possible adverse reproductive effect of the 20 kHz sawtooth EMF generated under the occupational exposure situation in females.

• Sleep Medicine and Psychophysiology
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• v.9 no.2
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• pp.81-85
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• 2002

There are several factors which are more likely to have sleep disorders in fertile women with menstruation than adult men. Menstrual cycle plays an important role in them. We describe herein the overview about the association of menstrual cycle and sleep disorders by viewing the interactions of menstrual cycle and circadian rhythm. We review how menstrual cycle affects sleep-wake cycle by reviewing menstrual cycle and estrous cycle to understand these interactions. Menstrual cycle and estrous cycle are mainly affected by hormonal cycle and light-dark cycle, respectively and they are generally determined in monthly rhythm and annual rhythm, respectively. The determination of estrous cycle is also affected by cyclic changes of hormones besides light-dark cycle. Although sleep-wake cycle almost alternates according to estrous cycle in non-primate mammals, it is hardly affected by menstrual cycle in primate mammals as compared with estrous cycle. But menstrual cycle affects sleep-wake cycle via desynchronization of sleep-wake cycle and temperature rhythm. The decrease of amplitude and phasic change during luteal phase in the daily fluctuation of body core temperature can partially contribute to the induction of sleep disorders in fertile women. In addition to this, premenstrual syndrome which nearly happens during luteal phase commonly have sleep problems. Therefore, we suggest that menstrual cycle and PMS can partially contribute the increase of sleep disorders in fertile women.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1411-1415
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• 2008

The purpose of the present study was to determine the onset of breeding season, the occurrence of silent and true heats and the duration of estrus in female Markhoz goats of the Kurdistan province in Iran. Ten, 3 years-old Markhoz does with an average weight of $34.05{\pm}2.62kg$ and with one kidding record, were used. The goats were maintained in an open barn under constant nutritional levels and natural photoperiod. One aproned buck was used twice a day every 12 h to detect estrus from mid August to early January. For the determination of the onset of reproductive activity as well as occurrence of silent heat, blood samples were collected every 10 days, from the beginning of the experiment. After $2^{nd}$ standing heat, blood samples were obtained twice a week in order to assess luteal activity and the length of estrous cycles. In this study, estrous behavior was observed including sniffing, vocal exchange, following courtship, flehman, standing heat and mounting. The results of the progesterone assay indicated that in this goat silent heats occur mostly in the early breeding season. The first standing heat was observed in mid-October which was considered as the onset of the breeding season. Duration of the estrous cycle and estrus was recorded as being $20.93{\pm}1.56days$ and $38.86{\pm}15.19h$, respectively. The correlation coefficient between length of daylight and occurrence of estrus was negative (r = -0.470) but not significant (p>0.05). The data showed that there was no significant effect of body weight on estrous cycles (first, second and third) and estrous periods (first, second, third and fourth). Progesterone levels were not significantly different in the first, second and third estrous cycles at days 0, 4, 10, 12, 14 and 19. The results of progesterone assay during the estrous cycle indicate that follicular and luteal phases last 4-5 and 14-15 days, respectively and the concentration of serum progesterone in these phases was $0.88{\pm}0.08$ and $7.44{\pm}0.26ng/ml$, respectively. The study concluded that Markhoz does could be considered as a breed with a short breeding season and an optimal estrous activity in autumn.