Search results for "Neurosecretory Systems"
showing 10 items of 24 documents
c-fos expression, behavioural, endocrine and autonomic responses to acute social stress in male rats after chronic restraint: modulation by serotonin
2000
The effects in male rats of serotonin depletion (using the neurotoxin 5,7-dihydroxytryptamine) on the cross-sensitization of an acute social stress (defeat by a larger resident male) by previous repeated restraint stress (10 days, 60 min per day) was studied. Previous restraint increased freezing responses during social defeat in sham-operated rats, but this was not observed in those with depleted serotonin (83% or more in different regions of the brain). In contrast, neither heart rate (tachycardia) nor core temperature responses (hyperthermia) were accentuated in previously restrained rats (i.e. neither showed heterotypical sensitization), and neither adapted to repeated restraint (there …
Characterization of 5-hydroxytryptamine release from isolated rabbit and rat trachea: the role of neuroendocrine epithelial cells and mast cells
1995
Rabbit or rat isolated tracheae were incubated in vitro, and the release of 5-hydroxytryptamine (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) was determined by HPLC with electrochemical detection. Release of 5-HT from rabbit tracheae could be evoked by the calcium ionophore A 23187 and, in a calcium-dependent manner, by depolarizing concentrations of potassium (45 mmol/l), but not by the mast cell degranulating drug compound 48/80. High potassium- and A 23187-evoked release of 5-HT was markedly higher from tracheae of newborn compared to adult rabbits. In rabbit tracheae, mechanical removal of the mucosa resulted in 80-90% reduction in tissue 5-HT and in a similar reduction …
Electron microscopic study on the larval and adult corpus allatum of Oncopeltus fasciatus dallas (insecta, heteroptera)
1973
1. The ultrastructure of the corpora allata of last larval instars and adults of Oncopeltus was studied. The unpaired gland undergoes submicroscopic alterations and shows signs of degradation in old animals. The organ is partly covered and penetrated by corpus cardiacum tissue. Axons with different types of neurosecretory granules form synaptoid contacts with the corpus allatum cells.
Intraepidermal formation of Merkel cells in xenografts of human fetal skin.
1990
An experimental transplantation model using human fetal skin was applied to approach the question of the embryologic origin of human Merkel cells. Palmar and plantar skin from five fetuses, between 8 and 11 weeks of estimated gestational age (EGA), was xenografted to subcutaneous beds of nude mice. After 4 or 8 weeks of growth, biopsies were taken from these xenografts and examined for the presence of Merkel cells, using immunocytochemistry with antibodies specific for simple epithelial-type cytokeratins and neuron-specific enolase (NSE) as well as using electron microscopy. Skin from the same fetuses at the time of transplantation was screened in the same way. In all fetuses, no (or very s…
Merkel cells in ontogenesis of human nails
1993
Digital skin of human fetuses is known to contain a particularly high concentration of Merkel cells. Using antibodies against the simple epithelial cytokeratins (CK) 18 and 20, which are sensitive and specific Merkel cell markers, we studied immunohistochemically the main adnexal structure of digital skin, the nail anlage, in human fetuses (9-22 weeks of gestation) for the presence of Merkel cells. As early as week 9 some clustered Merkel cells were detected in the early matrix primordium. In specimens of week 12-15, abundant Merkel cells were found in the nail anlagen, particularly in the epithelium of the proximal nail-fold and the dorsal and ventral side of the apex region. In contrast, …
Persistent Tachypnea of Infancy. Usual and Aberrant.
2016
Persistent tachypnea of infancy (PTI) is a specific clinical entity of undefined etiology comprising the two diseases neuroendocrine cell hyperplasia of infancy (NEHI) and pulmonary interstitial glycogenosis. The outcome of typical NEHI is favorable. The outcome may be different for patients without a typical NEHI presentation, and thus a lung biopsy to differentiate the diseases is indicated.To determine whether infants with the characteristic clinical presentation and computed tomographic (CT) imaging of NEHI (referred to as "usual PTI") have long-term outcome and biopsy findings similar to those of infants with an aberrant presentation and/or with additional localized minor CT findings (…
Distribution and coexistence of chromogranin A-, serotonin-and pancreastatin-like immunoreactivity in endocrine-like cells of the human anal canal
1992
The comparative distribution and coexistence of chromogranin A (CGA)-, serotonin (5-hydroxytryptamine; 5-HT)- and pancreastatin (PST)-like immunoreactivity in endocrine-like cells of the human anal canal was investigated by light-microscopic immunocytochemistry. The largest population of colorectal endocrine-like cells consisted of CGA-immunoreactive (ir) cells, followed by the 5-HT-ir and PST-ir cell population. In the anal transitional zone (ATZ), CGA- and 5-HT-immunoreactivity was equally distributed; ir-PST was confined to a smaller endocrine-like cell population. In the squamous zone and the perianal skin, Merkel cells in the basal layer of the epidermis and hair follicles exhibited ir…
Coping with competition: neuroendocrine responses and cognitive variables.
2008
Confronting another individual or group motivated by the same goal is a very frequent situation in human communities that occurs in many other species. Competitive interactions emerge as critical situations that shed light on the effects and consequences of social stress on health. But more important than the situation itself is the way it is interpreted by the subject. This "appraisal" involves cognitive processes that contribute to explaining the neuroendocrine response to these interactions, helping to understanding the vulnerability or resistance to their effects. In this review, we defend the need to study human competition within the social stress framework, while maintaining an evolu…
Immunohistochemical localization of the pro-peptide processing enzymes PC1/PC3 and PC2 in the human anal canal.
1997
Abstract HORsch, D., R. Day, N. G. Seidah, E. Weihe and M. K.-H. SchAFer. Immunohistochemical localization of the pro-peptide processing enzymes PC1/PC3 and PC2 in the human anal canal. Peptides 18(5) 755–760, 1997.—The distribution of prohormone/pro-peptide convertases PC1/PC3 and PC2 was investigated in the human anal canal by immunohistochemistry. Both prohormone convertases exhibited region-specific distribution patterns and were observed in neural and neuroendocrine cells and in nonneuroendocrine cellular elements. PC1/PC3 immunoreactivity was present in enteric neurons, subsets of nerve fibers, and neuroendocrine cells, and also in epithelial cells like intestinal stem cells, and a su…
Electron microscopic immunogold cytochemistry reveals chromogranin A confined to secretory granules of porcine Merkel cells
1990
By ultrastructural immunohistochemistry using the immunogold technique, immunoreactive (ir) Chromogranin A (CGA) was found to be confined to the secretory vesicles of porcine Merkel cells. CGA was present predominantly in the periphery of the electron-dense core and on the clear halo. These findings indicate that CGA is a regular constituent of Merkel cell secretory granules but probably not exclusively responsible for their electron opacity.