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At least 685 records · Page 38Linked to original sources
PubMed1994

Plasticity of NO synthase expression in the nervous and endocrine systems.

Using immunohistochemistry and in situ hybridization the effect of nerve injury and of hormones was analysed in sensory and hypothalamic systems and in the pituitary gland. After peripheral axotomy a marked increase in NOS protein and mRNA levels was observed in dorsal root ganglia, the trigeminal ganglion and a less dramatic effect in the nodose ganglia. This effect lasted in the dorsal root ganglion neurons for at least 10 weeks. In the hypothalamic magnocellular neurons a transient increase was observed in the paraventricular and supraoptic nuclei. A similar effect was also seen after salt loading. In the anterior pituitary gland NOS was expressed in gonadotrophs and folliculo-stellate cells. Castration markedly increased NOS levels in the anterior lobe, and this could be counteracted by steroid hormone replacement. Thus, the present results show that the constitutive, neuronal NOS can be dramatically regulated in response to various manipulations, suggesting an important involvement of NO in these situations.

Amino Acid Oxidoreductases↗
PubMed1985

Histamine-containing peripheral neuronal and endocrine systems.

An immunohistochemical method was developed to detect histamine in tissues. The aim of this study was to reveal the cellular stores of histamine in the gastrointestinal tract, pituitary, and adrenal gland. Histamine-containing nerve fibers were found in both rat and guinea pig gut. The origin of at least some of these fibers in the rat ileum was the submucous ganglion cell layer. In the rat stomach, numerous enterochromaffin-like cells exhibited histamine immunofluorescence, and endocrine cells in the ileum and jejunum contained histamine. Only mast cells contained histamine in the neurohypophysis. A large number of process-bearing cells in the guinea pig but not in the rat adrenal medulla contained histamine. The study shows that histamine is present in peripheral nerves and endocrine cells in addition to mast cells, and may function as a neurotransmitter or hormone.

Adrenal Glands↗
PubMed2003

Endometriosis: interaction of immune and endocrine systems.

Endometriosis is a common gynecologic disorder characterized by the presence of endometrial tissue outside the uterine cavity. Although no single theory can explain all cases of endometriosis, the most commonly accepted theory is Sampson's theory of retrograde menstruation. Retrograde menstruation occurs in 76 to 90% of women. The much lower prevalence of endometriosis suggests that additional factors determine susceptibility to endometriosis. Endometriosis is associated with changes in both cell-mediated and humoral immunity. Impaired natural killer cell activity resulting in inadequate removal of refluxed menstrual debris may play a role in the development of endometriotic implants. Moreover, although the peritoneal fluid of women with endometriosis contains increased numbers of immune cells, these seem to facilitate rather than inhibit the development of endometriosis. Macrophages that would be expected to clear endometrial cells from the peritoneal cavity appear to enhance their proliferation by secreting growth factors and cytokines. Although it is unclear whether these immunologic alterations induce endometriosis or are a consequence of its presence, they appear to play an important role in allowing endometriosis implants to persist and progress and contribute to the development of associated infertility and pelvic pain. Danazol and gonadotropin-releasing hormone (GnRH) agonists are commonly used for the medical treatment of endometriosis. These medications seem to down-regulate cellular and humoral immune responses concomitant with their effect on endometriotic implants. Immunomodulatory effects of danazol and GnRH agonists are likely to contribute to the observed clinical improvement associated with their use.

Antibody Formation↗
PubMed1990

[Studies on the influence of acute maternal stress on the fetal endocrine system in late gestation of rats].

Prenatal stress affects fetal androgen milieu in the critical period of androgen-dependent brain differentiation, and induces permanent defects in reproductive functions of the offspring. We investigated the response of the fetal hypothalamo-pituitary-adrenal axis and the function of the placenta during an acute maternal stress, in order to clarify the mechanism of central endocrine regulation in the fetus with an inappropriate androgen level under stress. Pregnant rats at day 20-21 of gestation were subjected to forced immobilization stress. The plasma concentration of corticosterone (B) and ACTH, and tissue content of CRF and beta-EP like immunoreactivities (CRF-LI, beta-EP-LI) in the maternal and fetal hypothalamus and the placenta were measured by RIA. 3H-B was administered intravenously to pregnant rats and radioactivity was measured in blood and the hypothalamus. 1. In mothers, plasma B and ACTH increased at 20 and 60 minutes of stress. Hypothalamic CRF-LI decreased and beta-EP tended to decrease during stress. 2. In fetuses, plasma B and ACTH increased significantly during maternal stress. 3. Fetal hypothalamic CRF-LI and beta-EP-LI decreased significantly in males and females under maternal stress. 4. beta-EP-LI in the placenta decreased significantly after 120 minutes of stress, and beta-EP-LI was localized in trophoblast. No CRF-stained cell was detected in the placenta. 5. 3H-B given to mothers passed through the placenta, and the maximum radioactivity in fetal blood and the hypothalamus was found at 20 minutes after the injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

p34cdc2 homologue is located in nucleoli of the nervous and endocrine systems.

p34cdc2 protein kinase is a component of M phase-promoting factor (MPF), which plays an important role in controlling the mitotic and meiotic cell cycle. p34cdc2 contains a unique 16 amino acid sequence (PSTAIR) that is conserved from fission yeast to human. Using polyclonal anti-PSTAIR antibody, we detected the p34cdc2 homologue in the central nervous system of adult mice by western blotting. By immunohistochemical technique, we found that the p34cdc2 homologue was located in the nucleoli of neurons and glia in the central and peripheral nervous systems. In the central nervous system, positive cells were widely distributed from the cerebral cortex to the spinal cord. Immunoreactive cells were also detected in retina and pituitary. The evidence that the p34cdc2 is present in neurons which have lost the ability of cell division predicts another function of p34cdc2 family proteins besides the one that has generally recognized.

Amino Acid Sequence↗
PubMed1996

Effects of space flight on endocrine system function in experimental animals.

The effects exposing rats to space flights of various lengths in a series of COSMOS satellites are reported based on an evaluation of plasma hormone levels and several enzyme activities in the tissues. The results after space flights are compared with those obtained from rats exposed to acute or repeated stress. Space flight induced selective morphological responses in the corticotrophs and gonadotrophs of the pituitary. Plasma levels of ACTH did not change, but plasma growth hormone and TSH levels decreased after longer space flights (>14 days), while prolactin in the plasma increased after short flights (5-7 days). Plasma corticosterone was higher after all flights. Catecholamine levels in plasma increased only after long space flights. These changes in plasma hormone levels affected the activities of enzymes involved in the amino acid metabolism of the liver and lipolysis in the adipose tissues. Norepinephrine level and catecholamine synthesizing enzyme activity in the hypothalamus did not change in flight rats. The norepinephrine content, however, decreased in several nuclei selected from the hypothalamus of flight rats. Increases in plasma insulin and glucose were noted in rats after space flight. Glucagone values in plasma remained unchanged. Comparing these results from flight rats against rats exposed to acute or repeated stress indicate that long stays in microgravity do not represent intensive stressogenic stimulus of the adrenocortical and sympathetic adrenomedullar systems, and hormone alterations observed after space flight may be due primarily to acute stressor activity resulting from a return to Earth's gravity (gravitational stress).

Adaptation, Physiological↗
PubMed1984

Effects of hysterectomy and uterine extracts on the endocrine system of adult, nonpregnant rats.

Plasma concentration and anterior pituitary content of growth hormone (rGH), thyroid stimulating hormone (rTSH), prolactin, follicle stimulating hormone (rFSH), luteinizing hormone (rLH) as well as the plasma concentrations of triiodothyronine (T3), thyroxine (T4), corticosterone and immunoreactive somatomedin A (SM-A) have been determined in intact, ovariectomized or ovo-hysterectomized rats with and without treatment with steroid-free uterine extracts. The endocrine organs were weighed. Two weeks after hysterectomy the body weight was decreased, the weight of adrenals was increased, the plasma GH concentrations increased and the plasma TSH and T3 concentrations were decreased compared to the sham operated controls. Treatment with steroid-free uterine extracts had opposite effects; furthermore, a reduction of pituitary FSH, GH and prolactin content was observed. Plasma immunoreactive SM-A concentrations were not significantly influenced by this treatment, but there was a positive correlation between the body weight and SM-A and a negative correlation between the plasma GH and plasma SM-A concentrations regarding the individual values of hysterectomized, uterine-extract-treated and ovariectomized animals. The results suggests that uterine factors can influence the synthesis and release of several hormones and the weight of some endocrine organs in adult, nonpregnant rats.

Animals↗
PubMedDate not supplied

Human health effects of dioxins: cancer, reproductive and endocrine system effects.

Polychlorinated dioxins, furans and polychlorinated benzene constitute a family of toxic persistent environmental pollutants. In Europe, environmental concentrations increased slowly throughout this century until the late 1980s. Dioxins have been shown to be carcinogenic in animals and humans. In humans, excess risks were observed for all cancers, without any specific cancer predominating. In specific cohorts, excess risks were observed for reproductive cancers (breast female, endometrium, breast male, testis) but, overall, the pattern is inconsistent. In animals, endocrine, reproductive and developmental effects are among the most sensitive to dioxin exposure. Decreased sperm counts in rats and endometriosis in rhesus monkeys occur at concentrations 10 times higher than current human exposure. In humans, results are inconsistent regarding changes in concentrations of reproductive hormones. A modification of the sex ratio at birth was described in Seveso. There exist no data on effects such as endometriosis or time-to-pregnancy. Small alterations in thyroid function have occasionally been found. Increased risk for diabetes was seen in Seveso and a herbicide applicators cohort but, overall, results were inconsistent. Experimental data indicate that endocrine and reproductive effects should be among the most sensitive effects in both animals and humans. Epidemiological studies have evaluated only a few of these effects.

Dioxins↗