Ovarian Function In Rats Research Articles

Human amnion-derived mesenchymal stem cell (hAD-MSC) transplantation improves ovarian function in rats with premature ovarian insufficiency (POI) at least partly through a paracrine mechanism

BackgroundChemotherapy can induce premature ovarian insufficiency (POI) and reduce fertility in young female patients. Currently, there is no effective therapy for POI. Human amnion-derived mesenchymal stem cells (hAD-MSCs) may be a promising seed cell for regenerative medicine. This study investigated the effects and mechanisms of hAD-MSC transplantation on chemotherapy-induced POI in rats.MethodsChemotherapy-induced POI rat models were established by intraperitoneal injection of cyclophosphamide. Seventy-two female SD rats were randomly divided into control, POI, and hAD-MSC-treated groups. hAD-MSCs were labeled with PKH26 and injected into the tail veins of POI rats. To examine the underlying mechanisms, the differentiation of transplanted hAD-MSCs in the POI ovaries was analyzed by immunofluorescent staining. The in vitro expression of growth factors secreted by hAD-MSCs in hAD-MSC-conditioned media (hAD-MSC-CM) was analyzed by ELISA. Sixty female SD rats were divided into control, POI, and hAD-MSC-CM-treated groups, and hAD-MSC-CM was injected into the bilateral ovaries of POI rats. After hAD-MSC transplantation or hAD-MSC-CM injection, serum sex hormone levels, estrous cycles, ovarian pathological changes, follicle counts, granulosa cell (GC) apoptosis, and Bcl-2, Bax, and VEGF expression in ovaries were examined.ResultsPKH26-labeled hAD-MSCs mainly homed to ovaries after transplantation.hAD-MSC transplantation reduced ovarian injury and improved ovarian function in rats with POI. Transplanted hAD-MSCs were only located in the interstitium of ovaries, rather than in follicles, and did not express the typical markers of oocytes and GCs, which are ZP3 and FSHR, respectively. hAD-MSCs secreted FGF2, IGF-1, HGF, and VEGF, and those growth factors were detected in the hAD-MSC-CM. hAD-MSC-CM injection improved the local microenvironment of POI ovaries, leading to a decrease in Bax expression and an increase in Bcl-2 and endogenous VEGF expression in ovarian cells, which inhibited chemotherapy-induced GC apoptosis, promoted angiogenesis and regulated follicular development, thus partly reducing ovarian injury and improving ovarian function in rats with POI.ConclusionshAD-MSC transplantation can improve ovarian function in rats with chemotherapy-induced POI at least partly through a paracrine mechanism. The presence of a paracrine mechanism accounting for hAD-MSC-mediated recovery of ovarian function might be attributed to the growth factors secreted by hAD-MSCs.

Mechanism of resveratrol in improving ovarian function in a rat model of premature ovarian insufficiency.

To investigate the mechanism of resveratrol treatment in chemically induced premature ovarian insufficiency (POI) in rats. Five-week-old specific pathogen-free healthy Sprague-Dawley female rats (n = 90) were randomly divided into five groups (n = 18): low-dose resveratrol (group A), moderate-dose resveratrol (group B), high-dose resveratrol (group C), model control group (group D) and blank control group (group E). POI was induced in rats from the resveratrol-treated groups and the model control group according to observed indexes using a previously established model (oral administration of tripterygium wilfordii polyglycoside tablet 50 mg/kg/day for 14 days). Western blot analysis was performed to compare levels of PI3K, p-PI3K, Akt, p-Akt, mTOR, p-mTOR, Bax, Bcl-2 and Caspase-3 in ovarian tissues of each group, and expression of p-Akt, p-mTOR, Bax, Bcl-2 and Caspase-3 was also evaluated by immunohistochemistry. Serum levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were determined using enzyme-linked immunosorbent assay. Compared with controls, we found that serum MDA decreased and SOD increased in resveratrol-treated groups. In addition, we found increased expression of p-PI3K, p-Akt, p-mTOR and Bcl-2, and decreased expression of Bax and Caspase-3 were observed in ovarian tissues of treated rats with POI. There was reduced ovarian function in POI rats compared with rats from the blank control group. Resveratrol reduced oxidative stress and inhibited apoptosis in granulosa cells by activating the PI3K/Akt/mTOR signaling pathway in a rat model of POI.

Effects of electroacupuncture at "Zhongliao" (BL 33) and "Tianshu" (ST 25) on ovarian function in rats with premature ovarian insufficiency

To explore the effects of electroacupuncture (EA) at "Zhongliao" (BL 33) and "Tianshu" (ST 25) on ovarian function in rats with premature ovarian insufficiency (POI). A total of 48 SD female rats with regular estrus were divided into a blank group (n=8), a model group (n=10), an EA group (n=10), a binding group (n=10) and a tamoxifen (TAM) group (n=10). The rats in the model group, EA group, binding group and TAM group were all treated with intraperitoneal injection of 4-vinylcyclohexene diepoxide (VCD, 160 mg/kg) for 15 consecutive days to establish the model of POI; the rats in the blank group were treated with normal diet. After the model was established successfully, the rats in the EA group were treated with EA at "Zhongliao" (BL 33) and "Tianshu" (ST 25) with continuous wave (1 to 3 Hz, 0.1 to 1 mA) for 20 minutes, once a day (five times a week) for the first two weeks and once every other day (three times a week) for the following two weeks. The rats in the TAM group were treated with subcutaneous injection of tamoxifen (1mg/kg), once a day (five times a week) for the first two weeks and once every other day (three times a week) for the following two weeks. The rats in the binding group were bound by a small sack as the EA group. The rats in the blank group and the model group were treated with normal diet. After four weeks, the sexual gland weight and index were tested in each group; the ELISA method was applied to test the level of anti-mllerian hormone (AMH) and inhibin B; the morphology of ovary was observed; the number of primordial follicles, primary follicle, antral follicle and atretic follicle was counted; the expression of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-1 receptor (IGF-1R) were measured. (1) Compared with the blank group, the ovary weight, ovary index, uterus weight and uterus index were significantly decreased after treatment in the model group, EA group, binding group and TAM group (all P<0.01); but the differences between the model group and the EA group, binding group, TAM group were not significant (all P>0.05). (2) Compared with the blank group, the levels of serum AMH, inhibin B and E2 were significantly reduced; the levels of FSH and LH were significantly increased in the model group; EA group, binding group and TAM group (all P<0.01). Compared with the model group, the levels of serum AMH, inhibin B and E2 were significantly increased, the level of FSH and LH were significantly reduced in the EA group and TAM group (all P<0.01). (3) Compared with the blank group, in the model group, EA group, binding group and TAM group the ovary was dark red and pale, surrounded by particle or not; the morphology was small and atrophic; the primordial follicles was reduced even vanished; the structure of primary follicle was damaged and loosely arranged; the mature follicle was few; the atretic follicle and interstitial gland were increased. (4) Compared with the blank group, the expressions of IGF-1 mRNA and IGF-1R mRNA were increased in the model group (all P<0.01); compared with the blank group, the expression of IGF-1 mRNA was increased in the binding group (P<0.05), but that of IGF-1R mRNA was not significantly different (P>0.05); compared with the model group, the expression of IGF-1 mRNA was not significantly different in the EA group, binding group and TAM group (all P>0.05), but that of IGF-1R mRNA was reduced (P<0.05, P<0.01). EA at "Zhongliao" (BL 33) and "Tianshu" (ST 25) has improvement effect on ovarian function in rats with VCD-induced POI, which is likely to be related to regulating the IGF-1R mRNA expression to improve the IGF-1/ IGF-1R axis.

Effects of low-intensity pulsed ultrasound (LIPUS)-pretreated human amnion-derived mesenchymal stem cell (hAD-MSC) transplantation on primary ovarian insufficiency in rats

BackgroundHuman amnion-derived mesenchymal stem cells (hAD-MSCs) have the features of mesenchymal stem cells (MSCs). Low-intensity pulsed ultrasound (LIPUS) can promote the expression of various growth factors and anti-inflammatory molecules that are necessary to keep the follicle growing and to reduce granulosa cell (GC) apoptosis in the ovary. This study aims to explore the effects of LIPUS-pretreated hAD-MSC transplantation on chemotherapy-induced primary ovarian insufficiency (POI) in rats.MethodsThe animals were divided into control, POI, hAD-MSC treatment, and LIPUS-pretreated hAD-MSC treatment groups. POI rat models were established by intraperitoneal injection of cyclophosphamide (CTX). The hAD-MSCs isolated from the amnion were exposed to LIPUS or sham irradiation for 5 consecutive days and injected into the tail vein of POI rats. Expression and secretion of growth factors promoted by LIPUS in hAD-MSCs were detected by real-time quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) in vitro. Estrous cycle, serum sex hormone levels, follicle counts, ovarian pathological changes, GC apoptosis, Bcl2 and Bax expression, and pro-inflammatory cytokine levels in ovaries were examined.ResultsPrimary hAD-MSCs were successfully isolated from the amnion. LIPUS promoted the expression and secretion of growth factors in hAD-MSCs in vitro. Both hAD-MSC and LIPUS-pretreated hAD-MSC transplantation increased the body and reproductive organ weights, improved ovarian function, and reduced reproductive organ injuries in POI rats. Transplantation of hAD-MSCs increased the Bcl-2/Bax ratio and reduced GC apoptosis and ovarian inflammation induced by chemotherapy in ovaries. These effects could be improved by pretreatment with LIPUS on hAD-MSCs.ConclusionBoth hAD-MSC transplantation and LIPUS-pretreated hAD-MSC transplantation can repair ovarian injury and improve ovarian function in rats with chemotherapy-induced POI. LIPUS-pretreated hAD-MSC transplantation is more advantageous for reducing inflammation, improving the local microenvironment, and inhibiting GC apoptosis induced by chemotherapy in ovarian tissue of POI rats.

Sodium fluoride activates ERK and JNK via induction of oxidative stress to promote apoptosis and impairs ovarian function in rats

The toxicity of sodium fluoride (NaF) to female fertility is currently recognized; however, the mechanisms are unclear. Previously, we reported a reduction in successful pregnancy rates, ovarian atrophy and dysfunction following exposure to NaF. The purpose of this study was to elucidate the underlying molecular mechanisms. Female Sprague-Dawley rats (10 rats/group) received 100 or 200mg/L NaF in their drinking water for 6 months or were assigned to an untreated control group. Apoptotic indices and oxidative stress indicators in blood and ovarian tissue were analyzed following sacrifice. The results confirmed the NaF-induced ovarian apoptosis, with concomitant activation of oxidative stress. Further investigations in ovarian granular cells showed that exposure to NaF activated extracellular regulated protein kinase (ERK) and c-Jun NH2 kinase (JNK), disrupting the ERK and JNK signaling pathways, while p38 and PI3K remained unchanged. These data demonstrated that oxidative stress may play a key role in NaF-induced ovarian dysfunction by activating the apoptotic ERK and JNK signaling pathways.

Blocking of β-Adrenergic Receptors During the Subfertile Period Inhibits Spontaneous Ovarian Cyst Formation in Rats

As aging proceeds, fertility problems arise, and the success rate of in vitro fertilization declines. During reproductive aging, rat ovaries present spontaneous formation of cysts, followed by a concomitant increase in sympathetic nerve activity, causing infertility and cessation of ovarian function. β2-Adrenergic receptors, which are activated by noradrenaline (NA), modify follicular development and steroid secretions; thus, increased nerve activity has been associated with the development and maintenance of cystic structures. The purpose of this work was to block the effect of this sympathetic activity through in vivo administration of propranolol (a β-adrenergic receptor antagonist) to determine whether it delays cyst formation and cessation of the ovarian function in rats that had reached the subfertile period. Propranolol was administrated daily to 8- and 10-month-old rats for 2 months. Estrous cycling activity was monitored by vaginal smear, serum concentration of the steroidal hormones was determined by enzyme-immune assay and morphological analysis of the ovaries was performed using 6 μm tissue slices stained with hematoxylin-eosin. Propranolol increased the number of healthy follicles, the ovulation rate, and levels of serum sexual steroids (androstenedione, testosterone, and estradiol) and recovered estrous cycling activity. It also decreased the number of follicular cysts. These results suggest that the blockade of β-adrenergic receptors recovered ovarian function during reproductive aging. It is suggested that propranolol induces a time-dependent extension of the subfertile window, and it could be used to increase the success rate of fertility programs in aging woman.

Increased weight gain after ovariectomy is not a consequence of leptin resistance.

The positive correlation between leptin and body fat mass has caused some investigators to speculate that leptin resistance contributes to obesity. Loss of ovarian function in human and rat is associated with increased fat mass gain and increased circulating leptin levels. To study whether ovariectomy produces leptin resistance, Sprague-Dawley female rats were ovariectomized or sham operated and injected with leptin for 35 days. Ovariectomy (OVX) produced hyperphagia and increased gain in both lean and fat mass. Daily leptin injections initially decreased food intake significantly, but feeding gradually increased to a stable level by day 16 and remained at that level for the duration of study. Body composition analysis indicated that chronic injection of leptin to OVX rats dramatically decreased (P < 0.05) fat mass [30 +/- 2 (SE) g, vehicle, to 3 +/- 1 g, leptin]. Using indirect calorimetry, we observed that OVX did not change energy expenditure or total level of fuel utilization. Leptin administration increased fat utilization and prevented reduction in calorie expenditure that is typically associated with food restriction. Leptin treatment to OVX rats decreased plasma triglyceride, free fatty acid, and insulin concentrations, whereas glucose concentration was normal. Withdrawal of leptin triggered hyperphagia, indicating that leptin biology remained throughout the duration of the chronic treatment. The same dose of leptin produced qualitatively similar data in sham-operated rats. Thus we concluded that the loss of ovarian function in rats is not associated with a change in leptin sensitivity.

Cadmium interferes with steroid biosynthesis in rat granulosa and luteal cells in vitro.

Recently, cadmium has been described to disturb ovarian function in rats. In this paper the direct influence of cadmium on steroid production of ovarian cells in vitro has been studied. Granulosa and luteal cells were obtained from proestrous and pregnant rats, and incubated with 0, 5, 10, 20 or 40 micrograms ml-1 CdCl2 in the presence or absence of 0.1-1000 ng ml-1 follicle stimulating hormone (FSH) or luteinizing hormone (LH) for 24 or 48 h. Production of progesterone (P) and 17 beta-estradiol (E2) by granulosa and that of P by luteal cells were measured by radioimmunoassay. In FSH-stimulated granulosa cell cultures, 5 and 40 micrograms ml-1 CdCl2 suppressed P accumulation to 65 and 10%, respectively; accumulation of E2 (at 5 micrograms ml-1 CdCl2) decreased to 44%. P production of LH-supported luteal cells dropped to 86 and 66%, respectively, when 5 and 40 micrograms ml-1 CdCl2 was added to the medium. No alteration in basal P accumulation occurred in granulosa and luteal cell cultures following incubations with 20 and 40 micrograms ml-1 CdCl2, whereas basal E2 production of granulosa cells was markedly diminished. It is concluded that CdCl2 suppressing steroid synthesis in vitro exerts a direct influence on granulosa and luteal cell function.

P-472 - Alternations of age-related change of the ovarian function in rats by chronic treatment with chlorpromazine

P-472 - Alternations of age-related change of the ovarian function in rats by chronic treatment with chlorpromazine

The role of follitropin and lutropin on the ovarian function in rats

Adult cycling female rats were treated with antisera to highly purified human follitropin and lutropin for eight days. The effect of this treatment on thein vitro steroidogenic response of the ovarian cells isolated from these rats to follitropin and lutropin has been investigated. Neutralisation of follitropin did not have significant effect on steroid production in response to lutropin. However, neutralisation of lutropin resulted in a very significant inhibition of response to both follitropin and lutropin.

Ovarian function in rats treated postnatally with progesterone

Ovarian function in rats treated postnatally with progesterone

Effect of prenatal administration of testosterone on ovarian function in rats

We have studied the effect of prenatal testosterone injections upon the ovarian function of the rat offspring. Two forms of testosterone were used: propionate in oil and hemisuccinate in aqueous solution. The injections were administered by different routes: subcutaneous, intraperitoneal, intrauterine extra-amniotic, and intra-amniotic. The destructive action of testosterone propionate upon gestation was confirmed, since, after repeated subcutaneous injections, surviving litters were obtained in only 25.8 percent. But these injections did not impede the normal function of the ovary in the offspring. In these rats, the decreased percentage of pregnancies was due to an anatomic abnormality of the vagina rather than to ovarian dysfunctions. Intraperitoneal and intrauterine extra-amniotic administration of testosterone propionate produced similar results. On the other hand, intra-amniotic injection produced anovulatory ovaries in almost two thirds of the cases. This effect is due to a specific action of the hormone. Injection of pure oil into the amniotic bag did not disturb the future ovarian function of the offspring. Testosterone hemisuccinate is ineffective in whatever form it is administered. The same negative result is obtained if a single injection of hemisuccinate is given to the newborn rat. Only repeated injections and higher dosages produce a sterilizing effect in 50 per cent of the cases. This indicates that the digerence between the action of propionate and hemisuccinate is due to the accelerated elimination and/or inactivation of the hormone when administered in aqueous solution. The results of the intra-amniotic administration of testosterone propionate prove that the hypophyseal-hypothalamic response of the female rat to testosterone is not limited to the first 5 days of extrauterine life but is already present in the prenatal period.

Functional and morphological state of the ovaries after hysterectomy

Hysterectomy provokes considerable changes of ovarian function in rats. This is primarily manifested in disturbance of the regularity of the sexual cycles. Persistence of rut is especially characteristic, it is evidently explained by a temporary excess of lutein, associated with a gradually inoreasing deficiency of the estrogenic hormone. Changes in the other stages of the sexual cycle are observed later with prolongation of the intervals between the rut periods. The ovaries continue to function.

Pathological effects and radioautographic localization of I131 in humans.

Pathological effects and radioautographic localization of I131 in humans.