Search results for "pituitary"
showing 10 items of 238 documents
Cortisol awakening response and cognitive performance in hypertensive and normotensive older people.
2016
Healthy older people with a cortisol awakening response (CAR) of decreased magnitude show worse frontal cortex-related cognitive performance. Systemic hypertension has been related to a CAR of decreased magnitude. Additionally, worse executive function and processing speed have been observed in older people with systemic hypertension. This is the first study to examine the relationship between the CAR (measured with six saliva samples at home on two consecutive weekdays) and cognitive performance, in both hypertensive (n=26) and normotensive (n=28) older people (from 56 to 78years old). Hypertensive participants showed lower morning cortisol secretion, and they also woke up earlier. No diff…
The cortisol awakening response and memory performance in older men and women.
2012
Summary The activity and regulation of the hypothalamus-pituitary-adrenal axis has been related to cognitive decline during aging. This study investigated whether the cortisol awakening response (CAR) is related to memory performance among older adults. The sample was composed of 88 participants (44 men and 44 women) from 55 to 77 years old. The memory assessment consisted of two tests measuring declarative memory (a paragraph recall test and a word list learning test) and two tests measuring working memory (a spatial span test and a spatial working memory test). Among those participants who showed the CAR on two consecutive days, we found that a greater CAR was related to poorer declarativ…
Chronic psychosocial stress and antidepressant treatment in tree shrews: time-dependent behavioral and endocrine effects.
1999
Abstract Social defeat has been shown to cause a number of behavioral, physiological, and central nervous changes in male tree shrews. The present study was designed to assess: (i) a potential time lag in the occurrence of behavioral alterations (locomotor activity, self-grooming, marking behavior, food and water intake, and avoidance behavior) after stress and long-term antidepressant treatment; and (ii) to investigate potential interactions between behavioral and endocrine variables (urinary cortisol and norepinephrine). Male tree shrews were submitted to chronic psychosocial stress for 39 days. In this paradigm, the stress-induced behavioral and endocrine alterations in subordinate anima…
Correlation between adrenal function, growth hormone secretion, and insulin sensitivity in children with idiopathic growth hormone deficiency
2017
Purpose Patients with growth hormone deficiency (GHD) demonstrate an increased cortisol/cortisone ratio which could potentially explain the metabolic features of GHD, while GH treatment (GHT) could increase the cortisol metabolism. Methods In 35 children (27 M, mean age 10.1 years) with idiopathic GHD at baseline and after 12 months of GHT and in 25 controls, in addition to metabolic parameters, we assessed adrenal function by morning serum cortisol, its peak, and its area under the curve (AUCCOR) during insulin tolerance test (ITT). Results A cortisol peak <18 µg/dl was shown in 22 and 31% of GHD children at baseline and after GHT, respectively. At baseline, GHD children had lower fasting …
Chernobyl exposure as stressor during pregnancy and hormone levels in adolescent offspring
2008
Background: Animal research suggests a programming effect of prenatal stress in the fetal period, resulting in disruptions in behavioural and neuromotor development. Physiological changes that mediate these effects include alterations in the hypothalamic-pituitary-adrenal axis and in testosterone levels. This human study focuses on changes related to these physiological systems after prenatal stress exposure. Methods: We examined the potential effect of prenatal stress associated with the Chernobyl disaster in an ongoing genetic epidemiological study in Finland. One birth cohort of twins (n = 121 twin pairs) was exposed in utero to maternal stress, and their saliva cortisol and testosterone…
Uptake of [3H]dopamine into dopaminergic and noradrenergic neurones of the isolated neurointermediate lobe of the rat hypophysis. Effects of desipram…
1983
The isolated neurointermediate lobe (NIL) of the rat hypophysis accumulates [3H]dopamine from the incubation medium. Column chromatographic analysis showed that 92% of the tissue radioactivity was contained in the catecholamine fraction. [3H]Dopamine represented 70% and [3H]noradrenaline 30% of the [3H]catecholamines. Desipramine (1 microM) prevented the formation of [3H]noradrenaline without affecting the storage of [3H]dopamine. Nomifensine (10 microM) blocked the storage of [3H]dopamine and [3H]noradrenaline. Thus, in the NIL, [3H]dopamine is taken up into dopaminergic and noradrenergic neurones. In the latter, [3H]dopamine is converted to [3H]noradrenaline, indicating a significant dopa…
Sequential contrast-enhanced magnetic resonance imaging in the diagnosis of growth hormone deficiencies
1999
The purpose of the present study was to assess the presence and the time-course of contrast-enhancement in the pituitary gland and pituitary stalk of 24 patients with isolated growth hormone (GH) deficiency and multiple pituitary hormone deficiency. The patients were evaluated clinically (auxological measurements), endocrinologically (spontaneous GH secretion and GH stimulation tests) and with conventional MRI scans. In addition, fast-framing dynamic magnetic resonance imaging (MRI) with Gd-DTPA enhancement was used to quantitate the time course of contrast enhancement within the neurohypophysis, pituitary stalk, postero-superior adenohypophysis and antero-inferior adenohypophysis. In 3 pat…
The oxytocin receptor system: structure, function, and regulation.
2001
The neurohypophysial peptide oxytocin (OT) and OT-like hormones facilitate reproduction in all vertebrates at several levels. The major site of OT gene expression is the magnocellular neurons of the hypothalamic paraventricular and supraoptic nuclei. In response to a variety of stimuli such as suckling, parturition, or certain kinds of stress, the processed OT peptide is released from the posterior pituitary into the systemic circulation. Such stimuli also lead to an intranuclear release of OT. Moreover, oxytocinergic neurons display widespread projections throughout the central nervous system. However, OT is also synthesized in peripheral tissues, e.g., uterus, placenta, amnion, corpus lut…
Cell type heterogeneity of intermediate filament expression in epithelia of the human pituitary gland.
1989
In the present study we have localized immunohistochemically the intermediate filament proteins of the human pituitary gland (adenohypophysis, pars intermedia and pars tuberalis) by an indirect immunoperoxidase technique or by double immunofluorescence methods and analysed the individual cytokeratin polypeptides using two-dimensional gel electrophoresis. We found that the expression of cytokeratins in different epithelial cells of the human anterior pituitary gland was heterogeneous. Whereas the endocrine cells only expressed cytokeratins 8 and 18, the folliculo-stellate cells exhibited a reactivity for cytokeratins 7, 8, 18 and 19 as well as for GFAP and vimentin. The squamous epithelial c…
The Adult Pituitary Shows Stem/Progenitor Cell Activation in Response to Injury and Is Capable of Regeneration
2012
The pituitary gland constitutes, together with the hypothalamus, the regulatory core of the endocrine system. Whether the gland is capable of cell regeneration after injury, in particular when suffered at adult age, is unknown. To investigate the adult pituitary's regenerative capacity and the response of its stem/progenitor cell compartment to damage, we constructed a transgenic mouse model to conditionally destroy pituitary cells. GHCre/iDTR mice express diphtheria toxin (DT) receptor after transcriptional activation by Cre recombinase, which is driven by the GH promoter. Treatment with DT for 3 d leads to gradual GH+ (somatotrope) cell obliteration with a final ablation grade of 80–90% 1…