The aim of this study is to evaluate pituitary-ovarian function at different postpartum periods during the lactational amenorrhea in order to understand the mechanism by which puerperal lactation is associated with a protracted period of amenorrhea and natural infertility. Ninety four lactating women and 119 lactating women with menstruation, aged between 21 and 38 years, volunteered for this study. The pituitary was relatively insensitive to LH-RH during the first 3 weeks following delivery. The recovery of FSH responsiveness to LH-RH occurred earlier than that of LH. Normal FSH response resumed in the 2nd week while the LH response, although not normal, started at the 3rd week postpartum. Pituitary responsiveness after the 5th week postpartum was similar to that occurring in normally menstruating women, except that FSH response was exagerated. Serum prolactin levels were elevated above 160 ng/ml until the 5th week postpartum and decreased to 84.2 ng/ml in the 6th week postpartum. It appears that at least one reason for anovulation during the first four weeks following delivery is the relative insensitivity of the pituitary to hypothalamic stimulation. Prolactin does not seem to modulate pituitary responsiveness to LH-RH. In order to clarify hormonal profiles during the lactational amenorrhea beyond the 5th week puerperium, serum levels of LH, FSH, prolactin, estradiol and progesterone were determined during different postpartum periods. Serum FSH and LH levels during 1-10 months postpartum were similar to basal levels seen during the normal menstrual cycle. Serum estradiol concentrations throughout 1-10 months postpartum, however, were significantly decreased as compared with the levels during the follicular phase of the normal menstrual cycle. Serum prolactin levels were elevated throughout 1-10 months postpartum in lactating amenorrhic women but decreased as the postpartum period lengthened. As compared with lactating amenorrhic women, lactating women with resumed menstruation showed a decrease in prolactin levels from 89.20 ng/ml to 51.39 ng/ml at 1-3 months, from 75.08 ng/ml to 49.99 ng/ml at 4-6 months, and from 54.73 ng/ml to 28.74ng/ml at 7-10 months postpartum. These results suggest that the apparent anovulation seen beyond 5th week postpartum during lactation was not due to pituitary insensitivity to LH-RH. Rather, prolactindependent mechanism interfering with cyclic activity may be operative during long term lactation.
Amenorrhea/etiology* ; Female ; Gonadorelin/pharmacology ; Gonadotropins, Pituitary/secretion ; Human ; Lactation* ; Ovary/physiology* ; Pituitary Gland/physiology* ; Pregnancy ; Prolactin/physiology ; Puerperium*

Leydig cells are the major source of androgens in males. Stem cells can be induced to differentiate into androgen-secreting Leydig like cells, whose functions are regulated by the hypothalamus and pituitary, so that they precisely secret the necessary hormones to maintain physiological function. Therefore, the establishment of an effective protocol to induce the differentiation of stem cells into androgen-secreting cells is very helpful for the treatment of hypogonadism caused by abnormalities of Leydig cells. This review outlines the recent findings concerning the differentiation of stem cells into androgen-secreting cells.
Androgens ; secretion ; Cell Differentiation ; physiology ; Humans ; Hypogonadism ; therapy ; Hypothalamus ; physiology ; Male ; Pituitary Gland ; physiology ; Stem Cells ; cytology ; secretion

Aging ; genetics ; physiology ; Diagnosis, Differential ; Humans ; Hypothalamo-Hypophyseal System ; physiology ; Kidney ; physiology ; Medicine, Chinese Traditional ; Neuroimmunomodulation ; physiology ; Pituitary-Adrenal System ; physiology ; Thymus Gland ; physiology ; Yang Deficiency ; physiopathology

BACKGROUNDThe presence of residual tumor after surgery for pituitary adenoma may necessitate further treatment. The suprasellar and parasellar extension of the tumor have been widely considered as the predictors for residual tumor. However there is scarcity of studies regarding the preoperative tumor volume and residual tumor. This study was conducted to evaluate if tumor volume could predict the outcome of transsphenoidal pituitary surgery.

METHODSA prospective study was designed and 48 patients who underwent transsphenoidal pituitary surgery within 1 year in the First Affiliated Hospital of Xi'an Jiaotong University were included in this study. The preoperative tumor volume and immediate postoperative tumor volume (within 4 - 7 days) were calculated in the contrast magnetic resonance imaging by using the formula of ellipsoid. All these volumes were divided into three subgroups, i.e. group 1, group 2 and group 3 with preoperative volume of less than 4 cm(3), 4 - 8 cm(3), and more than 8 cm(3) respectively. The parasellar and suprasellar extension of the tumor were also classified by Knosp and modified Hardy's classifications.

RESULTSBaseline characteristics were comparable. The preoperative tumor volume of more than 8 cm(3) (group 3, (12.1 ± 1.1) cm(3)) had increased risk on postoperative tumor residue (P < 0.01) than the other two groups ((2.1 ± 0.3) cm(3) and (6.1 ± 0.3) cm(3) in groups 1 and 2). The mean postoperative volume in group 3 patients ((2.2 ± 0.1) cm(3)) was significantly higher than the other two groups (P < 0.01).

CONCLUSIONPreoperative volume of more than 8 cm(3) can be considered as a predictor for postoperative residual volume.

Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Pituitary Gland ; pathology ; surgery ; Pituitary Neoplasms ; pathology ; surgery ; Prospective Studies ; Treatment Outcome ; Tumor Burden ; physiology ; Young Adult

OBJECTIVETo explore the mechanism of electroacupuncture (EA)-induced cumulative analgesic effects on chronic pain in rats with or without ovariectomy (OVX).

METHODSA total of 110 female Wistar rats were randomized into normal control (n=10), chronic constrictive injury (CCI, n=10), CCI+EA (n=30), OVX+CCI (n=30), and OVX+CCI+EA (n=30) groups. Each of the latter 3 groups was further divided into 2 days (2 d), 2 weeks (2 W) and 3 weeks (3 W) subgroups, respectively (n=10 in each subgroup). The CCI pain model was established by ligature of the right sciatic nerve, and the memory impairment model duplicated by OVX. The paw withdrawal latency (PWL, pain threshold) of the bilateral footplates was detected by radiant heat irradiation, and the bilateral difference in PWL (PWLD) was used to evaluate changes in the pain reaction. Morris water maze test was conducted for evaluating the rats' learning-memory ability. EA was applied to bilateral Zusanli (ST36) and Yanglingquan (GB34) for 2 d, 2 W and 3 W, respectively. Pituitary and hypothalamic beta-endorphin (EP) and adrenocorticotrophic hormone (ACTH) contents were detected by immunoradioassay.

RESULTSCompared with the CCI group, PWLD of the CCI+EA-3 W group decreased significantly (P<0.05). Compared with the OVX+CCI group, PWLD of the OVX+CCI+EA-3 W group was lowered considerably (P<0.05), but the value was markedly higher than its basal value and those of the normal control and CCI+EA groups (P<0.05). In comparison with the sham-OVX group, the escape latency, swimming distance (SD) in the target quadrant and total SD were increased remarkably in the OVX group (P<0.05), while the number of target platform crossings was decreased significantly (P<0.05), suggesting an impairment of the OVX rats' learning-memory ability. In simple CCI rats, both beta-EP and ACTH contents of the pituitary increased markedly (P<0.05), and those of the hypothalamus decreased obviously compared to the normal control group (P<0.05). After EA, pituitary and hypothalamic ACTH levels were significantly lowered at 2 d and hypothalamic ACTH and beta-EP contents increased obviously at 3 W in comparison with the CCI group (P<0.05). In OVX+CCI rats, following EA, pituitary beta-EP contents at 2 d, 2 W and 3 W, and hypothalamic beta-EP and ACTH contents at 2 W and hypothalamic ACTH levels at 3 W increased significantly (P<0.05), but hypothalamic beta-EP level at 3W decreased markedly (P<0.05). The effects of repeated EA in lowering pituitary ACTH and raising hypothalamic beta-EP and ACTH levels disappeared after OVX+CCI.

CONCLUSIONSRepeated EA has a cumulative analgesic effect, which is closely associated with its effects in regulating pituitary and hypothalamic beta-EP and ACTH levels. OVX may weaken the analgesic effect of EA by affecting hypothalamic-pituitary axis activity.

Adrenocorticotropic Hormone ; metabolism ; Animals ; Chronic Disease ; Electroacupuncture ; methods ; Female ; Hypothalamus ; metabolism ; Memory ; physiology ; Ovariectomy ; Pain Management ; Pituitary Gland ; metabolism ; Rats ; Rats, Wistar ; beta-Endorphin ; metabolism

OBJECTIVETo study the changes in endogenous neuregulin-1 (Nrg1) expression in the anterior pituitary of female Wistar-Furth rats in different phases of the estrous cycle.

METHODSFemale Wistar-Furth rats during estrous cycles were used. RT-PCR was employed to study the changes in the expression of Nrg1 isoforms and their cognate receptors ErbB-2 and ErbB-4 in the anterior pituitary in different phases of the estrous cycle. Western blotting was used to detect Nrg1 expression at the protein level. Immunofluorescence staining was used to identify hypophyseal cells expressing Nrg1 and observe the localization and distribution of Nrg1 and functional phosphorylation of ErbB-4. The co-expression of Nrg1 and ErbB-4 in the anterior pituitary of Rhesus monkey was also investigated.

RESULTSSome of the Nrg1 isoforms, especially type III Nrg1s, were expressed at a higher level during the estrous cycle I (E1) and estrous cycle II (E2), a result consistent with that of Western blotting for samples of the anterior pituitaries collected at these phases. Immunofluorescence staining identified the gonadotrophs as the main source of Nrg1, and showed an extensive distribution of Nrg1 in the anterior pituitary in E1 and E2 phases accompanied by apparent phosphorylated activation of ErbB-4. Adjacent distribution of Nrg1- and ErbB-4-positive cells was also observed in the anterior pituitary of male Rhesus monkeys.

CONCLUSIONOur results provide evidence for the expression of multiple Nrg1 isoforms and the presence of Nrg1/ErbB-4 signaling in the anterior pituitary of female Wistar-Furth rats. This signaling demonstrates an estrous cycle phase-related pattern. Additionally, Nrg1/ErbB-4-based juxtacrine signaling may exist in the anterior pituitary of male non-human primate.

Animals ; Estrous Cycle ; physiology ; Female ; Macaca mulatta ; Male ; Neuregulin-1 ; metabolism ; Phosphorylation ; Pituitary Gland ; metabolism ; Protein Isoforms ; metabolism ; Rats ; Rats, Inbred WF ; Receptor, Epidermal Growth Factor ; metabolism ; Receptor, ErbB-4

OBJECTIVETo observe the effect of low-dose triptorelin in later luteal phase on pituitary down-regulation for patients undergoing IVF-ET.

METHODSOne hundred and twenty patients were randomly divided into 2 groups(A and B). In group A, the patients were treated with triptorelin of 0.1 mg subcutaneously daily started on day 21 of menstrual cycle for 7 days. In group B, the patients were treated with long protocol of Buserelin intranasal spray. Comparisons were made between the groups in serum concentrations of FSH, LH, E2, T, PRL and P on the third day (D3) of superovulation cycle and on the day of hCG administration, highly purified follicle-stimulating hormone (HP) dosages, and so on.

RESULTSIn group A, mean serum LH level on D3 and the day of hCG was (1.55 +/- 0.99) U/L and (2.70 +/- 1.45) U/L, E2 was (85.66 +/- 13.13) pmol/L and (5,451.31 +/- 1,900.61) pmol/L, respectively, significantly lower than those of group B (P < 0.001; P < 0.01; P < 0.05; P < 0.001). Mean HP(75 IU/Amp) dosage per treatment cycle in group A was 28.20 +/- 11.03 ampoules, significantly higher than 22.30 +/- 6.40 ampoules in group B(P < 0.001).

CONCLUSIONSLow-dose triptorelin in later luteal phase is effective for down-regulation of pituitary and produces more suppression on endogenous LH in pituitary than Buserelin long protocol.

Adult ; Down-Regulation ; Embryo Transfer ; Estradiol ; blood ; Female ; Fertilization in Vitro ; Humans ; Injections, Subcutaneous ; Luteinizing Hormone ; blood ; Luteolytic Agents ; administration & dosage ; Pituitary Gland ; drug effects ; physiology ; Triptorelin Pamoate ; administration & dosage

With the generalized use of highly sensitive thyroid stimulating hormone (TSH) and free thyroid hormone assays, most thyroid function tests (TFTs) are straightforward to interpret and confirm the clinical impressions of thyroid diseases. However, in some patients, TFT results can be perplexing because the clinical picture is not compatible with the tests or because TSH and free T4 are discordant with each other. Optimizing the interpretation of TFTs requires a complete knowledge of thyroid hormone homeostasis, an understanding of the range of tests available to the clinician, and the ability to interpret biochemical abnormalities in the context of the patient's clinical thyroid status. The common etiologic factors causing puzzling TFT results include intercurrent illness (sick euthyroid syndrome), drugs, alteration in normal physiology (pregnancy), hypothalamic-pituitary diseases, rare genetic disorders, and assay interference. Sick euthyroid syndrome is the most common cause of TFT abnormalities encountered in the hospital. In hypothalamic-pituitary diseases, TSH levels are unreliable. Therefore, it is not uncommon to see marginally high TSH levels in central hypothyroidism. Drugs may be the culprit of TFT abnormalities through various mechanisms. Patients with inappropriate TSH levels need a differential diagnosis between TSH-secreting pituitary adenoma and resistance to thyroid hormone. Sellar magnetic resonance imaging, serum α-subunit levels, serum sex hormone-binding globulin levels, a thyrotropin-releasing hormone stimulation test, trial of somatostatin analogues, and TR-β sequencing are helpful for the diagnosis, but it may be challenging. TFTs should be interpreted based on the clinical context of the patient, not just the numbers and reference ranges of the tests, to avoid various pitfalls of TFTs and unnecessary costly evaluations and therapies.
Diagnosis ; Diagnosis, Differential ; Diagnostic Errors ; Euthyroid Sick Syndromes ; Homeostasis ; Humans ; Hyperthyroidism ; Hypothyroidism ; Magnetic Resonance Imaging ; Physiology ; Pituitary Neoplasms ; Rare Diseases ; Reference Values ; Sex Hormone-Binding Globulin ; Somatostatin ; Thyroid Diseases ; Thyroid Function Tests ; Thyroid Gland ; Thyrotropin ; Thyrotropin-Releasing Hormone

The effects of fluoride exposure on the functions of reproductive and endocrine systems have attracted widespread attention in academic circle nowadays. However, it is unclear whether the gene-environment interaction may modify the secretion and activity of hypothalamus-pituitary- ovarian (HPO) axis hormones. Thus, the aim of this study was to explore the influence of fluoride exposure and follicle stimulating hormone receptor (FSHR) gene polymorphism on reproductive hormones in Chinese women. A cross sectional study was conducted in seven villages of Henan Province, China during 2010-2011. A total of 679 women aged 18-48 years were recruited through cluster sampling and divided into three groups, i.e. endemic fluorosis group (EFG), defluoridation project group (DFPG), and control group (CG) based on the local fluoride concentration in drinking water. The serum levels of gonadotropin releasing hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were determined respectively and the FSHR polymorphism was detected by real time PCR assay. The results provided the preliminary evidence indicating the gene-environment interaction on HPO axis hormones in women.
Adolescent ; Adult ; Age Factors ; Asian Continental Ancestry Group ; China ; Cross-Sectional Studies ; Estradiol ; blood ; Female ; Fluoridation ; adverse effects ; Fluorides ; administration & dosage ; adverse effects ; urine ; Follicle Stimulating Hormone ; blood ; Gene-Environment Interaction ; Gonadotropin-Releasing Hormone ; blood ; Humans ; Hypothalamus ; physiology ; Luteinizing Hormone ; blood ; Middle Aged ; Ovary ; physiology ; Pituitary Gland ; physiology ; Polymorphism, Single Nucleotide ; Receptors, FSH ; genetics ; Tobacco Smoke Pollution ; Young Adult

Sleep deprivation (SD) has many deleterious health effects and occurs in more than 70% of pregnant women. However, the changes in sex hormones and relevant mechanisms after SD have not been well clarified. The aim of the present study was to explore the effects of SD on the secretion of sex hormones and the underlying mechanisms. Twelve pregnant Wistar rats were divided into control (CON, n = 6) and SD (n = 6) groups. Pregnant rats in the SD group were deprived of sleep for 18 h, and allowed free rest for 6 h, and then the above procedures were repeated until delivery. The CON group lived in a 12 h light/dark light cycle environment. Estradiol (E2) and progesterone (P4) levels were detected by enzyme-linked immunosorbent assay (ELISA), and the expression of circadian clock genes, Bmal1, Clock and Per2, in hypothalamus and pituitary gland tissues were evaluated by immunohistochemistry (IHC) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The PI3K and Akt phosphorylation levels in the hypothalamic and pituitary tissues were determined by Western blot. The results showed that, compared with the CON group, the SD group exhibited significantly reduced serum E2 and P4 levels, down-regulated Bmal1, Clock and Per2 expression, as well as decreased phosphorylation levels of PI3K and Akt. But there was no significant difference of the total PI3K and Akt protein expression levels between the two groups. These results suggest that SD might affect the expression of the circadian clock genes in the hypothalamus and pituitary via PI3K/Akt pathway, and subsequently regulate the secretion of sex hormones in the pregnant rats, which hints the important roles of SD-induced changes of serum sex hormone levels in the pregnant rats.
ARNTL Transcription Factors/metabolism* ; Animals ; Circadian Clocks/physiology* ; Circadian Rhythm/genetics* ; Female ; Gene Expression Regulation/genetics* ; Gonadal Steroid Hormones/metabolism* ; Hypothalamus/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Pituitary Gland/metabolism* ; Pregnancy ; Progesterone ; Proto-Oncogene Proteins c-akt/metabolism* ; Rats ; Rats, Wistar ; Signal Transduction ; Sleep Deprivation/metabolism*