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At least 613 records · Page 34Linked to original sources
PubMed2005

Central noradrenergic mechanisms underlying acute stress responses of the Hypothalamo-pituitary-adrenal axis: adaptations through pregnancy and lactation.

Hypothalamo-pituitary-adrenal axis responses to stress are attenuated perinatally, and may contribute towards conservation of energy stores and/or prevention of overexposure to glucocorticoid and its adverse effects in the developing fetus/neonate. Previous work has shown that reduced central drive to the hypothalamo-pituitary-adrenal axis is responsible, since parvocellular paraventricular nucleus neurone responses are reduced. One of the main input pathways to the paraventricular nucleus that is activated by the majority of stressors is the brainstem noradrenergic system. This review outlines key noradrenergic mechanisms that mediate hypothalamo-pituitary-adrenal axis responses to acute stress, and addresses aspects of their adaptation in pregnancy and lactation that can explain the stress hyporesponsiveness at that time. In summary, reduced noradrenaline release and adrenergic receptor expression in the paraventricular nucleus may lead to reduced sensitivity of the hypothalamo-pituitary-adrenal axis to adrenergic antagonists and agonists and its responses to stress. While there are subtle differences in these changes between pregnancy and lactation, it would appear that reduced effectiveness of the noradrenergic input can at least partly account for the reduced hypothalamo-pituitary-adrenal axis responses both pre- and post-natally.

Acute Disease↗
PubMed2006

Perinatal maternal undernutrition programs the offspring hypothalamo-pituitary-adrenal (HPA) axis.

There is now compelling evidence, coming both from animal and human studies that an early exposure to undernutrition is frequently associated with low birth weight and programs HPA axis alterations throughout the lifespan. Although animal models have reported conflicting findings arising from differences in experimental paradigms and species, they have clearly demonstrated that such programming not only affects the brain but also the pituitary corticotrophs and the adrenal cortex. In fetuses, maternal undernutrition reduces HPA axis function and implicates a reduction of placental 11beta-HSD2 activity and a greater transplacental transfer of glucocorticoids (GRs). In young adults, usually only fine HPA axis alterations were observed, whereas in older ones, maternal undernutrition was frequently associated with chronic hyperactivity of this neuroendocrine axis. In humans, evidence of HPA axis dysregulation in people who were small at birth has recently emerged. Thus, we suggest that such alterations in adults may be implicated in the aetiology of several disorders related to the metabolic syndrome as well as to immune or inflammatory diseases. To reverse such programming, recent experimental reports have shown that postnatal environmental interventions, dietary modifications and the use of agents modulating the epigenomic state could partly restore physiological functions and thus open new therapeutic strategies.

Adrenocorticotropic Hormone↗
PubMed2001

Biplane long-axis magnetic resonance imaging. Survey projections for rapid estimation of left ventricular mass and global function.

OBJECTIVE: To evaluate the accuracy and precision of biplane long-axis magnetic resonance imaging (MRI) and two-dimensional (2D)-echocardiography, for the assessment of left ventricular (LV) mass and volumes, with multislice short-axis MRI as reference standard. DESIGN: Forty-five cardiac patients and four volunteers with varying LV dilatation and hypertrophy were examined by biplane long-axis gradient-echo MRI, 2D-echocardiography, and multiple short-axis gradient-echo MRI. RESULTS: Compared with multislice MRI, the accuracy, i.e. the coefficient of variation (c.v.) of inter-method differences of measured variables, was median 15.7% for biplane MRI and 18.5% for 2D-echocardiography. The precision, expressed as the c.v. of repeated measurements, was median 8.5% for multislice MRI, 9.5% for biplane MRI and 12.4% for 2D-echocardiography. For the determination of LV mass index, MRI was significantly more precise (c.v.: 6.0-8.4%) than 2D-echocardiography (c.v.: 13.7-14.3%, p < 0.05). CONCLUSION: Biplane long-axis MRI is a fast and simplified method, offering the advantage of displaying anatomy and function in recognizable projections. For the estimation of LV mass and volumes, biplane MRI had an acceptable accuracy, and a precision that did not differ significantly from that of multislice MRI.

Aged↗
PubMed2006

Direction of spin axis and spin rate of the pitched baseball.

In this study, we aimed to determine the direction of the spin axis and the spin rate of pitched baseballs and to estimate the associated aerodynamic forces. In addition, the effects of the spin axis direction and spin rate on the trajectory of a pitched baseball were evaluated. The trajectories of baseballs pitched by both a pitcher and a pitching machine were recorded using four synchronized video cameras (60 Hz) and were analyzed using direct linear transform (DLT) procedures. A polynomial function using the least squares method was used to derive the time-displacement relationship of the ball coordinates during flight for each pitch. The baseball was filmed immediately after ball release using a high-speed video camera (250 Hz), and the direction of the spin axis and the spin rate (omega) were calculated based on the positional changes of the marks on the ball. The lift coefficient was correlated closely with omegasinalpha (r = 0.860), where alpha is the angle between the spin axis and the pitching direction. The term omegasinalpha represents the vertical component of the velocity vector. The lift force, which is a result of the Magnus effect occurring because of the rotation of the ball, acts perpendicularly to the axis of rotation. The Magnus effect was found to be greatest when the angular and translational velocity vectors were perpendicular to each other, and the break of the pitched baseball became smaller as the angle between these vectors approached 0 degrees. Balls delivered from a pitching machine broke more than actual pitcher's balls. It is necessary to consider the differences when we use pitching machines in batting practice.

Acceleration↗
PubMed2000

Requirement for beta-catenin in anterior-posterior axis formation in mice.

The anterior-posterior axis of the mouse embryo is defined before formation of the primitive streak, and axis specification and subsequent anterior development involves signaling from both embryonic ectoderm and visceral endoderm. Tauhe Wnt signaling pathway is essential for various developmental processes, but a role in anterior-posterior axis formation in the mouse has not been previously established. Beta-catenin is a central player in the Wnt pathway and in cadherin-mediated cell adhesion. We generated beta-catenin-deficient mouse embryos and observed a defect in anterior-posterior axis formation at embryonic day 5.5, as visualized by the absence of Hex and Hesx1 and the mislocation of cerberus-like and Lim1 expression. Subsequently, no mesoderm and head structures are generated. Intercellular adhesion is maintained since plakoglobin substitutes for beta-catenin. Our data demonstrate that beta-catenin function is essential in anterior-posterior axis formation in the mouse, and experiments with chimeric embryos show that this function is required in the embryonic ectoderm.

Animals↗
PubMed1999

Characterization and mutation analysis of human LEFTY A and LEFTY B, homologues of murine genes implicated in left-right axis development.

Members of the transforming growth factor (TGF)-beta family of cell-signaling molecules have been implicated recently in mammalian left-right (LR) axis development, the process by which vertebrates lateralize unpaired organs (e.g., heart, stomach, and spleen). Two family members, Lefty1 and Lefty2, are expressed exclusively on the left side of the mouse embryo by 8.0 days post coitum. This asymmetry is lost or reversed in two murine models of abnormal LR-axis specification, inversus viscerum (iv) and inversion of embryonic turning (inv). Furthermore, mice homozygous for a Lefty1 null allele manifest LR malformations and misexpress Lefty2. We hypothesized that Lefty mutations may be associated with human LR-axis malformations. We now report characterization of two Lefty homologues, LEFTY A and LEFTY B, separated by approximately 50 kb on chromosome 1q42. Each comprises four exons spliced at identical positions. LEFTY A is identical to ebaf, a cDNA previously identified in a search for genes expressed in human endometrium. The deduced amino acid sequences of LEFTY A and LEFTY B are more similar to each other than to Lefty1 or Lefty2. Analysis of 126 human cases of LR-axis malformations showed one nonsense and one missense mutation in LEFTY A. Both mutations lie in the cysteine-knot region of the protein LEFTY A, and the phenotype of affected individuals is very similar to that typically seen in Lefty1-/- mice with LR-axis malformations.

Amino Acid Sequence↗
PubMed2001

A hierarchical axis of object processing stages in the human visual cortex.

How are objects represented in the human visual cortex? Two conflicting theories suggest either a holistic representation, in which objects are represented by a collection of object templates, or a part-based representation, in which objects are represented as collections of features or object parts. We studied this question using a gradual object-scrambling paradigm in which pictures of objects (faces and cars) were broken in a stepwise manner into an increasing number of blocks. Our results reveal a hierarchical axis oriented anterior--posteriorly in the organization of ventral object-areas. Along this axis, representations are arranged in bands of increasing sensitivity to image scrambling. The axis starts in early visual areas through retinotopic areas V4/V8 and continues into the lateral-occipital sulcus dorsally and the posterior fusiform girus ventrally, corresponding together to the previously described object-related lateral occipital complex (LOC). Regions showing the highest sensitivity to scrambling tended to be located at the most anterior-lateral regions of the complex. In these more anterior regions, breaking the images into 16 parts produced a significant reduction in activation. Interestingly, activation was not affected when images were cut in two halves, either horizontally or vertically. Car images generally produced a weaker activation compared to faces in the lateral occipital complex but showed the same tendency of increased scrambling sensitivity along the anterior--posterior axis. These results suggest the existence of a hierarchical axis along ventral occipito-temporal object-areas, in which the neuronal properties shift from sensitivity to local object features to a more global and holistic representation.

Adult↗
PubMed2002

Investigation of suppression of the hypothalamic-pituitary-gonadal axis to restore spermatogenesis in azoospermic men treated for childhood cancer.

BACKGROUND: Does suppression of the hypothalamic-pituitary-gonadal (HPG) axis restore spermatogenesis in men rendered azoospermic following treatment of childhood cancer? METHODS: Seven men with azoospermia secondary to treatment for childhood cancer, median age (range), 22.2 (18-25.3) years, aged 10.4 (4.4-13.3) years at original diagnosis, participated. Each subject underwent semen analysis and testicular biopsy, followed by treatment with medroxyprogesterone acetate (MPA), 300 mg i.m. repeated after 12 weeks, with 800 mg testosterone pellets s.c. on day 1 to suppress the HPG axis. Hormone and semen analysis was performed every 6 weeks for 48 weeks. A second testicular biopsy was performed at week 48. RESULTS: Before HPG axis suppression, mean +/- SEM plasma LH was 9.0 +/- 1.8 U/l, testosterone 17.9 +/- 1.5 nmol/l and FSH 22.4 +/- 4.4 U/l. Median (range) venous plasma and seminal plasma inhibin B levels were 10.0 (7.8-35) and 11.2 (7.8-770) ng/l respectively. During HPG suppression, FSH and LH levels were undetectable for > or =12 weeks followed by a gradual return to pretreatment concentrations by 48 weeks. All men remained azoospermic at study completion and complete absence of germ cells on biopsies was demonstrated by immunocytochemistry for all specimens pre- and post-HPG axis suppression. CONCLUSIONS: HPG axis suppression with MPA-testosterone for > or =12 weeks did not restore spermatogenesis in azoospermic men treated with gonadotoxic radiotherapy and chemotherapy for childhood cancer.

Adolescent↗
PubMed2005

Daily and photoperiod variations of hypothalamic-pituitary-adrenal axis responsiveness in Japanese quail selected for short or long tonic immobility.

The aims of this study were to investigate the existence of a circadian rhythm of basal corticosterone (B) plasma concentrations in male and female Japanese quail lines divergently selected for long (LTI) or short (STI) duration of tonic immobility (TI) and the possible effects of photoperiod length on corticotropic axis reactivity. Significant peaks in B levels were observed throughout the day in 3 out of the 4 groups used in our experiments. However, B levels remained very low for all groups (< 5.0 ng/mL) and there was no consensus between groups. We therefore have no evidence from our results that basal B levels follow a circadian rhythm in adult STI and LTI quail held under a long photoperiod (16L:8D). We also showed that rearing under a long photoperiod (16L:8D) was associated with higher basal B levels and higher B adrenal response capacity to 1-24 adrenocorticotropic hormone (ACTH) injection in the STI and LTI lines compared with a shorter period (8L:16D). Higher hypothalamic-pituitary-adrenal (HPA) axis responsiveness to restraint in a crush cage was also measured in female quail reared under the long photoperiod, and similar responses were measured under both photoperiods in males. This result suggests that the effects of photoperiod length involve both local and more central mechanisms in the control of HPA axis responsiveness according to sex. On the other hand, we showed that the genetic selection program for TI responses induced greater increases in the B level following restraint in STI quail than in LTI quail of both sexes under both photoperiods, but the B adrenal response capacity was similar for both lines and sexes. Although further investigations on both lines regarding adrenal sensitivity are necessary before being able to conclude definitively, our findings strongly suggest that the differences observed in HPA axis responsiveness to restraint between lines are probably not due to differences in adrenal function itself but may involve upstream structures of the HPA axis.

Aging↗
PubMed1987

Axis for dynamic measurement of flexion and extension torques about the lumbar spine. A computer simulation.

Most reports of trunk testing with an isokinetic dynamometer describe the axis of the machine aligned with the lumbosacral junction. A computerized mathematical simulation of motion of the lumbar spine under three conditions was performed, representing variations on the physiologic motion of the lumbar spine. The instantaneous center of rotation of the T12 vertebral body moving about a fixed pelvis was calculated and displayed. Under normal conditions, the center of rotation started close to the center of the L3 vertebral body and moved in an arc similar to that of L3 during flexion and extension. Dynamic testing of the trunk musculature in the lumbar region, therefore, should be performed with the axis of the isokinetic dynamometer aligned with the L3 vertebral body, and motion of the pelvis and thoracic spine should be minimized. This position of the axis provides the best approximation of the fixed axis of the testing machine to the physiologic axis. Failure to observe these precautions would tend to make the motion of the lumbar spine nonisokinetic and, thus, interfere with angular measurement of the spinal motion.

Adult↗
PubMed2002

Impact of maternal undernutrition during the periconceptional period, fetal number, and fetal sex on the development of the hypothalamo-pituitary adrenal axis in sheep during late gestation.

Evidence from epidemiologic, clinical, and experimental studies has shown that a suboptimal intrauterine environment during early pregnancy can alter fetal growth and gestation length and is associated with an increased prevalence of adult hypertension and cardiovascular disease. It has been postulated that maternal nutrient restriction may act to reprogram the development of the pituitary-adrenal axis, resulting in excess glucocorticoid exposure and adverse health outcomes in later life. It is unknown, however, whether maternal nutrient restriction during the periconceptional period alters the development of the fetal pituitary-adrenal axis or whether the effects of periconceptional undernutrition can be reversed by the provision of an adequate level of maternal nutrition throughout the remainder of pregnancy. We have investigated the effect of restricted periconceptional nutrition (70% of control feed allowance) from 60 days before until 7 days after mating and the effect of restricted gestational nutrition from Day 8 to 147 of gestation on the development of the fetal hypothalamo-pituitary adrenal (HPA) axis in the sheep. In these studies, we have also investigated the effects of fetal number and sex on the pituitary-adrenal responses to periconceptional and gestational undernutrition. In ewes maintained on a control diet throughout the periconceptional and gestational periods, fetal plasma ACTH concentrations were higher and the prepartum surge in cortisol occurred earlier in singletons compared with twins. Plasma ACTH concentrations were also significantly higher in male compared with female singletons, and in twin fetuses, the prepartum surge in cortisol concentrations occurred earlier in males than in females. Periconceptional undernutrition resulted in higher fetal plasma concentrations of ACTH between 110 and 145 days of gestation and a significantly greater cortisol response to a bolus dose of corticotropin-releasing hormone in twin, but not singleton, fetuses in late gestation. We have therefore demonstrated that fetal number and sex each has an impact on the timing of the prepartum activation of the HPA axis in the sheep. Restriction of the level of maternal nutrition before and in the first week of a twin pregnancy results in stimulation of the fetal pituitary-adrenal axis in late gestation, and this effect is not reversed by the provision of a maintenance control diet from the second week of pregnancy.

Adrenocorticotropic Hormone↗
PubMed1998

Mechanisms mediating the influence of alcohol on the hypothalamic-pituitary-adrenal axis responses to immune and nonimmune signals.

In the rat, the acute administration of alcohol induces dose-related increases in plasma ACTH and corticosterone levels. This response depends on the delivery of the hypothalamic peptides corticotropin-releasing factor and vasopressin (VP) to the pituitary. On the other hand, exposure to an alcohol diet for 7 to 10 days significantly blunts the hypothalamic-pituitary-adrenal (HPA) axis in response to other homeostatic threats, such as mild electroshocks or immune signals. This decreased response is at least in part due to an attenuated ability of VP to increase ACTH secretion. We have previously shown that nitric oxide (NO) inhibits the pituitary response to VP. We therefore hypothesized that chronic alcohol treatment might increase levels of this gas within the HPA axis, and tested this possibility by determining whether blockade of NO formation might restore a normal pituitary response to VP. We observed that such was the case, and therefore propose that NO participates in the blunted activity of the HPA axis during prolonged exposure to alcohol. Finally, we determined whether alcohol would exert neuroendocrine effects that extended beyond the initial drug treatment. To explore this possibility, we injected rats with alcohol intragastrically for 3 days, then re-exposed them to the drug 3 to 12 days later. Rats pretreated with the vehicle and injected with alcohol several days later showed the expected significant rise in plasma ACTH and corticosterone levels, as well as a marked increase in immediate early genes mRNA levels in the paraventricular nucleus (PVN) of their hypothalamus. In contrast, animals pretreated with alcohol exhibited a blunted hormonal and hypothalamic response during the second drug exposure but, interestingly, retained a normal endocrine response to other signals, such as exposure to electro-footshocks or cytokine injection. We originally thought that this phenomenon of selective endocrine tolerance might be explained by decreased serotonin levels in the PVN. Whereas alcohol indeed decreased concentrations of this neurotransmitter in the PVN, exposure to electroshocks induced similar changes. However, an initial exposure to shocks did not blunt the ability of the HPA axis to be activated by a second shock session, by alcohol or by immune signals (delivered several days later). These results do not support the hypothesis that the decreased HPA axis response to a second alcohol challenge is mediated via decreased serotonin afferents to corticotropin-releasing factor neurons in the PVN.

Adrenocorticotropic Hormone↗
PubMed2000

Axis location of tibial rotation and its change with flexion angle.

The magnitude and location of the axis of tibial rotation were measured at 15 degrees increments between 0 degree and 90 degrees flexion using 24 normal anatomic knee specimens, and their changes with flexion angle were investigated. The magnitude of tibial rotation was small (8.3 degrees) at 0 degree flexion, but increased rapidly as the flexion angle increased and reached a maximum rotation (31.7 degrees) at 30 degrees flexion. It then decreased again with additional flexion (24.8 degrees at 90 degrees flexion). The location of the axis was close to the tibial insertion of the anterior cruciate ligament at 0 degree flexion, gradually moving toward insertion of the posterior cruciate ligament (observed at 45 degrees and 60 degrees flexion), and then moved anteriorly again with additional flexion: the axis was approximately equidistant from the two cruciate insertions at 90 degrees flexion. The results showed that a relatively large degree of tibial rotation was possible in a normal knee and that the location of the axis remained approximately in the area between the two cruciate ligament insertions throughout the range of flexion. However, the location of the axis changed with the flexion angle within this area according to the changes in direction and tension of the cruciate ligaments and the surrounding soft tissues.

Adult↗
PubMed1995

Installation of 60Co 100 cm source-to-axis distance teletherapy units in vaults designed for 80-cm units.

60Co teletherapy units featuring 100 cm source-to-axis distances and with nominal source activities of 481 TBq (13,000 Ci) are available as replacements for older model 80 cm source-to-axis teletherapy units that generally have source activities of less than 370 TBq (10,000 Ci). We have redesigned and renovated two vaults--one of which required supplemental shielding--designed for older 80 cm source-to-axis units with 333 TBq (9,000 Ci) sources and installed modern 100 cm source-to-axis units with 481 TBq (13,000 Ci) sources. Renovation costs (in 1991 U.S. dollars) were about $40,000 and $160,000; the latter, including shielding costs, was about two-thirds of projected costs for installation of a 6 MV electron beam linear accelerator (linac). We have designed the treatment heads of these 100 cm 60Co units to accept the secondary field shaping blocks used on 100 cm source-to-axis linacs, allowing the 60Co units to be used as emergency back-up units for linacs when they are inoperable.

Cobalt Radioisotopes↗
PubMed1997

Cardiac axis change between prone and supine positioning may contribute to differences in 99Tc(m)-MIBI myocardial SPET imaging.

The aims of this study were to assess the effect of prone and supine positioning on 99Tc(m)-MIBI myocardial SPET images and the contribution of cardiac axis change. We compared 227 tomograms of patients imaged in the prone position with 227 tomograms of the same patients imaged in the supine position. For each tomographic session, the axis angle of the heart was recorded using an in-house program. The results showed a significant change in the cardiac axis angle of 9 degrees in the transaxial plane (P < 0.001). This change in the cardiac axis correlated with differences in cardiac wall activity (wall activity when the patient was imaged in the prone position minus wall activity when the patient was imaged in the supine position). Our results suggest that factors other than diaphragmatic movement and attenuation could account for the differences in wall activity observed when patients are imaged prone versus supine. Differences in the intensity of photon attenuation in the heart itself, depending on the cardiac axis, could be a contributing factor. Quantitation of the variation in wall activity leads us to suggest that 99Tc(m)-MIBI SPET should be performed in the prone position to allow better visualization of the inferior and the septal walls. The anterior and lateral walls are better studied in the supine position. Images acquired in both the prone and supine positions would allow the best assessment of all walls.

Coronary Disease↗
PubMedDate not supplied

Growth hormone and insulin-like growth factor I axis and growth of children with different sickle cell anemia haplotypes.

BACKGROUND: The purpose of this study was to examine the relationships between growth in children with sickle cell anemia and the different beta-globin haplotypes, as well as components of the insulin-like growth factor (IGF)/insulin-like growth factor binding protein (IGFBP) axis. PATIENTS AND METHODS: Growth parameters and plasma concentrations of growth hormone (GH), IGF-I, and IGFBP-3 were studied in 41 children with sickle cell anemia whose haplotypes were defined. RESULTS: Plasma concentrations of IGF-I (total, free, and free/total fraction) and IGFBP-3 were significantly reduced in all patients with sickle cell anemia compared with the healthy children. Patients with the CAR/CAR haplotype had significantly lower mean growth velocity compared with those with Ben/Ben. When the GH/IGF axis elements were compared in relation with the different haplotypes, total IGF-I levels in CAR/CAR patients were significantly lower compared with levels in patients with Ben/Ben. A positive correlation was found between hematocrit and total IGF-I and between fetal hemoglobin percentages and the z-scores for total IGF-I and IGFBP-3. There was a positive correlation between age, weight, height, bone age, and the various elements of the GH/IGF-I axis when all groups were considered, although the correlation was lost when the auxologic data were expressed as standard deviation score for age. Growth velocity and the z-score for growth velocity were not correlated with any element of the axis. CONCLUSIONS: The positive relationship between hematocrit and fetal hemoglobin percentages with total IGF-I, free/total IGF-I, and IGFBP-3 in patients with sickle cell anemia could show that the delayed growth of these patients may be linked to intrinsic factors of the disease, which also determine the low circulating concentrations of the various elements of the GH/IGF-I axis. It is reasonable to assume that decrease of total IGF-I concentrations in patients with CAR/CAR haplotype is secondary to the severity of the disease.

Adolescent↗
PubMed2003

Effect of chronic alcohol consumption on the activity of the hypothalamic-pituitary-adrenal axis and pituitary beta-endorphin as a function of alcohol intake, age, and gender.

BACKGROUND: Experimental evidence indicates that components of the hypothalamic-pituitary-adrenal (HPA) axis and of the endogenous opioid system, such as beta-endorphin (beta-END), influence alcohol consumption, whereas chronic alcohol abuse alters the activity of both systems. Furthermore, gender and age differences have been reported in the activity of the HPA axis under basal conditions, in response to stress and acute alcohol challenge. The objective of the present studies was to investigate the hypothesis that chronic alcohol consumption alters the activity of the HPA axis and pituitary beta-END as a function of severity of alcohol abuse, gender, and age. METHODS: Three age groups of each gender (18-29, 30-44, and 45-60 years old) were recruited. Each age and gender group included four subgroups: (a) nondrinkers, (b) light drinkers, (c) heavy drinkers, and (d) alcoholics in treatment. Demographic characteristics, alcohol consumption, and presence of alcohol dependence were recorded by using a structured interview. Blood samples were taken on the day of the interview. The levels of plasma adrenal corticotropic hormone (ACTH), cortisol, and beta-END were estimated as an index of the activity of the HPA-axis and pituitary beta-END. RESULTS: Plasma ACTH and beta-END levels were significantly lower in females than males of all age and drinking category groups. Plasma cortisol levels were higher in 18- to 29-year-old female subjects compared with the 18- to 29-year-old male subjects. The plasma ACTH and beta-END levels were lower whereas plasma cortisol levels were higher in heavy drinkers than nondrinkers. This decrease in plasma ACTH and beta-END levels with heavy drinking was more pronounced in female than male subjects of the 30-44 and 45-60 age groups. CONCLUSIONS: Chronic drinking, gender, and age influence the activity of the HPA-axis and pituitary beta-END, which in turn may influence drinking behavior.

Adolescent↗
PubMed2004

Early experience and sex interact to influence limbic-hypothalamic-pituitary-adrenal-axis function after acute alcohol administration in rhesus macaques (Macaca mulatta).

BACKGROUND: Studies in rodents demonstrate sex differences in neuroendocrine stress axis activity after treatment with alcohol. In abstinent alcoholics, atypical depressives, and individuals with posttraumatic stress disorder, limbic-hypothalamic-pituitary-adrenal (LHPA)-axis activity is often blunted; among females in these patient populations, however, resistance to glucocorticoid feedback and increased pituitary reactivity is observed. Early parental loss is a major life stressor and is a risk factor for both affective disturbances and LHPA-axis abnormalities later in life. We wanted to determine whether sex and early life parental absence would interact to influence alcohol-induced alterations in LHPA-axis activity after exposure to ethanol in macaques. METHODS: Animals were reared with their mothers in social groups (MR, n = 94) or without adults in peer-only groups (PR, n = 79). At 5 years of age, they received an intravenous infusion of alcohol (2-2.2 g/kg), and the effects of alcohol, sex, and rearing condition on ACTH and cortisol levels were analyzed by ANOVA. RESULTS: Peer-reared females had higher ACTH levels than did PR males, MR females, and MR males after alcohol infusion. Alcohol-induced cortisol levels were not affected by sex and rearing condition. CONCLUSIONS: These findings suggest that there are sex differences in glucocorticoid negative feedback, pituitary responsivity, or release of ACTH secretagogues among individuals exposed to early life stress and emphasize the importance of considering sex effects when studying LHPA-axis dysregulation in alcoholism and other stress-related neuropsychiatric disorders.

Animals↗