Reaction of neurons of arcuate region of hypothalamus to microiontophoretic application of serotonin at different stages of the estrous cycle in rats

Sensitivity to serotonin was investigated in single neurons of the arcuate region of the hypothalamus as the center of tonic regulation of gonadotropic function in conditions of its microiontophoretic application in different stages of the estrous cycle in rats. It was shown that at the diestrus-II stage of the estrous cycle, especially during morning hours, cells predominate among neurons of the arcuate region with activated reaction to serotonin. During proestrus increased representation of cells with inhibited reaction is noted among spontaneously functioning neurons, which is especially pronounced during evening hours of this stage of the cycle. Serotonin induced reduction in the level of luteinizing hormone in blood and this effect was usually combined with an activating effect of indolamine on functioning of neurons. The combination of a delayed effect of the neurotransmitter on spontaneous activity of neurons of the arcuate nucleus with a reduced level of luteinizing hormone in blood was noted in the overwhelming majority of cases only at the proestrus stage.Translated from Fiziologicheskii Zhurnal SSSR imeni I. M. Sechenova, Vol. 69, No. 7, pp. 881–886, July, 1983.     

Structural and functional organization of the amygdala during the estrous cycle

Laboratory of Molecular Endocrinology, Institute of Experimental Endocrinology and Hormone Chemistry, Academy of Medical Sciences of the USSR, Moscow. Department of Human and Animal Physiology, Bashkir State University, Ufa. (Presented by Academician of the Academy of Medical Sciences of the USSR, Yu. A. Pankov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 107, No. 6, pp. 748–750, June, 1989.     

Changes in the oviducal epithelium during the estrous cycle in the marsupial Monodelphis domestica

The Monodelphis oviduct can be divided into four anatomical segments: preampulla (comprising fimbriae and infundibulum), ampulla, isthmus with crypts and uterotubal junction. Ovaries are enclosed in a periovarial sac, the bursa, and in some specimens tubules of an epoophoron could be identified. In both structures non-ciliated cells develop small translucent vesicles, which accumulate in the cell apices and presumably produce fluid as often seen in the bursa and in the tubules of the epooophoron. These vesicles do not stain with Alcian blue or PAS. The same applies also to the non-ciliated cells of the fimbriae. The oviducal epithelium of ampulla and the surface epithelium of the isthmus consisting of ciliated and non-ciliated, secretory cells undergo considerable changes during the estrous cycle. Proestrus shows low numbers of ciliated cells, some are in the process of neo-ciliogenesis, non-ciliated cells carry solitary cilia and few remnant secretory granules from the previous cycle may be found. At estrus the amount of ciliated cells in ampulla and isthmus has increased, most non-cililated cells lost the solitary cilia, developed longer microvilli and formed numerous secretory granules in their cell apices. At postestrus secretory products, often surrounded by membranes, are extruded into the oviducal lumen and contribute towards egg coat formation. First signs of deciliation processes are apparent. Solitary cilia reappear. At metestrus only few secretory cells are left with some secretory material. The lumen is often filled with shed cilia and cell apices. Proliferation of basal bodies within non-secretory cells indicate the formation of new ciliated cells. The non-ciliated epithelial cells of the isthmic crypts form no secretory granules but accumulate a great number of translucent vesicles, which in contrast to the secretory granules do not stain with Alcian blue or PAS.     

Monoamine content and activity of certain enzymes in the arcuate nucleus of the hypothalmus in young and aging rats during the estrous cycle

The arcuate nucleus and median eminence of the hypothalamus of young and aging female rats were investigated. In the course of the estrous cycle the monoamine (MA) content and the activity of monoamine oxidase (MAO) and NADP- and NAD-diaphorases were determined in the arcuate nucleus and the MA content and alkaline phosphatase activity in the median eminence. In young rats activity of NADP- and NAD-diaphorases and the MA content were increased and MAO activity reduced in proestrus-estrus, pointing to increased function of the nucleus in these phases of the estrous cycle. The accumulation of MA in the median eminence was observed in diestrus, but their content fell sharply in proestrus; alkaline phosphatase activity, on the other hand, rose considerably. In aging rats the dynamics of these indices was the same during the course of the estrous cycle. However, the level of functional activity of the arcuate nucleus was increased, and in the median eminence an increase in the concentration and disturbance of the liberation of MA from nerve endings were found.Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 7, pp. 861–864, July, 1976.     

青少年女性月经周期不同阶段加力对正畸牙移动的影响

背景：雌激素对正畸牙齿移动有影响,目前仅有动物实验证明,雌激素水平越低,正畸牙移动量越大,雌激素水平越高,正畸牙移动量越小。 目的：分析青少年女性正畸患者月经周期的不同时期加力对正畸牙移动的影响。 方法：选取12例14-18岁已具有月经初潮,月经规律,需要拔除上颌第1前磨牙的女性患者。采取自身对照,将患者上颌左右两侧尖牙,随机分为月经期加力组和排卵期加力组,应用种植体支抗加力远中移动尖牙,月经期加力组加力2周后排卵期加力组开始加力。各组分别于加力即刻及4周时取模,灌制超硬石膏模型,测量各组尖牙向远中移动的距离,采用GraphPad Prism5软件包对数据进行统计学分析。 结果与结论：月经期加力组尖牙移动量大于排卵期加力组(P < 0.05)。提示青少年女性正畸患者在月经期加力正畸牙的移动速度较排卵期正畸牙的移动速度显著增加,可有效缩短正畸矫治疗程。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Neuronal excitability in the periaqueductal grey matter during the estrous cycle in female Wistar rats

Extracellular recordings were made from output neurons in the dorsal half of the periaqueductal gray matter (dPAG) in urethane-anesthetized female Wistar rats. All the neurons were quiescent. A basal level of firing was therefore induced by continuous iontophoretic application of D,L-homocysteic acid (DLH). In the presence of the GABA(A) receptor antagonist bicuculline methiodide (BIC 0-30 nA) the DLH-induced firing increased further, revealing the presence of ongoing GABAergic inhibitory tone on the recorded neurons. The BIC-induced increase in firing rate was significantly greater in neurons recorded during estrus (Est) and late diestrus (LD) compared with proestrus (Pro) and early diestrus (ED) suggesting that GABAergic tone was lower in Est and LD. I.v. injection of the panicogenic cholecystokinin (CCK)(B) receptor agonist pentagastrin (PG, 40 microg kg(-1)) produced an increase in firing rate in 12/17 (70%) of neurons tested in the dPAG. Iontophoretic application of PG (10-30 nA) also produced a current-related increase in firing rate in 73.6% of the neurons tested. The excitatory response was reduced during application of the selective CCK(B) receptor antagonist beta-[2-([2-(8-azaspiro[4.5]dec-8-ylcarbonyl)-4,6-dimethylphenyl]amino)-2-oxoethyl]-(R)-napthalenepropanoic acid (CR2945) (60 nA, n=6). The PG-evoked increase in firing rate was significantly greater in neurons recorded during Est and LD compared with during Pro and ED. Juxtacellular labeling with neurobiotin in eight neurons revealed multipolar cells 12-44 microm diameter with up to six primary dendrites. In three of eight neurons, a filled axon was present and coursed without branching toward the perimeter of the periaqueductal gray matter (PAG). The estrous cycle-related change in responsiveness to BIC and PG suggests that the panic circuitry in the PAG may become more responsive to panicogenic agents during estrus and late diestrus as a consequence of a decrease in the intrinsic level of inhibitory GABAergic tone. The findings may have implications for understanding the neural processes that underlie the development of premenstrual dysphorias in women.     

Changes in dopamine sensitivity in isolated neurons of the preoptic region during the estrous cycle

The dopamine sensitivity of individual neurons of the midbrain preoptic region as a center of the cyclic regulation of hypophyseal gonadotropic function was investigated under conditions of dopamine microiontophoretic delivery during various stages of the estrous cycle in rats. It was shown that most neurons do not respond to dopamine during the diestrus-1 stage. The first half of the day of the diestrus-2 stage was characterized by a high representation of neurons with an activation response. Cells with an inhibitory response to dopamine were observed to increase among the spontaneously active neurons of the preoptic region starting from the second half of the day of this stage of the estrous cycle. The greatest quantity of neurons with an inhibitory response was observed during proestrus.Translated from Fiziologicheskii Zhurnal SSSR imeni I. M. Sechenova, Vol. 68, No. 3, pp. 331–336, March, 1982.     

Effects of different doses of nandrolone decanoate on estrous cycle and ovarian tissue of rats after treatment and recovery periods

This study tested the hypothesis that different doses of nandrolone decanoate (ND) will cause changes in the estrous cycle and ovarian tissue of adult rats; and investigated the duration of the recovery period that is sufficient to restore the damage in the animals treated with different doses. Wistar rats were treated with ND at doses of 1.87, 3.75, 7.5 and 15 mg/kg body weight, or received mineral oil (control group) for 15 days, subcutaneously. All animals were divided into three groups according to the treatment periods: (i) ND treatment for 15 days; (ii) ND treatment followed by a 30‐day recovery; and (iii) ND treatment followed by a 60‐day recovery. Estrous cycle was monitored daily, and at the end of each period, the animals were euthanized for histopathological analysis. During ND treatment and after 30‐day recovery, all animals exhibited persistent diestrus. After a 60‐day recovery, persistent diestrus was only maintained in the group that had received the highest dose. Ovarian weight was decreased significantly after the 30‐day recovery, regardless of ND doses, compared with the control group. There was a reduction (P < 0.05) in the number of corpora lutea and antral and growing follicles, in contrast to an increase (P < 0.05) in atretic follicles in a dose‐ and time‐dependent manner. Remarkable histopathological changes occurred in the ovaries of all ND‐treated groups. In conclusion, the different doses of ND caused changes in the estrous cycle and ovarian tissue of rats, and recovery periods (30 and 60 days) were insufficient to completely restore the damage in the animals treated with the highest dose.     

Unit activity in the hypothalamic arcuate area in rats at different stages of the estrous cycle

Changes in sensitivity to dopamine in various stages of the estrous cycle were studied in rats by microiontophoretic application to single neurons of the hypothalamic region and recording unit activity. Most arcuate neurons during the first half of the day in proestrus were shown to respond to dopamine by activation, to correspond to the raised plasma estrogen level in this phase of the estrous cycle. During the second half of the day in proestrus, when the estrogen level is minimal, and in stage diestrus-2, of all the neurons recorded the great majority responded to dopamine by inhibition.Translated from Fiziologicheskii Zhurnal SSSR imeni I. M. Sechenova, Vol. 62, No. 4, pp. 516–522, April, 1976.     

Electron-microscopic characteristics of neuroendocrine neurons in the amygdaloid body of the brain in male rats and female rats at different stages of the estral cycle

The ultrastructural features of neuroendocrine neurons in the dorsomedial nucleus (DMN) of the amygdaloid body of the brain — one of the major zones of sexual dimorphism — in 12 Wistar rats weighing 250–300 g were studied in three males and nine females at different stages of the estral cycle. On the basis of ultrastructural characteristics, analysis of the functional states of an average of 50 DMN neurons were studied in each animal. A morphofunctional classification reflecting hormone-dependent variations in neuron activity is proposed. DMN neurons were found to be in different structural-functional states, which could be classified as the states of rest, moderate activity, elevated activity, tension (maximal activity), decreased activity (types 1 and 2, depending on prior history), return to the initial state, and apoptosis. At the estrus stage, there was a predominance of neurons in the states of elevated activity (40% of all cells) and maximal activity (26%). At the metestrus stage, neurons in the state of decreased activity type 1 (with increased nuclear heterochromatin content) predominated (30% of cells), while 25% and 20% of cells were in the states of maximal activity and elevated activity respectively. In diestrus, neurons in the resting state, in moderate and elevated activity, in maximal activity, and in decreased activity type 1 were present in essentially identical proportions (18%, 21%, 18%, 20%, and 16% respectively). In males, 35% and 22% of neurons were in the states of elevated and maximal activity respectively. Neuron death was seen only in males. __________ Translated from Morfologiya, Vol. 130, No. 6, pp. 25–29, November–December, 2006.     

Parameters of estrous cycles in albino rats normally and after injection of xenogenic cerebrospinal fluid

We studied biological effects of xenogenic cerebrospinal fluid. Injection of the liquor to albino female rats during different periods of postnatal ontogeny induced changes in the dynamics of estrous cycles. Changes in the picture of vaginal smears, duration of estrous cycles, and proportion between their phases were found. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 8, pp. 213–215, August, 2007     

Uterine glandular area during the menstrual cycle and the effects of different in-vitro fertilization related hormonal treatments

The human uterine glandular epithelium undergoes a sequenceof well characterized changes during the menstrual cycle thatpresumably play an important role in preparation for blastocystimplantation. The aim of this study was to measure objectivelyglandular volume over the entire menstrual cycle and comparethe results with eight different clinical superovulation orhormone replacement therapy (HRT) subject groups. Endometrialbiopsies were taken from control normal menstrual cycle subjects(n = 96), and eight other smaller groups of women who had receiveddifferent in-vitro fertilization (TVF) related treatments. Thetotal area of glandular epithelium was objectively measuredfrom routine histological slides using computerized image analysis.Control menstrual cycle results showed a significantly greatergland area in the early secretory stage of the cycle than atany time between the early proliferative through to the mid-lateproliferative stages (P < 0.05). FVF patients receiving clomiphenecitrate and human menopausal gonadotrophin had a significantlysmaller glandular area than those in the control groups at equivalentstages of the menstrual cycle. The use of progesterone supplementationremoved this significant difference. Patients on the ‘Flare"regime had the highest gland area, although this was not significantlydifferent from controls. Buserelin down-regulation gave a glandarea that was closest to the normal cycle controls. The threeHRT groups showed high variability in gland volume between patients.The results from this study demonstrate that superovulationcan cause significant alterations in endometrial gland volume,but that these do not necessarily preclude implantation.     

Hippocampal levels of gamma-enolase, C-1-tetrahydrofolate synthase and serotransferrin fluctuate over the estrous cycle in the rat

Hippocampal functions vary across the estrous cycle but metabolic changes at the protein level have not been systematically studied so far. It was therefore the aim of the study to screen expression of metabolic proteins mainly represented by metabolic enzymes in the hippocampus over the estrous cycle and in males. Female and male OFA Sprague-Dawley rats were used and female estrous phases were determined by vaginal smears, according to which females were separated into groups of proestrous, estrous, early and late metestrous and diestrous. Proteins were extracted from hippocampal tissue and separated on two-dimensional gel electrophoresis followed by identification with mass spectrometry methods (MALDI-TOF-TOF and nano-LC-ESI-MS/MS). Comparative analysis of protein levels was carried out by quantifying protein spot volumes by means of specific software. Levels of one expression form of gamma-enolase were different between diestrous and early metestrous; C-1-tetrahydrofolate synthase levels were elevated in proestrous as compared with estrous and serotransferrin levels were increased in diestrous as compared with proestrous, estrous, metestrous and in males. The outcome of estrous cycle- and gender-dependent protein fluctuations is relevant for the interpretation of previous and future work as well as for the design of further studies at the protein level in the hippocampus.     

Duration of the mitotic cycle of mouse liver cells at different stages of carcinogenesis induced by orthoaminoazotoluene

Mice were given orthoaminoazotoluene for 9 months. The duration of the G₂ and S periods of the mitotic cycle was determined by an autoradiographic method and the duration of mitosis was determined by a stathmokinetic method using colcemid for hepatocytes from intact liver and for cells of adenomatous nodules and primary hepatomas. The duration of the S period for cells of the intact liver and of the adenomatous nodules was shown to be identical (13.8 and 13.9 h respectively), whereas for hepatoma cells it was reduced to 12.8 h. The duration of the G₂ period did not change substantially in the course of carcinogenesis and ranged from 2.2 to 2.7 h. The mean diurnal duration of mitosis likewise was unchanged at about 1 h. The increase in the number of mitoses and of DNA-synthesizing cells in hepatomas results from the entry of a larger number of cells into mitosis and into the S period and not from an increase in the duration of the M- and S periods of the mitotic cycle.Department of Biology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 1, pp. 61–64, January, 1978.     

Sexual preference in female rats during estrous cycle, pregnancy and lactation.

Choice of a male or female social contact was studied in intact female rats in a runway-choice apparatus during estrous cycle, pregnancy, and lactation. The male was chosen significantly more often during proestrus/estrus than during the diestrous days of the cycle. During pregnancy this preference in choice declined only to reappear gradually during the lactation period. The shifts in the level of motivation to seek out the male support previous studies and point to the significance of estrogen in producing the preference for the male.     

Substance P variations in the hypothalamus of golden hamsters at different stages of the estrous cycle.

The changes in substance P concentrations in the hypothalamus of female golden hamsters were studied at the different stages of the estrous cycle. Substance P levels in the hypothalamus of hamsters were highest during estrus and lowest during diestrus I and proestrus. The concentrations of substance P during diestrus II were not significantly different from those observed during estrus. These results show that substance P levels in the hypothalamus of female hamsters undergo significant changes during the estrous cycle.     

Functional morphology of the submaxillary salivary glands during age involution in albino rats

A quantitative study was made of the morphological and functional characteristics of different parts of the submaxillary salivary glands of albino rats in different stages of involution of the neuroendocrine system. During aging the salivary gland function of rats is preserved, and just as in young animals, clear cyclic fluctuations are observed depending on the phases of the estrous cycle, although the basal level of proteins and mucopolysaccharides is reduced, to correspond on average to the minimal found in young animals. Meanwhile activation of the enzymes responsible for energy and transport processes in the cell is observed and relations between the enzymes are altered. The results prove that the salivary glands are connected with the endocrine system and they confirm the view that in early age involution what occurs is not so much a change of function as a disturbance of relations between the different indices of functional activity of the organ.Department of Pathological Anatomy, I. P. Pavlov First Leningrad Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. K. Kulagin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 12, pp. 736–739, December, 1979.     

Expression of repulsive guidance molecule b (RGMb) in the uterus and ovary during the estrous cycle in rats

Repulsive guidance molecule b (RGMb; a.k.a. Dragon), initially identified in the embryonic dorsal root ganglion, is the first member of the RGM family shown to enhance bone morphogenetic protein (BMP) signaling by acting as a BMP co-receptor. BMP signaling has been demonstrated to play an important role in the reproductive organs. Our previous study found that RGMb was expressed in the reproductive axis, but whether RGMb expression in reproductive organs changes across the estrous cycle remains unknown. Here, we show in the rat that RGMb mRNA expression in the uterus was significantly higher during metesterus and diestrus than during proestrus and estrus. Western blotting indicated that RGMb protein was significantly lower during estrus compared with the other three stages. Immunohistochemistry revealed that RGMb protein was mainly localized to the uterine luminal and glandular epithelial cells of the endometrium. RGMb mRNA and protein in the ovary remained unchanged during the estrous cycle. RGMb protein was expressed in the oocytes of all follicles. Weak staining for RGMb protein was also found in corpora lutea. RGMb was not detected in granulosa cells and stromal cells. Taken together, RGMb expression in the uterus and ovary across the estrus cycle demonstrate that RGMb may be involved in the regulation of uterine function, follicular development as well as luteal activity.     

Effect of estradiol on spontaneous single unit activity in the arcuate region of the rat hypothalamus at various stages of the estrous cycle

Microiontophoretic injection of estradiol into the arcuate region of the hypothalamus in the overwhelming majority of experiments enhanced single unit activity. The response was more marked in diestrus-1 and diestrus-2 than in proestrus. It is suggested that changes in the predominant response of arcuate neurons to injection of estradiol in the course of the sex cycle are determined by the level of endogenous estrogens and pituitary gonadotropic hormones in the peripheral blood.Laboratory of Physiology of the Endocrine System, Institute of Experimental Endocrinology and Hormone Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 220–223, February, 1977.