scholarly journals Immunotoxic Destruction of Distinct Catecholaminergic Neuron Populations Disrupts the Reproductive Response to Glucoprivation in Female Rats

Endocrinology ◽  
2003 ◽  
Vol 144 (10) ◽  
pp. 4325-4331 ◽  
Author(s):  
Helen I’Anson ◽  
Lois A. Sundling ◽  
Shannon M. Roland ◽  
Sue Ritter
Keyword(s):  
Cycle Length ◽  
Reproductive Function ◽  
Female Rats ◽  
Estrous Cycles ◽  
Neuron Populations ◽  
Reproductive Response ◽  
Estrous Cyclicity ◽  
Catecholaminergic Neuron ◽  
Catecholamine Neurons ◽  
Glucoprivic Feeding

We tested the hypothesis that hindbrain catecholamine (norepinephrine or epinephrine) neurons, in addition to their essential role in glucoprivic feeding, are responsible for suppressing estrous cycles during chronic glucoprivation. Normally cycling female rats were given bilateral injections of the retrogradely transported ribosomal toxin, saporin, conjugated to monoclonal dopamine β-hydroxylase antibody (DSAP) into the paraventricular nucleus (PVN) of the hypothalamus to selectively destroy norepinephrine and epinephrine neurons projecting to the PVN. Controls were injected with unconjugated saporin. After recovery, we assessed the lesion effects on estrous cyclicity under basal conditions and found that DSAP did not alter estrous cycle length. Subsequently, we examined effects of chronic 2-deoxy-d-glucose-induced glucoprivation on cycle length. After two normal 4- to 5-d cycles, rats were injected with 2-deoxy-d-glucose (200 mg/kg every 6 h for 72 h) beginning 24 h after detection of estrus. Chronic glucoprivation increased cycle length in seven of eight unconjugated saporin rats but in only one of eight DSAP rats. Immunohistochemical results confirmed loss of dopamine β-hydroxylase immunoreactivity in PVN. Thus, hindbrain catecholamine neurons with projections to the PVN are required for inhibition of reproductive function during chronic glucose deficit but are not required for normal estrous cyclicity when metabolic fuels are in abundance.

scholarly journals SUN-239 Effects of High-Fat Diet-Induced Obesity on Pulsatile LH Secretion and Hypothalamic KISS1 Expression in Female Rats

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Shiori Minabe ◽  
Kinuyo Iwata ◽  
Youki Watanabe ◽  
Hitoshi Ozawa
Keyword(s):  
Body Weight ◽  
High Fat Diet ◽  
Pulse Frequency ◽  
Female Rats ◽  
Standard Diet ◽  
High Fat ◽  
Estrous Cycles ◽  
Menstrual Dysfunction ◽  
Estrous Cyclicity ◽  
Lh Secretion

Abstract Female obesity is associated with menstrual dysfunction leading to anovulation and infertility. It has recently been reported obesity-induced infertility is involved in the dysfunction of a kisspeptin neuron, a key player in reproduction via direct stimulation of gonadotropin releasing hormone (GnRH) and subsequent gonadotropin release in mammalian species. Previous studies reported that obesity due to high-fat diet (HFD) for 8 months induced a disruption in estrous cyclicity, caused by a decrease in Kiss1 (coding kisspeptin) expression in the hypothalamic arcuate nucleus (ARC) in female rodents. Here we showed the effects of shorter-term (4 months) HFD on pulsatile LH secretion and hypothalamic Kiss1 expression to show pathogenic mechanism underlying obesity-induced infertility. Female Wistar-Imamichi strain rats (7 weeks old) fed on either a standard diet (10% calories from fat) or a high-fat diet (45% calories from fat) for 4 months. Estrous cyclicity and body weight were monitored regularly. All animals were implanted with a jugular catheter and collected blood samples to analyze pulsatile LH secretion, after a week of the ovariectomy with low-dose replacement estradiol to negate influence of changes in ovarian steroid levels and mimic diestrous levels of plasma estrogen. On the next day of the blood sampling, rats were perfused with 0.05 M PBS followed by 4% paraformaldehyde and their brains were collected for in situ hybridization of Kiss1 and Gnrh1. The HFD-fed rats showed progressive increases in body weight, along with hyperphagia and adipose tissue accumulation, compared with control animals. Fifty-eight percent of the HFD-fed rats exhibited irregular estrous cycles, whereas remaining HFD-fed rats showed regular cycles. Two out of 7 rats showing HFD-induced irregular estrous cycles exhibited profound suppression of the LH pulse frequency and the number of Kiss1-expressing cells in the ARC, whereas remaining HFD-fed rats showed normal LH pulses and ARC Kiss1 expressions. The number of Kiss1-expressing cells in the ARC had close positive correlation with LH pulse frequency (R2=0.6872, P<0.001) in both groups. Additionally, the number of Kiss1- or Gnrh1-expressing cells in the anteroventral periventricular nucleus or the preoptic area, were comparable between groups. Taken together, our finding reveals the possibility that irregular menstruation was also induced by changes in the kisspeptin-GnRH independent pathway during the incipient stage of obese infertility.

scholarly journals Relative Importance of the Arcuate and Anteroventral Periventricular Kisspeptin Neurons in Control of Puberty and Reproductive Function in Female Rats

Endocrinology ◽  
2015 ◽  
Vol 156 (7) ◽  
pp. 2619-2631 ◽  
Author(s):  
M. H. Hu ◽  
X. F. Li ◽  
B. McCausland ◽  
S. Y. Li ◽  
R. Gresham ◽  
...  
Keyword(s):  
Pubertal Timing ◽  
Critical Role ◽  
Reproductive Function ◽  
Pulse Frequency ◽  
Pulse Generation ◽  
Female Rats ◽  
Relative Importance ◽  
Lh Surge ◽  
Estrous Cyclicity

Kisspeptin plays a critical role in pubertal timing and reproductive function. In rodents, kisspeptin perikarya within the hypothalamic arcuate (ARC) and anteroventral periventricular (AVPV) nuclei are thought to be involved in LH pulse and surge generation, respectively. Using bilateral microinjections of recombinant adeno-associated virus encoding kisspeptin antisense into the ARC or AVPV of female rats at postnatal day 10, we investigated the relative importance of these two kisspeptin populations in the control of pubertal timing, estrous cyclicity, and LH surge and pulse generation. A 37% knockdown of kisspeptin in the AVPV resulted in a significant delay in vaginal opening and first vaginal estrous, abnormal estrous cyclicity, and reduction in the occurrence of spontaneous LH surges, although these retained normal amplitude. This AVPV knockdown had no effect on LH pulse frequency, measured after ovariectomy. A 32% reduction of kisspeptin in the ARC had no effect on the onset of puberty but resulted in abnormal estrous cyclicity and decreased LH pulse frequency. Additionally, the knockdown of kisspeptin in the ARC decreased the amplitude but not the incidence of LH surges. These results might suggest that the role of AVPV kisspeptin in the control of pubertal timing is particularly sensitive to perturbation. In accordance with our previous studies, ARC kisspeptin signaling was critical for normal pulsatile LH secretion in female rats. Despite the widely reported role of AVPV kisspeptin neurons in LH surge generation, this study suggests that both AVPV and ARC populations are essential for normal LH surges and estrous cyclicity.

Periodic, short-term heat exposure and reproductive function in male and female rats

1978 ◽  
Vol 56 (5) ◽  
pp. 747-753 ◽  
Author(s):  
Edwin A. Knecht ◽  
Gary L. Wright ◽  
Mark A. Toraason
Keyword(s):  
Heat Treatment ◽  
Heat Exposure ◽  
Reproductive Function ◽  
Female Rats ◽  
Short Term ◽  
Estrous Cycles ◽  
Male And Female ◽  
Fetal Survival ◽  
Male And Female Rats ◽  
High Incidence

Reproductive function of male and female rats was examined in relation to periodic, short-term heat treatment. Daily exposure to an environmental temperature of 38.2 °C for 55 min elevated rectal temperatures to 39.9 and 41.2 °C in male and female rats, respectively. Heat exposure tended to decrease copulation in males cohabitated with unhealed females. The rate of conception was affected similarly, and fetal survival tended to be reduced by paternal heat treatment. Estrous cycles were disrupted initially in heat-exposed females, but the rate of copulation and conception of females cohabitated with unheated males was unaltered by heat treatment. However, maternal heat exposure impaired prenatal survival and growth. During lactation, a high incidence of maternal and pup deaths was observed at approximately 14 days postpartum. Maternal deaths were coincident with a decrease in thermoregulatory ability and rectal temperatures exceeding 42 °C.

scholarly journals Ablation of KNDy Neurons Results in Hypogonadotropic Hypogonadism and Amplifies the Steroid-Induced LH Surge in Female Rats

Endocrinology ◽  
2016 ◽  
Vol 157 (5) ◽  
pp. 2015-2027 ◽  
Author(s):  
Melinda A. Mittelman-Smith ◽  
Sally J. Krajewski-Hall ◽  
Nathaniel T. McMullen ◽  
Naomi E. Rance
Keyword(s):  
Arcuate Nucleus ◽  
Hypogonadotropic Hypogonadism ◽  
Reproductive Function ◽  
Female Rats ◽  
Lh Surge ◽  
Serum Lh ◽  
Estrous Cyclicity ◽  
17Β Estradiol ◽  
Neurokinin 3 Receptor ◽  
Kndy Neurons

Abstract In the human infundibular (arcuate) nucleus, a subpopulation of neurons coexpress kisspeptin and neurokinin B (NKB), 2 peptides required for normal reproductive function. A homologous group of neurons exists in the arcuate nucleus of rodents, termed KNDy neurons based on the coexpression of kisspeptin, NKB, and dynorphin. To study their function, we recently developed a method to selectively ablate KNDy neurons using NK3-SAP, a neurokinin 3 receptor agonist conjugated to saporin (SAP). Here, we ablated KNDy neurons in female rats to determine whether these neurons are required for estrous cyclicity and the steroid induced LH surge. NK3-SAP or Blank-SAP (control) was microinjected into the arcuate nucleus using stereotaxic surgery. After monitoring vaginal smears for 3–4 weeks, rats were ovariectomized and given 17β-estradiol and progesterone in a regimen that induced an afternoon LH surge. Rats were killed at the time of peak LH levels, and brains were harvested for NKB and dual labeled GnRH/Fos immunohistochemistry. In ovary-intact rats, ablation of KNDy neurons resulted in hypogonadotropic hypogonadism, characterized by low levels of serum LH, constant diestrus, ovarian atrophy with increased follicular atresia, and uterine atrophy. Surprisingly, the 17β-estradiol and progesterone-induced LH surge was 3 times higher in KNDy-ablated rats. Despite the marked increase in the magnitude of the LH surge, the number of GnRH or anterior ventral periventricular nucleus neurons expressing Fos was not significantly different between groups. Our studies show that KNDy neurons are essential for tonic levels of serum LH and estrous cyclicity and may play a role in limiting the magnitude of the LH surge.

scholarly journals Neonatal handling and reproductive function in female rats

2005 ◽  
Vol 184 (2) ◽  
pp. 435-445 ◽  
Author(s):  
C M Gomes ◽  
C Raineki ◽  
P Ramos de Paula ◽  
G S Severino ◽  
C V V Helena ◽  
...  
Keyword(s):  
Estrous Cycle ◽  
Plasma Levels ◽  
Preoptic Area ◽  
Reproductive Function ◽  
Female Rats ◽  
Estrous Cycles ◽  
Neonatal Handling ◽  
Environmental Stimulation ◽  
Medial Septal Area ◽  
Lh Releasing Hormone

Neonatal handling induces anovulatory estrous cycles and decreases sexual receptivity in female rats. The synchronous secretion of hormones from the gonads (estradiol (E2) and progesterone (P)), pituitary (luteinizing (LH) and follicle-stimulating (FSH) hormones) and hypothalamus (LH-releasing hormone (LHRH)) are essential for the reproductive functions in female rats. The present study aimed to describe the plasma levels of E2 and P throughout the estrous cycle and LH, FSH and prolactin (PRL) in the afternoon of the proestrus, and the LHRH content in the medial preoptic area (MPOA), median eminence (ME) and medial septal area (MSA) in the proestrus, in the neonatal handled rats. Wistar pup rats were handled for 1 min during the first 10 days after delivery (neonatal handled group) or left undisturbed (nonhandled group). When they reached adulthood, blood samples were collected through a jugular cannula and the MPOA, ME and MSA were microdissected. Plasma levels of the hormones and the content of LHRH were determined by RIA. The number of oocytes counted in the morning of the estrus day in the handled rats was significantly lower than in the nonhandled ones. Neonatal handling reduces E2 levels only on the proestrus day while P levels decreased in metestrus and estrus. Handled females also showed reduced plasma levels of LH, FSH and PRL in the afternoon of the proestrus. The LHRH content in the MPOA was significantly higher than in the nonhandled group. The reduced secretion of E2, LH, FSH and LHRH on the proestrus day may explain the anovulatory estrous cycle in neonatal handled rats. The reduced secretion of PRL in the proestrus may be related to the decreased sexual receptiveness in handled females. In conclusion, early-life environmental stimulation can induce long-lasting effects on the hypothalamus-pituitary-gonad axis.

scholarly journals Impact of Circadian Disruption on Female Mice Reproductive Function

Endocrinology ◽  
2020 ◽  
Vol 161 (4) ◽  
Author(s):  
Thibault Bahougne ◽  
Mathilda Kretz ◽  
Eleni Angelopoulou ◽  
Nathalie Jeandidier ◽  
Valérie Simonneaux
Keyword(s):  
Biological Clock ◽  
Reproductive Function ◽  
Reproductive Activity ◽  
Women Studies ◽  
Estrous Cycles ◽  
Lh Surge ◽  
Positive Feedbacks ◽  
Female Mice ◽  
Reproductive Effects ◽  
Estrous Cyclicity

Abstract In female mammals, cycles in reproductive function depend both on the biological clock synchronized to the light/dark cycle and on a balance between the negative and positive feedbacks of estradiol, whose concentration varies during oocyte maturation. In women, studies report that chronodisruptive environments such as shiftwork may impair fertility and gestational success. The objective of this study was to explore the effects of shifted light/dark cycles on both the robustness of the estrous cycles and the timing of the preovulatory luteinizing hormone (LH) surge in female mice. When mice were exposed to a single 10-hour phase advance or 10-hour phase delay, the occurrence and timing of the LH surge and estrous cyclicity were recovered at the third estrous cycle. By contrast, when mice were exposed to chronic shifts (successive rotations of 10-hoursour phase advances for 3 days followed by 10-hour phase delays for 4 days), they exhibited a severely impaired reproductive activity. Most mice had no preovulatory LH surge at the beginning of the chronic shifts. Furthermore, the gestational success of mice exposed to chronic shifts was reduced, because the number of pups was 2 times lower in shifted than in control mice. In conclusion, this study reports that exposure of female mice to a single phase shift has minor reproductive effects, whereas exposure to chronically disrupted light/dark cycles markedly impairs the occurrence of the preovulatory LH surge, leading to reduced fertility.

Effect of Exposure to Mixture of Heavy Metals Arsenic, Cadmium and Lead on Reproductive Function and Oxidative Stress in Female Rats

2017 ◽  
Vol 9 (03) ◽  
Author(s):  
Choudhuri D. ◽  
Bhattacharjee T.
Keyword(s):  
Oxidative Stress ◽  
Heavy Metals ◽  
Ascorbic Acid ◽  
Reproductive Function ◽  
Reproductive Organs ◽  
Female Rats ◽  
Corpora Lutea ◽  
Oestrus Cycle ◽  
Implantation Sites ◽  
Live Fetus

Background : Toxicological consequences arising from exposure to mixtures of heavy metals especially at low, chronic and environmentally relevant doses are poorly recognised. In the present study, we evaluated effects of chronic exposure to combinations of three metals arsenic (As), cadmium (Cd) and lead (Pb) present frequently in drinking water on reproductive function and oxidative damage caused to reproductive organs of female rats. Method : Female rats were exposed to mixture of metals (As, Cdand Pb) for 90 consecutive days. The gain in body weight and weight of reproductive organs were recorded following autopsy on 91 stday. The oestrus cycle were monitored during entire treatment period. Numbers of corpora lutea, implantation sites, live fetus and survival of the fetus were evaluated in rats mated successfully with untreated male after completion of their respective treatment. Ovarian cholesterol, protein, ascorbic acid and enzyme Δ 5 -3β HSD levels were estimated. Serum levels of steroid hormones oestrogen and progesterone were estimated. Histopathological picture of both ovary and uterus were assessed. Levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidise (GPX) activity, amount of reduced glutathione (GSH) and malondyaldehyde (MDA) in blood, ovary and uterus were measured as biomarkers of oxidative stress. Results : The treated rats showed reduced body weight gain and reduction in the weight of ovary and uterus. Oestrus cycle was disrupted with continuous diestrous in treated animals. Number of corpora lutea, implantation sites and live fetus and the survival of fetus evaluate were reduced significantly in treated groups. The levels of ovarian cholesterol and ascorbic acid increased in treated rats with decrease Δ5 -3β HSD level. There was reduction in serum level of both the ovarian steroid hormones oestrogen and progesterone. The protein levels did not differ between the groups. There was a significant increase in levels of MDA and decrease in levels of all the antioxidant enzymes in treated group. Conclusion : The results revealed there was disruption to reproductive functions with decrease in stereoidogenic activity and associated oxidative stress in female rats treated with combination of mixture of metals (Cd, As and Pb) at low dose for 90 consecutive days.

Assessment of Superoxide Dismutase and Catalase Evolution in Different Stages of an Experimental Endometriosis

2017 ◽  
Vol 68 (6) ◽  
pp. 1381-1383
Author(s):  
Allia Sindilar ◽  
Carmen Lacramioara Zamfir ◽  
Eusebiu Viorel Sindilar ◽  
Alin Constantin Pinzariu ◽  
Eduard Crauciuc ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
Reproductive Function ◽  
Female Rats ◽  
Oxygen Species ◽  
Efficient Treatment ◽  
Endometrial Cells ◽  
Gynecological Disorder ◽  
The Impact

Endometriosis is described as a gynecological disorder characterized by the presence of endometrial tissue outside the uterus; extensively explored because of its increasing incidency, with an indubitable diagnostic only after invasive surgery, with no efficient treatment, it has still many aspects to be elucidated. A growing body of facts sustain oxidative stress as a crucial factor between the numerous incriminated factors implicated in endometriosis ethiopathogeny. Reactive oxygen species(ROS) act to decline reproductive function. Our study intends to determine if an experimental model of endometriosis may be useful to assess the impact of oxidative stress on endometrial cells; we have used a murine model of 18 adult Wistar female rats. A fragment from their left uterine horn was implanted in the abdominal wall. After 4 weeks, a laparatomy was performed, 5 endometrial implants were removed, followed by biochemical tissue assay of superoxide dismutase(SOD) and catalase(CAT). At the end of the experiment, the rats were sacrificed, the implants were removed for histopathological exam and biochemical assay of antioxidant enzymes. The results revealed decreased levels of antioxidant enzymes, pointing on significant oxidative stress involvement.

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