scholarly journals Locus Coeruleus Mediates Cold Stress-Induced Polycystic Ovary in Rats

Endocrinology ◽  
2008 ◽  
Vol 149 (6) ◽  
pp. 2907-2916 ◽  
Author(s):  
Marcelo P. Bernuci ◽  
Raphael E. Szawka ◽  
Cleyde V. V. Helena ◽  
Cristiane M. Leite ◽  
Hernán E. Lara ◽  
...  

Previous reports about the rat ovary have shown that cold stress promotes ovarian morphological alterations related to a polycystic ovary (PCO) condition through activation of the ovarian sympathetic nerves. Because the noradrenergic nucleus locus coeruleus (LC) is activated by cold stress and synaptically connected to the preganglionic cell bodies of the ovarian sympathetic pathway, this study aimed to evaluate the LC’s role in cold stress-induced PCO in rats. Ovarian morphology and endocrine and sympathetic functions were evaluated after 8 wk of chronic intermittent cold stress (4 C, 3 h/d) in rats with or without LC lesion. The effect of acute and chronic cold stress upon the LC neuron activity was confirmed by Fos protein expression in tyrosine hydroxylase-immunoreactive neurons. Cold stress induced the formation of follicular cysts, type III follicles, and follicles with hyperthecosis alongside increased plasma estradiol and testosterone levels, irregular estrous cyclicity, and reduced ovulation. Considering estradiol release in vitro, cold stress potentiated the ovarian response to human chorionic gonadotropin. Ovarian norepinephrine (NE) was not altered after 8 wk of stress. However, LC lesion reduced NE activity in the ovary of cold-stressed rats, but not in controls, and prevented all the cold stress effects evaluated. Cold stress increased the number of Fos/tyrosine hydroxylase-immunoreactive neurons in the LC, but this effect was more pronounced for acute stress as compared with chronic stress. These results show that cold stress promotes PCO in rats, which apparently depends on ovarian NE activity that, under this condition, is regulated by the noradrenergic nucleus LC.

2019 ◽  
Vol 242 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Raul Riquelme ◽  
Freddy Ruz ◽  
Artur Mayerhofer ◽  
Hernán E Lara

An increase in the sympathetic tone in the rat ovary induces a polycystic ovary (PCOS-like) phenotype. No information exists about its impact on fertility. In contrast, increased follicular development and improved fertility in rats were found after pharmacological inhibition of acetylcholinesterase, which increased intraovarian acetylcholine (ACh). Now, we studied the impact of sympathetic stress, followed by a recovery period without stress, on the cholinergic and noradrenergic systems of the rat ovary and on fertility. To activate ovarian sympathetic nerves, female Sprague–Dawley rats were exposed to cold stress (4°C/3 h day for 28 days; first period), followed by a 28-day period without cold stress (second period). No changes in estrous cyclicity during the first period was found. At the end of this period, ovarian levels of NA and ACh were increased. Morphometric analysis showed lower numbers of secondary and antral follicles, enhanced follicular atresia and fewer corpora lutea. Plasma progesterone was lower and testosterone was higher than that in controls. At end of the second period, ovarian ACh levels had returned to control levels, but NA levels remained elevated. The second period was also characterized by the presence of cystic follicles in the ovary, by elevated plasma testosterone and estradiol levels, while progesterone levels were decreased. Estrous cyclicity and ovulation during that period were irregular and fertility decreased. Thus, cold stress initially activated both ovarian noradrenergic and cholinergic system. After stress, the ovary did not fully recover and activation of the noradrenergic system persisted and correlated with cystic ovarian morphology and decreased fertility.


2018 ◽  
Vol 239 (1) ◽  
pp. 81-91 ◽  
Author(s):  
V Squicciarini ◽  
R Riquelme ◽  
K Wilsterman ◽  
G E Bentley ◽  
H E Lara

RFamide-related peptide (RFRP-3) is a regulator of GnRH secretion from the brain, but it can also act in human ovary to influence steroidogenesis. We aimed to study the putative local role of RFRP-3 in the ovary and its potential participation in the development of a polycystic ovary phenotype induced by chronic sympathetic stress (cold stress). We used adult Sprague–Dawley rats divided into control and stressed groups. In both groups, we studied the effect of intraovarian exposure to RFRP-3 on follicular development and plasma ovarian steroid concentrations. We also tested the effect of RFRP-3 on ovarian steroid production in vitro. Chronic in vivo intraovarian exposure to RFRP-3 decreased basal testosterone concentrations and cold stress-induced progesterone production by the ovary. In vitro, RFRP-3 decreased hCG-induced ovarian progesterone and testosterone secretion. Immunohistochemistry and mRNA expression analysis showed a decrease in Rfrp and expression of its receptor in the ovary of stressed rats, a result which is in line with the increased testosterone levels found in stressed rats. In vivo application of RFRP-3 recovered the low levels of secondary and healthy antral follicles found in stressed rats. Taken together, our data indicate a previously unknown response of hypothalamic and ovarian RFRP-3 to chronic cold stress, influencing ovarian steroidogenesis and follicular dynamics. Thus, it is likely that RFRP-3 modulation in the ovary is a key component of development of the polycystic ovary phenotype.


Reproduction ◽  
2014 ◽  
Vol 148 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Rafael Barra ◽  
Gonzalo Cruz ◽  
Artur Mayerhofer ◽  
Alfonso Paredes ◽  
Hernán E Lara

Chronic cold stress applied to adult rats activates ovarian sympathetic innervation and develops polycystic ovary (PCO) phenotype. The PCO syndrome in humans originates during early development and is expressed before or during puberty, which suggests that the condition derived from in utero exposure to neural- or metabolic-derived insults. We studied the effects of maternal sympathetic stress on the ovarian follicular development and on the onset of puberty of female offspring. Timed pregnant rats were exposed to chronic cold stress (4 °C, 3 h/daily from 1000 to 1300 h) during the entire pregnancy. Neonatal rats exposed to sympathetic stress during gestation had a lower number of primary, primordial, and secondary follicles in the ovary and a lower recruitment of primary and secondary follicles derived from the primordial follicular pool. The expression of the FSH receptor and response of the neonatal ovary to FSH were reduced. A decrease in nerve growth factor (NGF) mRNA was found without change in the low-affinity NGF receptor. The FSH-induced development of secondary follicles was decreased. At puberty, estradiol plasma levels decreased without changes in LH plasma levels. Puberty onset (as shown by the vaginal opening) was delayed. Ovarian norepinephrine (NE) was reduced; there was no change in its metabolite, 3-methoxy-4-hydroxyphenylglycol, in stressed rats and no change in NE turnover. The changes in ovarian NE in prepubertal rats stressed during gestation could represent a lower development of sympathetic nerves as a compensatory response to the chronically increased NE levels during gestation and hence participate in delaying reproductive performance in the rat.


1962 ◽  
Vol 39 (3) ◽  
pp. 423-430
Author(s):  
H. L. Krüskemper ◽  
F. J. Kessler ◽  
E. Steinkrüger

ABSTRACT 1. Reserpine does not inhibit the tissue respiration of liver in normal male rats (in vitro). 2. The decrease of tissue respiration of the liver with simultaneous morphological stimulation of the thyroid gland after long administration of reserpine is due to a minute inhibition of the hormone synthesis in the thyroid gland. 3. The morphological alterations of the thyroid in experimental hypothyroidism due to perchlorate can not be prevented with reserpine.


2016 ◽  
pp. 166-170
Author(s):  
Y.V. Masliy ◽  
◽  
I.O. Sudoma ◽  
P.S. Mazur ◽  
D.A. Mykytenko ◽  
...  

The objective: to study the possibility of using frozen blastocysts for biopsy and genetic testing and performance measurement transfer euploeded 5–7-day-old embryos after thawing, biopsies, refreezing and thawing in patients with unsuccessful implantation. Patients and methods. The object of the study was the group of patients with repeated failure of implantation (4) in programs of auxiliary reproductive technologies (ART), subject to transfer to the uterus in total (i.e. in all the programs) for at least 6 good quality embryos based on morphological characteristics). All women had sufficient ovarian reserve. The patient was treated for infertility within the ART programs of the clinic of reproductive medicine "Nadiya" in the period from 2006 to 2016. The sample included couples who were not carriers of chromosomal rearrangements, without anomalies of the uterus (congenital and acquired: a doubling of the uterus, one-horned uterus, intrauterine membrane, synechia, submucous myoma of the uterus). All women had a positive ovarian response to controlled stimulation with gonadotropins (at least 7 oocytes) and a sufficient number of cryopreserved embryos. The first group (G1) included 64 women who trophectodermal a biopsy was performed on fresh blastocysts (in a loop controlled ovarian hyperstimulation). The second group (G2) were included 31 women who underwent thawing previously cryopreserved blastocysts trophectodermal re-biopsy and vitrification of blastocysts. Results. It was found that the performance of transfers euploid embryos that were vitrified, bioptrone and revitriphted, a little lower than those that were bioptrone fresh and vitrified only once. At the same time computationa genetic diagnosis previously vitrified blastocysts using comparative genome hybridization in patients with recurrent failed implantation allows to obtain a reasonable pregnancy rate (58%), implantation rate (33.3 %) and the birth of living children (45.1 %). Conclusion. Reprising biopropane embryos does not cause significant destructive impact and allows you to achieve pregnancy and birth of the alive child. Key words: in vitro fertilization, reusable unsuccessful implantation, a method of comparative genome hybridization, refreezing.


2016 ◽  
pp. 140-143
Author(s):  
N.V. Cotsabin ◽  
◽  
O.M. Makarchuk ◽  

The proportion of patients with multiple unsuccessful attempts of assisted reproductive technology (ART) is about 30% of all patients treated with the use of ART. Women with history of unsuccessful ART attempts - a special category of patients who require emergency attention and a thorough examination at the stage of preparation for superovulation stimulation,the selection of embryos and endometrium preparation for embryo transfer. The objective: to distinguish high-risk group of unsuccessful attempts based on a detailed analysis of anamnestic and clinical data of infertile women with repeated unsuccessful ART attempts that requires more in-depth study of hormonal features, ovarian reserve and condition of the endometrium. Materials and methods. For better understanding of the problem of repeated unsuccessful ART attempts and сreation of efficient infertility treatment algorithms for these couples we conducted a thorough analysis of anamnestic data of three groups of infertile women (105 patients), which were distributed by age: group I – younger than 35, the II group – from 35 to 40, the III group - over 40 years. These groups of patients were compared with each other and with the control group of healthy women (30 persons). Results. Leading stress factors in the percentage three times prevailed in the group of infertile women and had a direct connection with the fact of procedure «fertilization in vitro» and chronic stressors caused by prolonged infertility. Primary infertility was observed significantly more frequent in patients younger than 35 years (p <0.05), secondary infertility - mostly in the second and third experimental groups (p <0.05). Noteworthy significant percentage of wellknown causes of infertility and idiopathic factor in all groups, and the prevalence of tubal-peritoneal factor in the second and third experimental groups, and endocrine dysfunction in the I experimental group. The most common disorder among this category of woman was polycystic ovary syndrome. Frequency of usual miscarriage among patients of I ana II groups was two times higher than in the third group (p <0.05). Among the experimental groups the leading place belongs urinary tract infection, respiratory tract diseases, pathologies of the cardiovascular system. Data of the stratified analysis show an increase likelihood of repeated unsuccessful ART attempts under the influence of constant chronic stress (odds ratio OR=2.06; 95% CI: 0.95–3.17; p<0.05). Conclusions. Among infertile patients with repeated unsuccessful ART attempts must be separated a high risk group of failures. The identity depends on the duration of infertility, female age and leading combination of factors. Key words: repeated unsuccessful ART attempts, anamnesis, infertility, high risk.


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