scholarly journals Determination of the estrous cycle phases of rats: some helpful considerations

2002 ◽  
Vol 62 (4a) ◽  
pp. 609-614 ◽  
Author(s):  
F. K. MARCONDES ◽  
F. J. BIANCHI ◽  
A. P. TANNO
Keyword(s):  
Estrous Cycle ◽  
Cell Types ◽  
Short Length ◽  
Female Rats ◽  
Cycle Phase ◽  
Objective Lens ◽  
Vaginal Smear ◽  
Vaginal Secretion ◽  
Cellular Types

The short length of the estrous cycle of rats makes them ideal for investigation of changes occurring during the reproductive cycle. The estrous cycle lasts four days and is characterized as: proestrus, estrus, metestrus and diestrus, which may be determined according to the cell types observed in the vaginal smear. Since the collection of vaginal secretion and the use of stained material generally takes some time, the aim of the present work was to provide researchers with some helpful considerations about the determination of the rat estrous cycle phases in a fast and practical way. Vaginal secretion of thirty female rats was collected every morning during a month and unstained native material was observed using the microscope without the aid of the condenser lens. Using the 10 x objective lens, it was easier to analyze the proportion among the three cellular types, which are present in the vaginal smear. Using the 40 x objective lens, it is easier to recognize each one of these cellular types. The collection of vaginal lavage from the animals, the observation of the material, in the microscope, and the determination of the estrous cycle phase of all the thirty female rats took 15-20 minutes.

Pharmacological evidence for β2-adrenoceptor in right atria from stressed female rats

1999 ◽  
Vol 77 (6) ◽  
pp. 432-440 ◽  
Author(s):  
R C Spadari-Bratfisch ◽  
I N Santos ◽  
LCM Vanderlei ◽  
F K Marcondes
Keyword(s):  
Estrous Cycle ◽  
Model Equation ◽  
Female Rats ◽  
Cycle Phase ◽  
Response Curves ◽  
Chronotropic Response ◽  
Site Model ◽  
Stressed Female ◽  
Right Atria ◽  
Shock Stress

The purpose of the present study was to demonstrate a physiological response to TA2005, a potent β2-adrenoceptor (β2-AR) selective agonist, in right atria isolated from stressed female rats under the influence of the estrous cycle. We obtained concentration-response curves to the agonist in the presence and in the absence of selective antagonists in right atria isolated from female rats submitted to three daily foot-shock sessions (30 min duration, 120 pulses of 1.0 mA, 1.0 s, applied at random intervals of 5-25 s) and sacrificed at estrus or diestrus. Our results showed that the pD2 values of TA2005 were not influenced by estrous cycle phase or foot-shock stress. However, in right atria from stressed rats sacrificed during diestrus, the concentration-response curve to TA2005 was biphasic, with a response being obtained at concentrations of 0.1 nM, whereas during estrus no response was observed at doses lower than 3 nM. ICI118,551, a β2-AR antagonist, abolished the response to nanomolar concentrations of TA2005 in right atria from stressed rats at diestrus, with no changes in agonist pD2 values in right atria from control rats (7.47 ± 0.09, p > 0.05) but a 3-fold decrease in pD2 values of TA2005 in right atria from foot shock stressed rats (7.90 ± 0.07, p [Formula: see text] 0.05). Concentration-response curves to TA2005 in the presence of ICI118,551 were best fitted by a one-site model equation. The β1-AR antagonist, CGP20712A, shifted to the right only the second part of the concentration-response curves to the agonist, unmasking the putative β2-AR-mediated response to the agonist in tissues isolated from stressed rats at diestrus. Under this condition, concentration-response curves to the agonist were best fitted by a two-site model equation. pD2 and maximum response of TA2005 interaction with β1- and putative β2-adrenoceptor components were calculated. Schild analyses gave a pKB value for CGP20712A that was typical for the interaction with β1-AR in each experimental group. pKB values for ICI118,551 could not be obtained in stressed rats sacrificed at diestrus since Schild plot slopes were lower than 1.0. In right atria from control rats, ICI118,551 pKB values were similar to reported values for the interaction of the antagonist with β1-AR. These results confirm that a heterogenous β-AR population mediating the chronotropic response to catecholamines can be demonstrated in right atria from foot shock stressed female rats sacrificed at diestrus. The stress-induced response seems to be mediated by the β2-AR subtype. Right atria from rats sacrificed during estrus are protected against stress-induced alterations on the homogeneity of β-AR population.Key words: foot-shock stress, TA2005, ICI118,551, CGP20712A, estrus, diestrus.

scholarly journals Disruption of Ovarian Utilisation of Proteins by Tetrapleuratetraptera Fruit Extract Impairs Estrous Cycle and Ovarian Functions in Female Rats

2021 ◽  
pp. 1-8
Author(s):  
Ologhaguo Macstephen Adienbo ◽  
Ogechi Stephanie Ezeala
Keyword(s):  
Superoxide Dismutase ◽  
Body Weight ◽  
Estrous Cycle ◽  
Cycle Length ◽  
Female Rats ◽  
Total Protein Content ◽  
Vaginal Smear ◽  
Fruit Extract ◽  
Sod Activity ◽  
Microscopic Evaluation

Aim: Reports that some phytochemicals interfere with reproductive functions, in both humans and animals necessitated this study which is aimed at determining the effects of fruit extract of Tetrapleuratetrapteraon oestrous cycle and ovarian functions in females. Methods: Adult female wistar rats weighing 160-180 g with regular 4-5 days oestrus cycle were selected into 4 groups of 6 animals each. Group 1 (control) administered 1ml distilled water; groups II, III and IV were daily treated with the extract at doses 75 mg/kg, 150mg/kg and 300 mg/kg body weight respectively, orally for 21 days. Microscopic evaluation of vaginal smear was done daily to determine the various stages of the estrous cycle, their duration, as well as the estrous cycle length. After 24 hours of last administration, each rat was weighed, sacrificed, and right ovary was homogenised and the homogenate used for analyses of total protein content, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) concentration, according to standard protocols. Results: There was significant (P < 0.05) increase in duration of diestrus phase and estrous cycle length in all the extract-treated groups, compared to control animals. Also, there was relative reductions in the duration for proestrus (p<0.05), estrus (p<0.05) and metestrus (p<0) phases of the cycle, with a relative increase in duration for diestrus phase (p<0.05) in animals treated with 150 mg/kg and 300 mg/kg body weight respectively. In addition, a significant (P < 0.05) increase was observed in ovarian Protein, and Superoxide dismutase (SOD) enzyme activity; as well as significant (P < 0.05) reduction in malondialdehyde (MDA) level and in weight gain in the test animals, compared to the control. Conclusion:Tetrapleuratetrapterafruit extract disrupts ovarian utilisation of proteins in the ovaries, thereby impairing oestrous cyclicity, and body weight. These could result to infertility.

scholarly journals Estrous influence on surgical cure of a mouse breast cancer.

1988 ◽  
Vol 168 (1) ◽  
pp. 73-83 ◽  
Author(s):  
H V Ratajczak ◽  
R B Sothern ◽  
W J Hrushesky
Keyword(s):  
Breast Cancer ◽  
Estrous Cycle ◽  
Tumor Resection ◽  
Metastatic Potential ◽  
Cell Types ◽  
High Amplitude ◽  
Mammary Adenocarcinoma ◽  
Vaginal Smear ◽  
Surgical Removal ◽  
Small Range

We have studied the effect of estrous stage, as reflected by vaginal cellularity, at the time of surgical resection of an estrogen receptor-bearing mammary adenocarcinoma upon the metastatic potential of that tumor in the C3HeB/FeJ mouse. Presence of the tumor prolonged the length of the estrous cycle by approximately 25% and removal of the tumor returned the cycle to its usual duration. Neither estrous stage at tumor implant nor size of tumor at resection (within a small range) had significant independent effects upon differences observed in the incidence of subsequent pulmonary metastases. However, estrous stage at time of surgical removal of the tumor, as reflected by cell types in vaginal smear, markedly affected whether or not metastases ultimately appeared. Because the estrous cycle in mice, comparable to the human menstrual cycle, reflects high-amplitude, rhythmic changes in hormone concentrations, it may be that the hormonal status of a women at the time of tumor resection is an important determinant of whether or not that breast cancer ultimately metastasizes.

Correlation of Vaginal Smears and Surface Structure in the Normal Estrous Cycle of Rats

1985 ◽  
Vol 43 ◽  
pp. 654-655
Author(s):  
Kaufmann Robert C. ◽  
Khosho Francis K. ◽  
Amankwah Kofi S.
Keyword(s):  
Surface Structure ◽  
Estrous Cycle ◽  
Adult Female ◽  
Female Rats ◽  
Vaginal Smear ◽  
Vaginal Smears ◽  
Ultrastructural Studies ◽  
Ultrastructural Findings

Few studies regarding the normal estrous cycle of rats exist in the literature. Only the estrous and diestrous portions of the cycle have been studied in any detail in the spontaneous cycle of the rat. Ultrastructural studies of proestrous have been limited to artificially induced cycles. These artificially induced cycles have been unable to account for all the findings on vaginal smears seen in spontaneous cycles. In this study, vaginal smear findings were correlated to surface ultrastructural findings in the four main phases of spontaneous ovulatory cycles in rats.Adult female rats of the Sprague-Dawely strain were used and sacrificed during different phases of their cycles. Daily vaginal smears (8-11 a.m.) of at least two consecutive cycles were used to determine the phase of the normal estrous cycle for each rat.

Sexual dimorphism of the intracellular heat shock protein 72 response

2006 ◽  
Vol 101 (2) ◽  
pp. 566-575 ◽  
Author(s):  
M. Nickerson ◽  
S. L. Kennedy ◽  
J. D. Johnson ◽  
M. Fleshner
Keyword(s):  
Sexual Dimorphism ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Estrous Cycle ◽  
Stress Responses ◽  
Female Rats ◽  
Vaginal Smear ◽  
Mesenteric Lymph Nodes ◽  
Males And Females ◽  
The Impact

The majority of previous work examining stress responses has been done in males. Recently, it has become clear that the impact of stressor exposure is modulated by sex. One stress response that may be affected by sex is the induction of intracellular heat shock protein (HSP) 72, which is a stress- responsive molecular chaperone that refolds denatured proteins and promotes cellular survival. The following study compared HSP72 in males and females and also examined whether the estrous cycle altered HSP72 induction in females. We hypothesized that females compared with males would have a constrained HSP72 response after an acute stressor and that the stress-induced HSP72 response in females would fluctuate with the estrous cycle. Male and female F344 rats were either left in their home cage or exposed to acute tail-shock stress (8–10/group). Immediately following stressor, trunk blood was collected and tissues were flash frozen. Vaginal smear and estrogen enzyme immunoassay were used to categorize the phase of estrous. Results show that female rats had a greater corticosterone response than males, that both males and females exhibit a stress-induced release of progesterone, and that males and females had equal levels of stress-induced circulating norepinephrine. Sexual dimorphism of the HSP72 (ELISA) response existed in pituitary gland, mesenteric lymph nodes, and liver such that female rats had an attenuated HSP72 response compared with males after stress. The adrenal glands, spleen, and heart did not exhibit sexual dimorphism of the HSP72 response. The estrous cycle did not have a significant effect on basal or stress-induced HSP72 in females.

scholarly journals The leaf aqueous extract of Myrianthus arboreus P. Beauv. (Cecropiaceae) improved letrozole-induced polycystic ovarian syndrome associated conditions and infertility in female Wistar rats

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Marie Alfrede Mvondo ◽  
Flavie Ingrid Mzemdem Tsoplfack ◽  
Charline Florence Awounfack ◽  
Dieudonné Njamen
Keyword(s):  
Estrous Cycle ◽  
Aqueous Extract ◽  
Wistar Rats ◽  
Serum Levels ◽  
Female Infertility ◽  
Female Rats ◽  
Vaginal Smear ◽  
Promising Alternative ◽  
Fertility Index ◽  
Female Wistar Rats

Abstract Background Myrianthus arboreus P. Beauv. (Cecropiaceae) is a medicinal plant used to treat female infertility. The aqueous extract of M. arboreus leaves was found to improve the fertility of healthy female Wistar rats. In the present study, we proposed evaluating the effects of such an extract on an animal model of infertility caused by polycystic ovary syndrome (PCOS), in order to bring scientific evidence to the curative action of this plant against female infertility. Methods Following a 21-day administration (gavage) of letrozole (1 mg/kg), animals with PCOS, indicated by overweight and an estrous cycle blocked in the diestrus phase, were co-treated with letrozole (1 mg/kg) and the aqueous extract of M. arboreus leaves at doses of 20, 110 and 200 mg/kg. The positive control received clomiphene citrate (1 mg/kg) and metformin (200 mg/kg). The negative control received distilled water. Each group of animals was made up of 10 female rats. Vaginal smear was examined 7 days before and during co-treatments. Co-treatments were orally administered for 30 consecutive days and 5 animals per group were sacrificed thereafter for biochemical and histological analyses. The 5 remaining animals in each group were crossbred with males of proven fertility for 5 consecutive days. The daily examination of vaginal smears allowed evaluating fertility index. Following parturition, gestation rate was calculated. Results The aqueous extract of M. arboreus leaves reversed letrozole effects by decreasing body weight, abdominal fat accumulation, and serum levels of LH and testosterone (p < 0.001). Ovarian dynamic was improved and the number of tertiary, Graafian follicles (p < 0.001) and corpus luteum increased while that of cystic (p < 0.001) and atretic follicles (p < 0.01) decreased. These effects were associated with increased serum levels of estradiol, decreased ovarian oxidative stress, the resumption of the estrous cycle, the hypertrophy of uterine epithelial cells and increased fertility index and gestation rate. Conclusions These results justify at least in part, the traditional use of M. arboreus against female infertility and suggest that this plant could be a promising alternative treatment to improve symptoms associated with different PCOS phenotypes.

scholarly journals The Study of Estrous Cycle Phases Female Rats With the Use of N-Acetylcysteine in Ovarian Graft

2021 ◽  
Vol 23 (1) ◽  
pp. 47-50
Author(s):  
Maria Clara da Silva Durando Vieira ◽  
Elivânia de Amorim Marques Gomes ◽  
Edna Frasson de Souza Montero
Keyword(s):  
Estrous Cycle ◽  
Lethal Dose ◽  
Female Rats ◽  
Vaginal Smear ◽  
Regular Cycle ◽  
Ovarian Graft ◽  
Definition Of ◽  
Sanitary Conditions ◽  
Later Phase ◽  
Estrus Phase

AbstractOvarian graft may be the target of the biochemical effects of oxidative stress caused at the time of transplantation. In order to evaluate the effect of N-acetylcysteine on the ovarian graft, regarding the estrous cycle preservation , 50 female and virgin EPM-1 Wistar rats, weighing up to 250g, originating from CEDEME of UNIFESP, were kept in adequate sanitary conditions. , receiving their own food and water. Daily vaginal smears were performed to identify the estrous phase for 8 days. The animals were randomly distributed into 05 groups: 1st Group (GTx), saline was administered subcutaneously, 2nd (NAC 150mgKg), 3rd (NAC 300mg / Kg), 4th (NAC 600mg / Kg) and 5th (NAC 1200mg / Kg) , that were administered NAC subcutaneously on the abdominal face, 60 minutes before left unilateral ovarian transplantation in retroperitoneum and contralateral oophorectomy for purposes of histomorphological analysis, with colpocytological evaluation. Euthanasia was performed by means of anesthetic lethal dose in half of the animals on the 4th postoperative day, with a single vaginal smear collection and euthanasia on the rest of the animals, between the 14th and 16th days, after the material was collected in order to define the estrus phase. It was evaluated in the graft that the animals exhibited in all groups return of estrous cycle in the later phase of the post-transplant, with better definition of regular cycle in the highest dosages of N-acetylcysteine. N-acetylcysteine induced the return of the estrous cycle in the rats’ ovarian graft , mainly in the highest dosage, proving its effectiveness in revascularization of the tissue after ischemia and reperfusion. Keywords: Acetylcysteine. Reperfusion. Histocompatibility Antigens. Menstrual Cycle. ResumoO enxerto ovariano pode ser alvo dos efeitos bioquímicos do stress oxidativo causado no momento do transplante. Com o objetivo de avaliar o efeito da N-acetilcisteína no enxerto ovariano, quanto à preservação do ciclo estral, foram utilizados 50 ratos EPM-1 Wistar, fêmeas e virgens, pesando até 250g, originários do CEDEME da UNIFESP, mantidos em adequadas condições sanitárias, recebendo ração própria e água. Realizados esfregaços vaginais diários para identificação da fase estral durante 08 dias. Os animais foram distribuídos aleatoriamente em 05 grupos: 1º Grupo (GTx), administrada solução salina via subcutânea, 2º (NAC 150mgKg), 3º (NAC 300mg/Kg), 4º (NAC 600mg/Kg) e 5º (NAC 1200mg/Kg), aos quais foi administrada NAC por via subcutânea em face abdominal, 60 minutos antes do transplante unilateral esquerdo do ovário em retroperitônio e à ooforectomia contra-lateral para fins de análise histomorfológica, com avaliação colpocitológica. A eutanásia foi realizada por meio da dose letal do anestésico em metade dos animais no 4º dia de pós-operatório, realizado única coleta de esfregaço vaginal e a eutanásia no restante dos animais, entre o 14 º e 16º dia, após a coleta do material para definição da fase estro. Foi avaliado no enxerto que os animais apresentaram em todos os grupos retorno de ciclo estral na fase mais tardia do pós-transplante, com melhor definição de ciclo regular nas dosagens mais elevadas de N-acetilcisteína. A N-acetilcisteína induziu o retorno do ciclo estral no enxerto ovariano de ratas, principalmente na maior dosagem comprovando sua eficácia na revascularização do tecido após isquemia e reperfusão. Palavras-chave: Acetilcisteína. Reperfusão. Transplante. Ciclo Ovariano.

The β-adrenoceptor site activated by CGP12177 varies in behavior according to the estrous cycle phase and stress

2003 ◽  
Vol 81 (5) ◽  
pp. 459-468 ◽  
Author(s):  
I N Santos ◽  
F K Marcondes ◽  
R C Spadari-Bratfisch
Keyword(s):  
Estrous Cycle ◽  
Stress Hormones ◽  
Serum Levels ◽  
Female Rats ◽  
Cycle Phase ◽  
Response Curves ◽  
Chronotropic Response ◽  
The Right ◽  
Right Atria ◽  
Group Serum

The aim of this work was to assess whether stress and estrous cycle phases affected the β-adrenoceptor (β-AR) site activated by CGP12177 in the right atria of rats. The chronotropic response to CGP12177 in the absence or presence of antagonists was determined in atria from rats submitted to one daily foot-shock session for 3 consecutive days. Blood was collected for hormonal assays. The pD2 for CGP12177 in atria from females was lower than in atria from males and was unaltered by stress or the estrous cycle. Propranolol (200 nM) or CGP20712A (3 μM) shifted the concentration–response curves to CGP12177 to the right in control and stressed estrus or control diestrus rats. Atria from stressed diestrus rats were resistant to blockade by propranolol or CGP20712A, indicating that the effect of β-adrenoceptor antagonists on the response to CGP12177 is influenced by estrous cycle phases. The stress-induced increase in serum corticosterone levels was independent of the estrous cycle or gender, but the estradiol/progesterone ratio was affected differently in the two groups of female rats. In the diestrus group, serum estradiol levels decreased after the first foot-shock session and remained low until the day of sacrifice, whereas in the estrus group the serum levels of estradiol did not decrease after stress and peaked on the second day, which corresponded to proestrus. These data do not indicate whether there is a direct or indirect effect of stress hormones and (or) sex steroids on cardiac β-AR sensitivity. However, they do show that the classic and low-affinity binding sites of the β-AR are independently regulated and that the β-AR atypical site affinity for antagonists depends on the estrous cycle.Key words: allosterism, β-adrenoceptor, β-adrenoceptor, receptor active site, steroid hormones, stress.

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