Search results for "Endocrine Gland"
showing 10 items of 142 documents
The role of arginine-vasopressin for pineal melatonin synthesis in the rat: involvement of vasopressinergic receptors.
1991
Abstract The endogenously synthesized nonapeptide arginine vasopressin (AVP) is thought to be involved in transduction of photic information to the pineal gland. The enhancement of circulating AVP leads to a suppression of the nocturnal melatonin surge the mechanisms of which are unknown so far. We therefore studied the effect of dDAVP, an AVP analog with antidiuretic but without vasopressor activity, on pineal melatonin synthesis in Sprague-Dawley and AVP-deficient Brattleboro rats. The nocturnal intra-arterial application of dDAVP mimicked the inhibitory effect of AVP on the activity of the rate-limiting enzyme for pineal melatonin synthesis, N-acetyltransferase (NAT), in both rat strains…
Immunohistochemical analysis of chromogranin A and multiple peptides in the mammalian Merkel cell: further evidence for its paraneuronal function?
1989
By the use of light microscopic immunohistochemistry, epidermal Merkel cells have been examined for the coexistence of some neuropeptides and chromogranin A (CGA). Peptide and CGA-immunophenotypes were similar in adult Merkel cells but variable in fetal skin, where CGA preceded the expression of peptides which were partly expressed only in a subpopulation of Merkel cells from hair follicles. Thus, only Substance P (SP) and calcitonin gene-related peptide (CGRP) were expressed in a subpopulation of Merkel cells from hair follicles. There were similar Merkel cell densities visualized on consecutive paraffin sections by the use of antisera against peptides, CGA and cytokeratin offering useful …
Prognostic Impact of Hyponatremia and Hypernatremia in COVID-19 Pneumonia. A HOPE-COVID-19 (Health Outcome Predictive Evaluation for COVID-19) Regist…
2020
Dysnatremia is associated with increased mortality in patients with community-acquired pneumonia. SARS-COV2 (Severe-acute-respiratory syndrome caused by Coronavirus-type 2) pneumonia can be fatal. The aim of this study was to ascertain whether admittance dysnatremia is associated with mortality, sepsis, or intensive therapy (IT) in patients hospitalized with SARS-COV2 pneumonia. This is a retrospective study of the HOPE-COVID-19 registry, with data collected from January 1th through April 31th, 2020. We selected all hospitalized adult patients with RT-PCR-confirmed SARS-COV2 pneumonia and a registered admission serum sodium level (SNa). Patients were classified as hyponatremic (SNa <…
Nicotinic cholinoceptors in the rat pineal gland as analyzed by Western blot, light- and electron microscopy
1992
Abstract The monoclonal antibody WF6, raised against purified Torpedo nicotinic acetylcholine receptor (nAChR) was used to study the distribution of cholinoceptors in the rat pineal gland by means of Western blot analysis, light- and electron microscopy. The immunoblot analysis using homogenized pineal gland revealed a labeled protein band of apparent molecular weight 40 kDa which was identified as α-subunits of a nAChR. In the light microscope, approximately one-fourth of the pinealocytes exhibited cytoplasmic immunoreactivity (IR) of varying density. In the electron microscope, IR was seen as patchy staining of cell membranes of pinealocyte somata and processes. Presynaptic IR material wa…
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…
Glycemic Dysregulations Are Associated With Worsening Cognitive Function in Older Participants at High Risk of Cardiovascular Disease: Two-Year Follo…
2021
The authors wish to thank the PREDIMED-Plus participants and staff for their engagement, as well as to the primary care centers involved in the study. We also thank the Cerca Programme of the Generalitat de Catalunya, and the CIBEROBN, CIBERESP and CIBERDEM initiatives of Instituto de Salud Carlos III in Spain, and the collaborators in the PRIME consortium for helpful input. The first version of the present article has been published in the public repository Research Square as a preprint publication of our work (44). We particularly thank Stephanie Nishi for her assistance with manuscript language revision.
Down-regulation of the nocturnally elevated guanylyl cyclase activity in the rat pineal gland
1995
Abstract Previous studies have shown that in the rat pineal, the cytosolic and the particulate forms of guanylyl cyclase (GC) activity undergo a biphasic 24-h rhythm with two prominent peaks, one in the middle of the light phase and the other in the middle of the dark phase. In this study we investigated whether the well established photo-neural adrenergic regulatory processes identified for pineal melatonin synthesis also apply to the nocturnal elevation of GC activity. A 10-min light pulse given in the middle of the dark phase decreases the cytosolic and the particulate forms of GC. Administration of the β-receptor blocker propranolol did not depress the nocturnally elevated GC activity. …
Day-night rhythm of acetylcholine in the rat pineal gland
1997
Abstract Using high-performance-liquid-chromatography (HPLC) measurement of acetylcholine, choline acetyltransferase (ChAT) enzyme assay and anti-ChAT immunohistochemistry, we have investigated the expression of the cholinergic system in pineal glands of male rats. Glands procured during the day period (1200 h) contained significant amounts of acetylcholine (0.5 pmol/gland). A similar content was found in pineal glands after a 48 h culture period, i.e. when the intrapineal nerve fibres have degenerated. This strongly indicates that the pinealocytes are the cells which contain acetylcholine. To confirm this conclusion we demonstrate substantial ChAT-like immunoreactivity in pinealocytes. ChA…
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…