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Expression of epithelial membrane transporters in the developing mouse vomeronasl organ.
No full textThe developing mouse vomeronasal organ: immunohistochemical investigation of epithelial membrane transporters.
No full textTiming of neuronal intermediate filament proteins expression in the mouse vomeronasal organ during pre- and postnatal development. An immunohistochemical study
No full textSeveral types of intermediate filament proteins are expressed in developing and mature neurons; they cooperate with other
cytoskeletal components to sustain neuronal function from early neurogenesis onward. In this work the timing of expression
of nestin, peripherin, internexin, and the neuronal intermediate filament triplet [polypeptide subunits of low (NF-L), medium
(NF-M), and high (NF-H) molecular weight] was investigated in the developing fetal and postnatal mouse vomeronasal organ
(VNO) by means of immunohistochemistry. The results show that the sequence of expression of intermediate filament proteins
is internexin, nestin, and NF-M in the developing vomeronasal sensory epithelium; internexin, peripherin, and NF-M in the
developing vomeronasal nerve; and nestin, internexin and peripherin, NF-L, and NF-M in the nerve supply to accessory structures
of the VNO. At sexual maturity (2 months) NF-M is only expressed in vomeronasal neurons and NF-M, NF-L and peripherin are
expressed in extrinsic nerves supplying VNO structures. The differential distribution of intermediate filament proteins in the
vomeronasal sensory epithelium and nerve is discussed in terms of the cell types present therein. It is concluded that several
intermediate filament proteins are sequentially expressed during intrauterine development of the VNO neural structures in a
different pattern according to the different components of the VNO
Neuronal nitric oxide synthase expression in the mouse vomeronasal organ during prenatal development
No full textThe presence and distribution of immunoreactivity for nitric oxide synthase type I and a panel of regulatory neuropeptides was investigated in the vomeronasal organ (VNO) of mouse embryos. Results show that nitric oxide synthase type I is first expressed in putative extrinsic nerve fibers reaching areas of vascular development at embryonic day 16 and in the vomeronasal nerve at embryonic day 15. Immunoreactivity for vasoactive intestinal peptide appears around developing vessels of the VNO during embryonic day 18. No immunoreactivity for atrial natriuretic peptide, substance P and calcitonin gene-related peptide is present in the VNO. It is concluded that, in the mouse, nitric oxide synthesis is a precocious event in the development of peripheral and central neural vomeronasal structures, representing a very early step in the neurochemical maturation of the VNO
Immunohistochemical evidence suggests intrinsic regulatory activity of human eccrine sweat glands
No full textImmunohistochemistry of normal eccrine sweat glands was performed on paraffin sections of human skin. Immunoreactivity (ir) for neuron specific enolase, S100 protein (S100), regulatory peptides, nitric oxide synthase type I (NOS-I) and choline-acetyltransferase (ChAT) was found in small nerve bundles close to sweat glands. In the glands, secretory cells were labelled with anticytokeratin antibody. Using antibodies to S100, calcitonin gene-related peptide (CGRP) and substance P (SP) a specific distribution pattern was found in secretory cells. Granulated (dark) and parietal (clear) cells were immunopositive for CGRP, and S100 and SP, respectively. Immunoreactivity was diffuse in the cytoplasm for CGRP and S100, and peripheral for SP. Myoepithelial cells were not labelled. Electron microscopy revealed electron dense granules, probably containing peptide, in granulated cells. Using antibodies to NOS-I and ChAT, ir was exclusively found in myoepithelial cells. Immunoreactivity for the atrial natriuretic peptide was absent in sweat glands. These results provide evidence for the presence of both regulatory peptides involved in vasodilation and key enzymes for the synthesis of nitric oxide and acetylcholine in the secretory coil of human sweat glands. It is suggested that human sweat glands are capable of some intrinsic regulation in addition to that carried out by their nerve supply
Fat body of the frog Rana esculenta: An ultrastructural study
No full textIn the frog, the fat body is the largest body lipid deposit and is associated with the gonad. The aim of the present work was to investigate the fine structure of the fat body at different periods of the annual cycle and during prolonged starvation. Results indicate that fat body cells of Rana esculenta caught in autumn and after winter hibernation resemble mammalian adipocytes of white adipose tissue and contain markers of adipose tissue, such as S-100 protein and lipoproteinlipase. However, unlike mammalian adipocytes, fat body adipocytes consistently show small lipid droplets associated with their single, large lipid deposits, a lack of a definite external lamina, and the presence of cellular prolongations and spicula at their surfaces. Transmission and scanning electron microscopy in association with lanthanum tracer experiments suggest that in fat body adipocytes a vesicular-tubular system connects the cytoplasm and the interstitial space. In June (i.e., during the reproductive period), fat body adipocytes appear to have lost much of their lipid deposit and adjacent adipocytes show interdigitation of their plasma membranes and prominent Golgi complexes. In starved frogs, fat body cells can be almost devoid of lipid and in regression to a near-mesenchymal state. Nevertheless, these fat bodies still contain lipoproteinlipase activity ( apprx 45% of that found in lipid-filled ones), indicating persistent adipose differentiation of the cells therein. Results presented here show that the R. esculenta fat body is an adipose organ undergoing reversible extreme changes in adipocyte fat content, which are associated with definite ultrastructural features. The fat body represents a suitable model for studying adipose tissue under different and extreme physiological conditions
Adipocyte morphology during hormone-induced lipid deposition and mobilization: an ultrastructural investigation in the perfused cardiac fat.
No full textThe rat pericoronary adipose tissue was perfused in the presence of either the liposynthetic hormone insulin or the lipolytic hormone noradrenaline. Insulin perfusion associated with a) larger adipocyte mean sectional diameter in comparison with noradrenaline perfusion; b) glycogen deposition; c) appearance of small fat globules at discrete sites at the periphery of the main lipid drop. The two latter phenomena were apparently dose-dependent. Massive lipid deposition was induced by addition of triglycerides to the perfusion medium and this associated with appearance of prominent endoplasmic reticulum in the cytoplasm. In noradrenaline-perfused adipose tissue many small lipid droplets surrounded the central lipid deposit and the endoplasmic reticulum was in the form of both thin long, dashed cisternae sometime surrounding lipid droplets and grouped, anastomosing tubular cisternae. The present work shows that the perfused white adipose tissue of the heart is a suitable model to study, in situ, the morphological effects of hormones in adipocytes. © 1995 Academic Press. All rights reserved
MRI investigation of liver and myocardium iron overload induced by iron-rich feeding in rats.
No full textThe aim of this study was to establish
weather intensive iron introduction by feeding can lead to cardiac iron
overload in addition to the well-established hepatic iron overload in rats. Iron
assessment in both myocardium and liver was performed non-invasively by
MRI, according to previously published methods.
Our results show that intensive iron introduction
by feeding does not implicate significant heart iron accumulation
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