Search results for "Anterior pituitary"
showing 10 items of 14 documents
Optogenetically enhanced pituitary corticotroph cell activity post-stress onset causes rapid organizing effects on behaviour
2016
The anterior pituitary is the major link between nervous and hormonal systems, which allow the brain to generate adequate and flexible behaviour. Here, we address its role in mediating behavioural adjustments that aid in coping with acutely threatening environments. For this we combine optogenetic manipulation of pituitary corticotroph cells in larval zebrafish with newly developed assays for measuring goal-directed actions in very short timescales. Our results reveal modulatory actions of corticotroph cell activity on locomotion, avoidance behaviours and stimulus responsiveness directly after the onset of stress. Altogether, the findings uncover the significance of endocrine pituitary cell…
The neuroendocrinological profile of roxindole, a dopamine autoreceptor agonist, in schizophrenic patients
1995
Roxindole is a potent autoreceptor-selective dopamine agonist with additional properties as a serotonin reuptake inhibitor and 5-HT1A agonist. In order to get more insight into its mode of action in various psychiatric populations, we evaluated the effects of subchronic roxindole treatment on pituitary and adrenal hormone secretion, i.e. release of prolactin, thyroid stimulating hormone (TSH), growth hormone (GH), luteinizing hormone (LH), and cortisol. Fifteen schizophrenic patients with positive and negative symptomatology, respectively, were treated with roxindole for 28 days. Both basal and thyrotropin releasing hormone (TRH) -induced prolactin secretion diminished significantly to 26.4…
Neuroendocrine response to antipsychotics: effects of drug type and gender
1999
Abstract Background: To study the influences of drug type and gender on the neuroendocrine response to neuroleptic treatment, we compared the endocrine actions of two neuroleptics with different receptor affinity profiles—a substituted benzamide, amisulpride, a selective D 2 -like dopamine antagonist; and a thioxanthene, flupenthixol, a mixed D 1 /D 2 -like antagonist also blocking serotonin, H 1 , and D 1 receptors—on anterior pituitary hormone secretion in schizophrenic patients (DSM-III-R). Methods: Blood was withdrawn at 15-min intervals to assess basal secretion of prolactin, growth hormone (GH), and thyroid-stimulating hormone (TSH). Four hundred micrograms of thyrotropin-releasing ho…
Developmental Changes and Daily Rhythm in Melatonin-Induced Inhibition of 3′,5′-Cyclic AMP Accumulation in the Rat Pituitary
1990
Melatonin's transduction mechanisms were investigated using in vitro cultured anterior hemipituitaries. Melatonin inhibited cAMP and 3',5'-cyclic GMP accumulation in neonatal rat anterior pituitary stimulated with LHRH. Maximal inhibitory effect was reached within 25 min and persisted for at least 20 min. Inhibition of cAMP accumulation is specific for melatonin because its analogs N-acetylserotonin and 5-methoxytryptamine are 1000 times less potent. Melatonin effect is age- and time-dependent. Marked inhibition was observed in 5-, 10-, and 14-day-old rats but not in 29-day-old ones. Melatonin was significantly more potent when applied at the end of the light period as compared with the fir…
Metabolic impact of adult-onset, isolated, growth hormone deficiency (AOiGHD) due to destruction of pituitary somatotropes.
2011
Growth hormone (GH) inhibits fat accumulation and promotes protein accretion, therefore the fall in GH observed with weight gain and normal aging may contribute to metabolic dysfunction. To directly test this hypothesis a novel mouse model of adult onset-isolated GH deficiency (AOiGHD) was generated by cross breeding rat GH promoter-driven Cre recombinase mice (Cre) with inducible diphtheria toxin receptor mice (iDTR) and treating adult Cre(+/-), iDTR(+/-) offspring with DT to selectively destroy the somatotrope population of the anterior pituitary gland, leading to a reduction in circulating GH and IGF-I levels. DT-treated Cre(-/-), iDTR(+/-) mice were used as GH-intact controls. AOiGHD im…
Melatonin modulates diacylglycerol and arachidonic acid metabolism in the anterior pituitary of immature rats.
1990
In pituitary glands of immature rats prelabeled in vitro with [3H]arachidonic acid, melatonin diminished the luteinizing hormone-releasing hormone (LHRH)-induced increase in [3H]diacylglycerol accumulation as well as [3H]arachidonic acid release from the tissue. Melatonin reduced also LHRH-stimulated incorporation of [3H]glycerol into pituitary [3H]diacylglycerol. The effect was day-time dependent: in the evening experiment melatonin was effective at 0.1 nM concentration while in the morning it had no effect even at 10 nM concentration. The effect of melatonin was also abolished by pretreatment with pertussis toxin. Diacylglycerol and/or arachidonic acid might serve as 2nd messengers transd…
Das Zellbild der Rattenhypophyse nach kombinierter Verabreichung einiger Thyreostatica zusammen mit SH-gruppenhaltigen Verbindungen unter besonderer …
1954
1. Es werden die Veranderungen des Zellbildes des Hypophysenvorderlappens der Ratte beschrieben, die sich nach Verabreichung thyreostatisch wirkender Stoffe ergeben. Diese Zustande werden mit den Zellbildern verglichen, die durch zusatzliche Gabe SH-gruppenhaltiger Verbindungen zu den gleichen Thyreostatica resultieren. 2. Es zeigte sich, das ein experimentell erzeugtes Wachstum der Glandula thyreoidea unabhangig von der Stoffwechselanderung verlaufen kann. 3. Stoffwechselanderung ist mit einer Alteration derβ-Zellen des Hypophysenvorderlappens verbunden. Dieβ-Zellen sind bei Thyroxinmangel vermehrt. 4. Kropfbildung geht mit einer Zunahme der Stammzellen einher, die vermehrtγ-Zellen bilden.…
Zum Einfluss von Angiotensin II auf die Nebennierenrinde unter chemischer adrenostase mit SU 4885 (Metopiron)
1964
The inhibition of 11-β-hydroxylase in the adrenal cortex with SU 4885 (metopiron) increases the ACTH-secretion. Val5-angiotensin II blocks the reaction of the anterior pituitary gland similarly as does dexamethasone. Mode and intensity of this action of angiotensin II, and the influence on rats treated as described, are studied.
MR IMAGING AND HORMONAL FINDINGS IN PATIENTS WITH IDIOPATHIC GROWTH HORMONU DEFICIENCY
1993
Until the introduction of MR imaging in neuroradiological diagnostic, diagnosis of the ecotopic posterior pituitary lobe, first described by the pathologist Priesel in 1920, was rare. Recently it has increasingly been diagnosed by MR in patients whose anamnesis showed birth trauma. We performed MR of the hypothalamic-pituitary region in 17 patients with idiopathic growth hormone deficiency. 8 patients had additional deficiencies of the anterior pituitary lobe whereas the function of the posterior lobe of the hypophysis was normal in all patients. Indications of birth trauma were present in only 2 patients. The cause of anterior lobe insufficiency was determined by MR in 8 patients with panh…
CHANGES IN ALBINO RAT TESTICLE INTERSTITIAL CELLS AFTER PITUITARY STIMULATION IN VIVO WITH HeNe LASER
1995
Population I Leydig cells of the central part of the Albino rat testicle showed signs of increased but nonspecific activity in the entire series of experimental animals compared with sham irradiated controls (n = 30 in each group) after anterior pituitary stimulation with low incident energy levels of the HeNe laser at 632.8 nm with an incident power at the pituitary calculated as 2.75 ± 0.25 mW. The authors conclude that LLLT applied to the pituitary in the rat model at the parameters used in the present study may have an effect on testosterone production. Further quantitative and qualitative work is required to assess the significance of the increase in activity of type I Leydig cells and…