The principal modulators of the hypothalamic-pituitary-adrenal (HPA) axis are corticotropin-releasing hormone (CRH) and arginine-vasopressin (AVP). Corticotropin-releasing hormone is not exclusively produced in the hypothalamus. Its presence has been demonstrated at peripheral inflammatory sites. Ovulation and luteolysis bear characteristics of an aseptic inflammation. CRH was found in the theca and stromal cells as well as in cells of the corpora lutea of human and rat ovaries. The cytoplasm of the glandular epithelial cells of the endometrium has been shown to contain CRH and the myometrium contains specific CRH receptors. It has been suggested that CRH of fetal and maternal origin regulates FasL production, thus affecting the invasion (implantation) process through a local auto-paracrine regulatory loop involving the cytotrophoblast cells. Thus, the latter may regulate their own apoptosis. During pregnancy, the plasma level of circulating maternal immunoreactive CRH increases exponentially from the first trimester of gestation due to the CRH production in the placenta, decidua, and fetal membranes. The presence in plasma and amniotic fluid of a CRH-binding protein (CRHbp) that reduces the bioactivity of circulating CRH by binding is unique to humans. Maternal pituitary ACTH secretion and plasma ACTH levels rise during pregnancy-though remaining within normal limits-paralleling the rise of plasma cortisol levels. The maternal adrenal glands during pregnancy gradually become hypertrophic. Pregnancy is a transient, but physiologic, period of hypercortisolism. The diurnal variation of plasma cortisol levels is maintained in pregnancy, probably due to the secretion of AVP from the parvicellular paraventricular nuclei. CRH is detected in the fetal hypothalamus as early as the 12th week of gestation. CRH levels in fetal plasma are 50% less than in maternal plasma. The circulating fetal CRH is almost exclusively of placental origin. The placenta secretes CRH at a slower rate in the fetal compartment. AVP is detected in some neurons of the fetal hypothalamus together with CRH. AVP is usually detectable in the human fetal neurohypophysis at 11 to 12 weeks gestation and increases over 1000-fold over the next 12 to 16 weeks. The role of fetal AVP is unclear. Labor appears to be a stimulus for AVP release by the fetus. The processing of POMC differs in the anterior and intermediate lobes of the fetal pituitary gland. Corticotropin (ACTH) is detectable by radioimmunoassay in fetal plasma at 12 weeks gestation. Concentrations are higher before 34 weeks gestation, with a significant fall in late gestation. The human fetal adrenal is enormous relative to that of the adult organ. Adrenal steroid synthesis is increased in the fetus. The major steroid produced by the fetal adrenal zone is sulfoconjugated dehydroepiandrosterone (DHEAS). The majority of cortisol present in the fetal circulation appears to be of maternal origin, at least in the nonhuman primate. The fetal adrenal uses the large amounts of progesterone supplied by th...

The inflammatory cytokines, tumor necrosis factor-alpha, interleukin-1 alpha and -beta (IL-1 alpha and -beta), and IL-6 can activate the hypothalamic-pituitary-adrenal (HPA) axis. Tumor necrosis factor-alpha and IL-1 have been tested in both experimental animals and humans, but their administration has been limited by significant toxicity, mainly severe hypotension. IL-6, on the other hand, has demonstrated modest toxicity in animals. We evaluated the ability of recombinant IL-6 to stimulate the human HPA axis in patients with cancer and a good performance status, who received daily morning sc injections of 30 micrograms/kg IL-6 for 7 consecutive days, during the course of a phase I trial. IL-6 caused impressively marked and prolonged elevations of plasma ACTH and cortisol on the first day and blunted ACTH responses on the seventh day of treatment, perhaps as a result of increased baseline cortisol levels. The overall cortisol response, however, on the seventh day was of similar magnitude, suggesting that a new equilibrium in the feedback regulation of the HPA axis occurs with chronic IL-6 administration. The toxic effects of IL-6 were modest, suggesting that it might be useful for clinical testing of the HPA axis, as an alternative to the insulin tolerance test.

We recently demonstrated that sc administered interleukin-6 (IL-6) strongly stimulates the human hypothalamic-pituitary-adrenal (HPA) axis, with mild toxicity and no hypotensive effects. In this study, we evaluated the response of the human HPA axis to escalating iv doses of recombinant IL-6 in six patients with cancer and good performance status who received daily, every 8 h, three equal doses of 0.3-30 micrograms/kg IL-6. The plasma levels of IL-6 assayed by a specific enzyme-linked immunosorbent assay during the 4 h following the first IL-6 injection were elevated for 2-4 h, proportionally to the amount of injected IL-6. Administration of the cytokine was followed by marked elevations of plasma ACTH (53.0-98.6 pmol/L) and cortisol (824.9-1729.9 nmol/L) independently of the IL-6 dose administered, suggesting that the doses employed were at the top of the dose-response curve for these hormones. Interestingly, plasma arginine vasopressin (AVP) levels were also elevated during the 2 h after IL-6 injection in all patients who received a dose of 3 micrograms/kg or more, suggesting that IL-6 activated the magnocellular AVP-secreting neurons and that it might be involved in the syndrome of inappropriate AVP secretion. Cortisol elevations with peaks similar to those observed after the first injection of IL-6 were also detected in plasma sampled every 2 h after the second and third injections, suggesting that there was no rapid tachyphylaxis in response to IL-6 administration. Plasma IL-1 beta and tumor necrosis factor-alpha concentrations, assayed by specific enzyme-linked immunosorbent assays during the 4 h after the first IL-6 injection, were either within the normal range or undetectable, confirming in vitro observations that IL-6 does not stimulate IL-1 beta or tumor necrosis factor-alpha secretion and suggesting that it exerts its effect on the HPA axis and AVP secretion independently of them. We conclude that IL-6 is a potent stimulator of the human HPA axis and a secretagogue of magnocellular AVP secretion, which might be employed as a challenge test of the axis and the magnocellular AVP neuron.

The term intrauterine growth restriction (IUGR) is assigned to newborns with a birth weight and/or birth length below the 10th percentile for their gestational age and whose abdominal circumference is below the 2.5th percentile with pathologic restriction of fetal growth. IUGR is usually due to maternal, fetal, or placental factors. However, many IUGR cases have unknown underlying cause. Recent studies focus on new factors that can influence fetal development and birth outcome like the timing and the type of fetal nutrition, maternal psychosocial stress and personality variables, 11beta-hydroxysteroid dehydrogenase type 2 placental activity, the activity of the neuroendocrine system that mediates the effects of psychosocial stress, and the role of proinflammatory cytokines and of oxidative stress. Data have shown that IUGR is associated with a late life increased prevalence of metabolic syndrome, a condition associating obesity with hypertension, type 2 diabetes mellitus (DM2), and cardiovascular disease. Recent data demonstrated that the diabetes-associated mortality appears to be disproportionately concentrated among individuals of abnormal birth weight.

Abstract.Carbohydrate and lipid metabolism was cross-sectionally assessed in 16 patients with endogenous hypercortisolism (endogenous Cushing syndrome). Five patients (31%) had fasting glucose levels over 6.6 mmol/l and a HbAic over 7.5%. Six patients (38%) had diabetes mellitus based on an abnormal 75 g oral glucose tolerance test (OGTT) and two additional patients (13%) had impaired glucose tolerance based on an OGTT. Compared to obese individuals, patients with Cushing syndrome had an elevated glucose but no elevated insulin response to the OGTT. Regression analysis showed positive correlations between 24-h urinary free cortisol (UFC) and fasting blood glucose (P<0.0005), UFC and OGTT glucose area under the curve (AUC) (P<0.01), and UFC and HbAlc (P<0.005). UFC levels were negatively correlated (P<0.05) with OGTT insulin AUC and insulin/glucose ratios. Eleven (69%) patients required anti-hypertensive therapy for blood pressure control. Total cholesterol and triglycerides were elevated in patients with Cushing syndrome compared to obese controls, while LDL and HDL cholesterol, and Lp(a) were similar in the two groups. We conclude that impaired glucose tolerance and/or diabetes in patients with endogenous Cushing syndrome is due to the hyperglycemic effects of cortisol with relative insulinopenia.Thus, Cushing syndrome shares features with both the Metabolic Syndrome X and NIDDM, including impaired glucose uptake, hyperlipidemia and hypertension.However, in Cushing syndrome, a relative insulinopenia occurs, while in Metabolic Syndrome X and NIDDM, insulin excess is observed. In Cushing syndrome, as the hypercortisolemia exacerbates, insulinopenia becomes more paramount, suggesting that cortisol exerts a direct or indirect "toxic" effect on the fl -cell .

Background: Throughout pregnancy maternal adipose tissue is metabolically active, producing adipocytokines involved in the process of insulin resistance. We explored the role of serum adipocytokines, including the newly identified adipocytokine visfatin, in the process of insulin resistance in normal pregnancy. Methods: We examined 80 pregnant nonobese, nondiabetic white women during the 3 trimesters of pregnancy. All study participants underwent anthropometric measurements, adipocytokine evaluation, and a 75-g oral glucose tolerance test. Homeostasis mathematical model assessment (HOMA-R), insulin sensitivity index (ISI), and indices of ␤-cell secretion were calculated. Results: Maternal weight, percentage total body fat, hip circumference, and indices of ␤-cell secretion increased significantly during the 3 trimesters, and HOMA-R and ISI increased and decreased, respectively, in the 3rd trimester. During early pregnancy, insulin resistance, ␤-cell secretion, and weight correlated positively with leptin. During the 1st trimester, visfatin correlated negatively with percentage

Objective: Leptin and adiponectin are two adipocytokines that play a critical role in the control of energy balance and metabolism as well as in conditions, such as insulin resistance, inflammation, and the development of the metabolic syndrome in adult life. Leptin has been associated with asymmetric intrauterine growth restriction (IUGR). The aim of this study was to investigate the perinatal implication of leptin and adiponectin in IUGR. Design: Leptin and adiponectin were measured in the plasma of 40 mothers, in the umbilical cord (UC) blood of their 20 appropriate for gestational age (AGA) and 20 IUGR singleton, full-term fetuses, and neonates on day 1 (d1) and day 4 (d4) of life postnatally. Methods: Serum leptin and adiponectin levels were measured by RIA. Serum cortisol levels were measured with an electrochemiluminescence immunoassay. Results: Leptin and adiponectin serum levels were higher and lower respectively in IUGR (meanGS.E.M., 32.5G3.8 and 5.4G0.9 mg/l respectively) compared with AGA (20.4G2.1 and 11.8G1.3 mg/l respectively) mothers (P!0.05), although body mass index did not differ between these two groups. Leptin levels positively correlated with adiponectin levels in the AGA (rZ0.547, P!0.05) but not in the IUGR mothers. UC, d1, and d4 leptin and adiponectin levels did not differ between IUGR and AGA groups. UC were significantly higher than d1 leptin levels (P!0.05) in the IUGR group but not in the AGA group. Conclusions: The increased UC leptin levels compared with d1 in IUGR fetuses might be directly and/or indirectly related to the subsequent development of insulin resistance in these neonates. This pathologic situation seems to be related to a specific profile of increased leptin and decreased adiponectin levels in IUGR mothers indicating a genetic predisposition for the development of insulin resistance.European Journal of Endocrinology 158 343-348

Endometriosis is a common gynecological disorder of the reproductive age characterised by pelvic pain, dysmenorrhea and infertility. Classic theories have failed to propose a precise pathogenetic mechanism. Recent studies have investigated the role of the immune system and oxidative stress in the development of endometriosis as well as the identification of biomarkers for a non-invasive diagnosis of the disease. At endometriotic sites, inflammatory cells including eosinophils, neutrophils and macrophages generate reactive oxygen species that contribute to the development of oxidative stress in the peritoneal cavity. Oxidative stress further augments immune response in affected sites. The oxidants exacerbate the development of endometriosis by inducing chemoattractants and endometrial cell growth-promoting activity. The oxidative proinflammatory state of the peritoneal fluid is an important mediator of endometriosis. Many studies investigate the correlation of endometriosis and oxidative stress but the results are discrepant. Furthermore, oxidative stress has been implicated in unexplained infertility and has been associated with some of its causative factors. Oxidative stress influences women's reproductive capacity. The association between endometriosis and infertility is described in several studies and still remains debated.