Expression of brain prolactin releasing peptide (PrRP) changes in the estrous cycle of female rats

The aim of this study was to determine whether spinal cord stimulation (SCS) modulates activity of lumbosacral spinal neurons receiving input from the urinary bladder. Extracellular potentials of L6-S2 spinal neurons were recorded in pentobarbital anesthetized, paralyzed and ventilated male rats. SCS (50 Hz, 0.2 ms, 3-5 min, 90% motor threshold) was applied on the dorsal column of L2-L3 and C1-C2 segments and significantly reduced excitatory responses of 18/25 (72%) and 13/19 (68%) lumbosacral neurons to noxious urinary bladder distension (UBD, > or =1.0 ml, 20 s), respectively. SCS affected spinal neurons with either high- or low-threshold responses to UBD. These results suggested that SCS might have a potential therapeutic effect for patients with hypersensitivity and/or pain of cystitis and other urinary bladder disorders.     

GnRH在宫颈鳞状细胞癌中的表达及意义

目的:从蛋白质及核酸水平研究GnRH(促性腺激素释放激素)在宫颈鳞状细胞癌中的表达,以探讨其存在的临床意义。方法:采用免疫组化和原位杂交两种实验方法,分别从蛋白质和核酸水平检测45例宫颈鳞状细胞癌及20例慢性宫颈炎中GnRH的表达。结果:在20例慢性宫颈炎宫颈上皮组织中GnRH及GnRH mRNA表达均为阴性,而在45例宫颈鳞状细胞癌组织中,GnRH阳性表达率为80%,GnRH mRNA阳性表达率为64.44%,即无论是在蛋白质水平还是在核酸水平比较两者均显示差异有显著性;定性及定量比较GnRH及GnRH mRNA在不同临床期别的宫颈癌组织中的表达情况,结果为GnRH定性表达率Ⅰ期50%(6/12),Ⅱa期85.7%(18/21),Ⅱb-期100%(12/12);GnRH mRNA定性表达率,Ⅰb期33.3%(4/12),Ⅱa期71.4%(15/21),Ⅱb-期83.3%(10/12);GnRH及GnRH mRNA在定性上表达有显著差别(P<0.05)。结论:宫颈鳞状细胞癌组织存在较高的GnRH,其有可能参与宫颈鳞状细胞癌发生、发展,为进一步研究通过抑制GnRH的产生,减少宫颈癌的发生及治疗宫颈癌提供了一定的理论基础。     

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.     

Quantitative microdialysis determination of extracellular striatal dopamine concentration in male and female rats: effects of estrous cycle and gonadectomy

Sex differences in basal extracellular striatal dopamine concentrations in gonadectomized male and female rats have been reported previously. In the current experiment, estrous cycle-dependent variation, sex differences and the effect of gonadectomy on extracellular striatal dopamine concentrations were determined using quantitative microdialysis. Female rats were found to have significantly higher extracellular striatal dopamine concentrations in proestrus and estrus than in diestrus or after ovariectomy. In contrast, castration of male rats had no effect on extracellular striatal dopamine concentrations. Thus, endogenous ovarian hormones, but not testicular hormones, modulate extracellular striatal dopamine concentrations in rats.     

骨桥蛋白在动情周期与妊娠早期小鼠输卵管上皮的表达 

目的 探讨骨桥蛋白(OPN)在动情周期和妊娠早期小鼠输卵管的表达。方法 70只昆明雌性小白鼠分为动情周期组、妊娠组和假孕组,昆明雄性小白鼠15只用于与雌鼠合笼。取雌鼠动情周期、妊娠和假孕第1～5天的输卵管,利用免疫组织化学染色及半定量分析检测OPN在小鼠输卵管的定位和表达情况。结果 整个动情周期小鼠输卵管上皮组织OPN的免疫染色均呈阳性,动情期的输卵管上皮OPN染色的平均吸光度值（AEM>A/EM>）最高,动情间期组AA值最低;妊娠和假孕第1～5天小鼠输卵管上     

Orphanin FQ and glutamate connection in the regulation of gonadotropin-releasing hormone secretion in the preoptic area of conscious male rats

Utilizing the method of push-pull perfusion and radioimmunoassay (RIA), the secretory profile of gonadotropin-releasing hormone (GnRH) in the preoptic area (POA) and serum-luteinizing hormone (LH) levels were examined in conscious male rats after administration of [Nphe(1)]NC(1-13)NH(2), a competitive antagonists of the opioid receptor-like 1 receptor (ORL1 receptor) which is endogenous receptor for Orphanin FQ (OFQ). Glutamate release in the POA was also measured by high-performance liquid chromatography (HPLC) after perfusion of [Nphe(1)]NC(1-13)NH(2), i.e. NC13. The results showed that GnRH secretion from the POA and serum LH levels was increased significantly 40 min and 60 min, respectively after perfusion of 2 and 20 mmol/L NC13 in freely moving male rats (p<0.05). Pretreatment with a glutamate, N-methyl-D-aspartate (NMDA) receptor antagonist (MK-801, s.c., 0.2 mg/kg) abolished the increase of GnRH release in the POA induced by 2 mmol/L NC13. Additionally, 20 mmol/L NC13 significantly enhanced glutamate release in the POA at 40 min post-perfusion in a dose-dependent manner. These findings suggest that hypothalamic OFQ/ORL1 receptor system plays a role in the physiological inhibitory control of GnRH secretion in the POA of male rats, and provide evidence for involvement of an OFQ and glutamate pathway in the control of GnRH secretion.     

电针上调食源性肥胖致不孕大鼠下丘脑弓状核内GnRH的表达

目的 探讨电针对食源性肥胖致不孕大鼠中枢性作用中,能否上调下丘脑弓状核GnRH的表达.方法 将100只刚断乳雌性SD大鼠随机分为2组:①正常组20只,喂以普通饲料;②高能饲料组80只,给予高能饲料,筛选出肥胖不孕大鼠22只,并将其随机分成两组,即对照组和电针组.检测血清雌二醇(E2)、睾酮(T)、瘦素(leptin) ...     

Plasma and pituitary concentrations of LH,FSH, and Prolactin in aging C57BL/6 mice at various times of the estrous cycle

—Plasma and pituitary concentrations of LH, FSH, and prolactin (Prl) were measured by RIA in 2–4, 7–8, 12–13 and 16–20 month-old female C57BL/6 mice during various stages of the estrous cycle. In general, gonadotropin concentrations tended to rise with increasing age and Prl concentrations tended to decline. Pronounced differences existed, however, between the four age groups around the time of the LH surge. LH secretion declined progressively with increasing age at 21.00 hr of proestrus. Aged mice, 16–20 months old, had significantly lower plasma concentrations of LH than did other age groups. It is not known whether age-related changes in the ovary, pituitary, or hypothalamus are largely responsible for differences in the secretion of LH, FSH and Prl in aging C57BL/6 mice.     

Corticotropin releasing factor (CRF)-stimulation test in normal controls and patients with disturbances of the hypothalamo-pituitary-adrenal axis

Summary Intravenous application of 100 µg synthetic ovine corticotropin releasing factor (CRF) led to stimulation of ACTH-secretion in nine normal controls, with a maximum 30 min after CRF. Cortisol, corticosterone, cortisone and 11-deoxycortisol increased with a maximum at 60 min after CRF, whereas no rise was seen in aldosterone, 11-deoxycorticosterone, 17--hydroxyprogesterone, progesterone, DHEA-S and testosterone. The specificity of CRF-stimulation was also shown by unchanged TSH, LH, FSH, hGH, prolactin and thyroid hormone levels, als well as unchanged insulin and gastrin levels. No serious side-effects were observed during the test period and afterwards.CRF-tests were performed in ten patients with disturbances of the hypothalamo pituitary adrenal axis (HPAA). Preliminary findings show hyperresponsiveness of ACTH in all situations of ACTH-hypersecretion (two patients with Cushing's disease, one patient with Nelson's syndrome, and one with Addison's disease). In contrast, one patient with successful microadenomectomy showed no response of ACTH to CRF, whereas in another patient with a macroadenoma ACTH and cortisol-levels still increased postoperatively. Divergent patterns in ACTH-responsiveness to CRF were seen in four patients with secondary adrenal insufficiency, allowing the localization of the defect. These data point to the possible importance of the CRF-test as a differential diagnostic tool and prognostic factor in diseases of the HPAA.Mit Unterstützung der Deutschen Forschungsgemeinschaft (Sonderforschungsbereich 51)     

Stimulation of growth hormone secretion with human growth hormone releasing factors (GRF1–44, GRF1–40, GRF1–29) in normal subjects

Summary Peptides of different chain lengths (GRF^1–44, GRF^1–40, GRF^1–29) were given as a 50 µg i.v. bolus to five normal volunteers. Blood was collected before and until 120 min after GRF injection. No serious side effects were recorded. All GRF peptides led to a clearcut and significant increase of GH levels compared to placebo controls with the maximum occurring 15–30 min after GRF injection. There was no significant difference in the maximal GH increase after the different GRF peptides. When GRF^1–44 was administered to five normal subjects over 2 days in 6- and 18-h intervals, respectively, significant increase of GH levels were recorded after each injection compared to placebo controls. Again, there was no significant difference between the maximal GH rises during the different tests. These findings show that the short GRF^1–29 peptide may be used for diagnosis and therapy. In addition, in contrast to continuous infusion and administration of GRF in short intervals, GRF application in 6-h intervals leads to adequate GH responses.Abbreviations (h) GH (human) growth hormone - hpGRF human pancreatic growth hormone releasing factor Supported by the Deutsche Forschungsgemeinschaft (We 439/4-1) and the Fraunhofergesellschaft     

Expression of gastrin-releasing peptide (GRP) in the bovine uterus during the estrous cycle

Gastrin-releasing peptide (GRP) has been proposed as a novel regulatory peptide in the reproductive tract. We previously demonstrated that GRP immunoreactivities are found predominantly in the uterine gland epithelial cells of nonpregnant and pregnant cows. The present study focused on the distribution of GRP immunoreactivity and the expression of GRP mRNA in the bovine endometrium during the estrous cycle. Tissues were collected from 21 uterine horns and bodies during the estrous cycle. RT-PCR showed the expected GRP mRNA fragments (284 bp) in the tissues from all stages of the cycle. In situ hybridization results ascertained the expression of the GRP mRNA in the uterine gland epithelial cells and superficial epithelial cells of the endometrium. Positive staining of GRP immunoreactivity in the uterine gland epithelial cells was detected in both the uterine horn and body from all stages of the cycle. In metestrus and diestrus stages, GRP was also detected in the superficial epithelial cells of horn, but not in the body. The degrees of GRP mRNA expression and intensities of GRP immunoreactivity in the endometrium increased from proestrus to diestrus stages. These findings suggest that GRP may be important both in the endometrial remodeling during the estrous cycle and in the implantation and development of blastocysts.     

Dynamic changes of cell cycle elements in the ischemic brain after bone marrow stromal cells transplantation in rats

Transplantation of bone marrow stromal cells (BMSCs) improves animal neurological functional recovery after stroke. But the mechanism remains unclear. As cell cycle machinery plays an important role in stroke, we investigated the dynamic changes of cell cycle elements in a rat model of middle cerebral artery occlusion. We found the cell cycle markers, cdk4 along with its activator cyclin D1, and proliferating cell nuclear antigen (PCNA), increased after brain ischemia–reperfusion. Phosphorylation of the retinoblastoma protein (pRb, on ser-795), the cyclin D/cdk4 complex mutual target, was upregulated accordingly. However, intravenously administrated BMSCs facilitated cyclin D1, cdk4, and PCNA decrease in the ischemic cortex. Meanwhile, phospho-pRb (ser-795) was completely inhibited. On the contrary, endogenous cdk inhibitor p27 reduced before but enhanced after BMSCs treatment. These findings suggested BMSCs might modulate cell cycle progression in injured brain via downregulation of the cyclin D1/cdk4/pRb pathway as well as upregulation of p27 level. These results provide another way by which BMSCs may contribute to the recovery from stroke.     

The cystic fibrosis transmembrane conductance regulator (Cftr) modulates the timing of puberty in mice

Background

Delayed puberty is common among individuals with cystic fibrosis (CF) and is usually attributed to chronic disease and/or poor nutrition. However, it has recently been recognised that pubertal delay can occur even in the setting of good nutritional and clinical status. This finding, along with evidence that Cftr is expressed in rat brain, human hypothalamus, and a gonadotropin releasing hormone secreting cell line, raises the possibility that some of the pubertal delay in CF could stem directly from alterations in Cftr function that affect the hypothalamic‐pituitary‐gonadal axis.

Methods

To examine this hypothesis, we investigated pubertal timing (as assessed by vaginal opening (VO)) in a mouse model of CF (Cftr^tm1Unc) engineered to produce a truncated Cftr mRNA and referred to as S489X. Homozygous knockout, heterozygote, and wild type (WT) female mice were examined.

Results

As expected, the S489X⁻/S489X⁻ knockout mice, which have chronic inflammation and gastrointestinal disease, grew more slowly and had later onset of puberty than WT animals. We anticipated that the S489X⁻/S489X⁺ heterozygotes, which have no clinical CF phenotype, might display an intermediate timing of puberty. Surprisingly, however, these mice had earlier VO than WT. These findings were confirmed in a second, independent model of CF engineered to generate the ΔF508 mutation in mice. Again, the homozygotes displayed later pubertal timing, while the heterozygotes displayed earlier VO than the WT animals.

Conclusions

These data provide further evidence that Cftr can directly modulate the reproductive endocrine axis and raise the possibility that heterozygate mutation carriers may have a reproductive advantage.     

Studies on localization of calcitonin gene-related peptide (CGRP) in the thyroid-parathyroid complex

Summary Calcitonin gene-related peptide (CGRP) was localized by an immunocytochemical technique in the thyroid-parathyroid complexes of rat, guinea pig, rabbit, and in normal human thyroids and parathyroids. Human medullary carcinomas and parathyroid adenomas were also studied. In man and all animal species examined CGRP was present in the parafollicular cell, however, in guinea pigs only in small amounts. Except in rabbits, presence of CGRP was demonstrated in nerves of the thyroid and parathyroid capsule as well as in the nerve fibers of the capsular blood vessels. In the thyroid of guinea pigs CGRP was also noted in nerve fibers and in blood vessel walls between follicles. CGRP was also present in the parathyroid glands of rat and man, in nerve fibers localized between parathyroid cells. In rabbit the parafollicular cells between parathyroid cells also expressed CGRP immunoreactivity. No CGRP was noted in the parathyroids of the guinea pig. The proximity of parathyroid cells and CGRP containing tissue structures suggests a role for CGRP in the modulation of parathyroid hormone secretion. The importance of these regulatory mechanisms appear to be different in individual species.M. Dietel is a visiting Professor from the Institute of Pathology, University of Hamburg, Federal Republic of Germany     

Cellular proliferation in the anterior pituitary gland of normal adult rats: Influences of sex,estrous cycle,and circadian change

Proliferative activity of the anterior pituitary gland in 10 week-old male and female rats under normal conditions was investigated by counting mitotic figures and using single and double immunostaining of 5-bromo-2′-deoxyuridine (BrdU), proliferating cell nuclear antigen (PCNA), and six pituitary hormones. To determine which proliferative changes depend on the estrous cycle and circadian changes, respectively, six groups of female and two groups of male rats were studied at various times of day. Additionally, BrdU-incorporated cells were further classified by the six types of hormones they contained, or as immunonegative cells. Cell proliferative activity in the females fluctuated drastically with the highest activity in estrus and the lowest in diestrus. In the males, proliferative activity was at a relatively low level, and was similar to that in females in proestrus or early estrus, with the greater activity at night. Identified by their pituitary hormones, the distribution of the proliferating cells was almost the same in each sex, with prolactin (PRL) cells accounting for the highest proportion, followed by growth hormone (GH) cells, and adrenocorticotropic hormone (ACTH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and thyroid stimulating hormone (TSH) cells. These percentages agreed well with previously reported levels of cell types among all pituitary cells of the rat. It is therefore suggested that the life span and cycle of rat pituitary cells does not differ among cell types. In another test, male and female rats were given BrdU continuously via an osmotic pump for 8 days to compare cell proliferative activity between sexes, exclusive of the influence of estrous cycle and circadian changes. In this way, we were able to demonstrate that the cumulative incorporation of BrdU in females was consistently twice as high as in males over a constant period of time, and to conclude that cell renewal occurs at a doubled rate in the pituitary of female rat. © Wiley-Lis, Inc.     

Variation of fat intake with estrous cycle, ovariectomy and estradiol replacement in hamsters (Mesocricetus auratus) eating a fractionated diet

Intakes of fats, proteins, and carbohydrates were measured daily for a 3 month period in female hamsters maintained on a fractionated diet consisting of the dietary constituents, dextrose, fat and soybean meal. In the first study, hamsters showed variations in body weight and fat intake across the estrous cycle and following ovariectomy, with elevations during diestrous and after ovariectomy when endogenous estrogens are reduced. In the second study, the effects of exogenous estradiol or cholesterol on intake patterns of ovariectomized hamsters were determined. Hamsters lost weight and decreased fat intake when implanted with a silastic containing estradiol and gained weight and increased fat intake when exposed to cholesterol treatment. In neither of the two studies were the intakes of protein or carbohydrates significantly affected by the animals' hormonal status. These results suggest that in the hamster, estrogenic effects on food intake are specific to some dietary constituents and not to others.     

Effects of acute stress on the day of proestrus on sexual behavior and ovulation in female rats: participation of the angiotensinergic system

Physical or emotional stress can affect the female reproductive physiology and angiotensin II (Ang II) is a hormone that participates in the stress response and also in the control of reproductive hormones. The present study aimed at evaluating the effects of acute stress in the morning and afternoon of proestrus on sexual behavior and ovulation and the participation of Ang II in the stress-induced effects. Female rats with regular estrous cycles were used. Several different stress protocols were tested in the morning and in the afternoon of proestrus: restraint stress 10 min; restraint stress 1 h and ether stress, respectively. The participation of Ang II was evaluated by injecting Ang II receptor antagonists (losartan and PD123319) 15 min before stress. The lordosis quotient was recorded and the number of oocytes was counted. Plasma levels of luteinizing hormone, progesterone, prolactin and corticosterone were measured. All types of stress in the morning of proestrus induced a reduction in the number of oocytes. Restraint stress (1 h) in the afternoon of proestrus induced a significant reduction in the lordosis quotient. Peripheral and central losartan, but not PD123319, injections partly reverted the effects of stress on ovulation in the morning of proestrus. Acute stress in the morning of proestrus also reduced luteinizing hormone, progesterone and prolactin surges later on the same day. In conclusion, acute stress on the day of proestrus can affect female reproductive physiology. Moreover, the angiotensinergic system, through AT(1) receptors, participates in the effects of acute stress in the morning of proestrus.     

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.