bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catecholamine synapses and contents in the paraventricular hypothalamic nucleus and nucleus tractus solitarius of DOCA‐salt hypertensive rats
Authors: Hwang Bang H. , Chiueh Chuang C. , Severs Walter B. 
Published: February 2005

AbstractCentral catecholamine (CA) neurons in the nucleus tractus solitarius (NTS) and paraventricular hypothalamic nucleus (PVN) were studied in Wistar rats that had been unilaterally nephrectomized. The experimental animals were then treated with deoxycorticosterone acetate (DOCA) and salt water. The control animals were treated with the vehicle and tap water. Blood pressure of animals 4 weeks after DOCA/salt treatment was significantly elevated when compared to control rats. Morphologically, CA terminals showed no noticeable changes in the DOCA/salt hypertensive rats. Furthermore, the density of CA terminals either in the NTS or in the PVN of the DOCA/salt hypertensive rats was not statistically different from that of normotensive controls, suggesting that salt does not cause lesions or destruction of CA terminals. However, an extensive electron‐microscopic morphometric analysis indicated that there was an enhancement of CA synaptogenesis (expressed by increased synaptic frequency among all CA boutons labeled with 5‐hydroxydopamine) in the PVN, but not in the NTS of DOCA/salt hypertensive rats. In addition, the high‐performance liquid chromatography revealed decreased CA contents in the PVN, but not in the NTS, of DOCA/salt hypertensive animals. Since synapses are primary sites for neurotransmitter release, the above results collectively suggest that more CA synapses formed in the PVN may reflect a net CA release from CA terminals resulting in the decreased CA content in the axonal terminals. Such an increased CA release and enhanced CA synaptogenesis may consequently enhance CA function in the PVN of hypertensive rats 4 weeks after DOCA/salt treatment, and relate to the development and/or maintenance of hypertension in the DOCA/salt rats.
Distribution of plasmelemmal vesicles on arterial endothelial surface as determined by freeze cleavage
Authors: Jan Kung‐Ming 
Published: February 2005

AbstractThe freeze‐fracture technique was used to study the density and distribution of plasmalemmal vesicles at the endothelial surface of canine carotid arteries. The fractured surface of the endothelium can be divided into areas with vesicles (Aves) and areas without vesicles (Anves), the latter being located at the parajunctional zone. With morphometric analysis, Aves and Anves were found to be 75% and 25% of the endothelial surface, respectively. The average width of Anves (distance from the intercellular cleft) is approxmately 0.4 μ. In Aves, the density of vesicles is 120 μm−2, and approxmately 16% of Aves is covered by the vesicle orifices. The tight junctions appear as long and straight strands, 8–9 nm in width. The number of the strands varies from one to five. The gap junctions consist of closely packed particles 9–10 nm in size which form patches or plaques from 80 to 800 nm in size. These findings provide the quantitative information needed for the theoretical modeling of transendeothelial vesicular transport of macromolecules.
Morphology of the erect glans penis in rats under various gonadal hormone conditions
Authors: Sachs Benjamin D. , Glater Glen B. , O'Hanlon Joyce K. 
Published: February 2005

AbstractThe scanning electron microscope (SEM) was used to compare erect and nonerect penile glandes of gonadally intact Norway rats (group I) and of castrated rats exposed to the following hormonal conditions: maintained with testosterone (T)‐filled Silastic capsules implanted subcutaneously (group T); maintained with implants of estradiol (E) for 8 or 12 days (group E1); maintained with E implants for 10 weeks (group E10); maintained with E implants for 9 weeks, then injected daily with testosterone propionate for 8 or 17 days (group E/T). As in previous SEM depictions of nonerect glandes of intact rats, spines projected toward the base of the glans at a shallow angle from the sulci of deep epithelial folds. In contrast, the folds on erect glandes of groups I and T were completely smoothed, and the spines were themselves erected. The penile cup formed at the distal end of the erect glans also contained spines; these were centrifugally directed at the rim and centripetally directed on the inner surface of the cup. The glandes of group E1 males were similar to those in groups I and T, with the spines showing no disorientation. Males in group E10 lacked spines in the cup and along most of the shaft of the glans, but erection revealed many sharp spines just proximal to the cup and on its rim. In group E/T, no papillae were detectable on the nonerect glandes, but erection revealed many small rounded papillae on the shaft and within the cup. The erection of the spines that occurs on the shaft and in the cup of the erect glans may facilitate previously proposed functions on the spines, including vaginal and cervical stimulation and removal of the copulatory plug. Our perfusion method may also facilitate estimation of the number, size, distribution, and hormonal sensitivity of penile papillae.
Endocrine cell populations in the colon and rectum of cat, dog, and monkey: Fine structure, immunocytochemistry, and distribution
Authors: Peranzi Gabriel , Lehy Thérèse 
Published: February 2005

AbstractComparative and quantitative ultrastructural studies of endocrine cells from the large bowel of European cat, beagle dog, and the monkey Callitrix jacchus were performed. The cat and monkey exhibited a roughly similar distribution of colonic endocrine cells with a frequency increasing toward the distal colon. On the contrary, the highest endocrine cell frequency in the dog colon was found in the cecum. In the dog and monkey, enterochromaffin (EC) cells were predominant in all segments. In the cat, non‐EC cells were predominant in the proximal colon. For each colonic segment, relative percentages of EC and non‐EC cells appeared on the whole to be roughly stable between individuals of the same species. Three subtypes of EC cells were distinguished in each species. Non‐EC cells were characterized by large variation in size and electron densities of their granules: Mean granule size per cell extended from 210 to 850 nm in cat, 310 to 770 nm in dog, and 130 to 470 nm in monkey. In each species, statistical analyses indicated that the non‐EC cell population was composed of two or more subpopulations. Some similarities were found between colonic endocrine cells of the monkey and man, whereas obvious differences appeared between the two carnivorous mammals. Immunocytochemical studies demonstrated the presence of cells containing enteroglucagon, somatostatin, or a pancreatic polypeptidelike substance in the colon of the monkey and the rectum of the three mammals. Correlative immunocytochemical and ultrastructural studies showed that the three kinds of immunostained endocrine non‐EC cells in each species had rather round granules, with great electron densities. Some subpopulations, morphologically distinguished, did not react to any of the antisera used. This suggests either the existence of secretory cycle in some endocrine cells or, perhaps, the presence of peptides still unknown in this part of the gut.
Chronic infusion of opiate peptides to rat cerebrospinal fluid with osmotic minipumps
Authors: Saland L. C. , Ortiz E. , Samora A. 
Published: February 2005

AbstractBeta‐endorphin‐related opiate peptides or the opiate antagonist naloxone were chronically infused for periods of 24 to 48 hours to the lateral cerebral ventricle of adult male rats using Alza osmotic minipumps. Previous studies have suggested a “chemotactic”‐like effect of opiate peptides for supraependymal macrophages in the region of the third ventricle of the brain. The present study demonstrates a stimulatory effect of beta‐endorphin infusion on the appearance of lymphocyte and neutrophil‐like cells, in addition to macrophages, in the region of the third ventricle, suggestive of an intracerebral inflammatory response. None of the other molecules, including alphaendorphin, methionine‐enkephalin, naloxone, or sterile saline produced similar cellular responses after infusion, although some of the latter substances may have induced the appearance of supraependymal neuron‐like cells in the area. Observations suggest that the chronic presence of beta‐endorphin, a biologically active opiate peptide, will interact with cells of the immune system, which have the ability to gain access to the cerebrospinal fluid.
Structural development of the feline mental nerve
Authors: Fried K. 
Published: February 2005

AbstractThe qualitative and quantitative structural development of the feline mental nerve (MN), a branch of the inferior alveolar nerve (IAN), was studied by electron microscopy from 40 days postconception (dpc) (about 2 weeks before birth) to 11 years after birth. Myelination was initiated at 40–45 dpc. At 2 months after birth de novo myelination was completed, and the larger myelinated axons had achieved a fully differentiated nodal‐paranodal morphology. Size growth of myelinated axons continued until 6 months, when a bimodal size distribution between 1 and 12 months was established. When compared to the IAN, the MN contained a higher proportion of unmyelinated axons. Age‐related signs of axon degeneration, which previously were recorded in the IAN, were lacking in the MN. This suggests that senescent IAN axon degeneration is related to dental rather than to cutaneous MN branches.
An autoradiographic study of the mouse olfactory epithelium: Evidence for long‐lived receptors
Authors: Hinds James W. , Hinds Patricia L. , McNelly Nancy A. 
Published: February 2005

AbstractIn order to try to determine whether differentiated olfactory receptors turn over (die and are replaced by newly differentiated cells) during adult life, mice were injected with a single dose of 3H‐thymidine at either 2 or 4 months of age and allowed to survive for up to 12 months; they were caged in a laminar flow unit to prevent rhinitis. Counts of labeled receptor cells detected autoradiographically after injection at 2 months of age revealed that, following an initial decrease from 1 to 3 months of survival, numbers of labeled cells remained approximately constant, at least up to 12 months of survival. Cells still labeled at 12 months of survival were confirmed as receptor cells by electron microscopic examination of reembedded sections. The hypothesis is suggested that in the absence of disease‐related destruction of the olfactory epithelium, most or all receptor cell turnover represents newly formed cells that fail to establish synapses with the olfactory bulb; fully differentiated receptor cells may be quite long‐lived.
Ultrastructural localization of glycosaminoglycans in human term placenta
Authors: Parmley R. T. , Takagi M. , Denys F. R. 
Published: February 2005

AbstractSulfated glycoconjugates were stained in normal human term placentas using Spicer's high‐iron diamine (HID) method with thiocarbohydrazide and silver proteinate (TCH‐SP) enhancement. Specific identification of glycosaminoglycans (GAG) was accomplished by digestion of the stained material with chondroitinase ABC or AC for removal of chondroitin sulfates and nitrous acid for removal of N‐sulfated GAGs. The syncytiotrophoblast apical surface demonstrated moderate to intense staining with HID‐TCH‐SP, which was removed by prior digestion with the chondroitinases, but not by nitrous acid. The syncytiotrophoblast basal surface and endothelial cell surfaces lacked sulfate staining. A few cytoplasmic granules in syncytiotrophoblast cells demonstrated staining similar to the apical surface. Three layers of the basal lamina were identified in these preparations. The lamina lucida immediately beneath the syncytiotrophoblast and the majority of the lamina densa stained weakly or not at all, whereas the underlying lamina diffusa and stroma demonstrated moderate to intense staining. The majority of lamina diffusa staining was removed by chondroitinase ABC or AC; the remaining material was removed by nitrous acid digestion. Thus the syncytiotrophoblast surface contains a chondroitin sulfate and the basal lamina contains a mixture of intensely stained chondroitin sulfate and a weakly stained N‐sulfated GAG.
The value of graphic reconstructions—comparison with scanning electron microscopy
Authors: Wenink Arnold C. G. , Chon Yong 
Published: February 2005

AbstractBecause knowledge of spatial morphology of the human embryonic heart mainly derives from serial microscopic sections and from reconstructions based on such series, it might be questioned whether the results obtained are comparable with animal studies in which scanning electron microscopy is used. Therefore, pig embryo hearts of the same developmental stage were processed for routine histological sectioning as well as for scanning electron microscopy. A graphic reconstruction was made of a right ventricular view, to be compared with a similar scanning micrograph. The two images, produced by much different techniques, were strikingly similar. In addition, the graphic reconstruction technique is complementary to scanning electron microscopy, because histological details can be introduced.
Redistribution of gastric K+‐NPPase in vertebrate oxyntic cells in relation to hydrochloric acid secretion: A cytochemical study
Authors: Koenig Cecilia S. 
Published: February 2005

AbstractGastric K+‐NPPase represents a partial reaction of the (K+‐H+)ATPase system, which is considered to be the proton pump in mammalian parietal cells. In the present paper, K+‐NPPase activity was cytochemically studied by the method of Mayahara et al. (1980) in gastric glands of birds, amphibia, and mammals, either in the resting state induced by cimetidine or after stimulation of HC1 secretion by histamine.The gastric K+‐NPPase cytochemical reaction was localized only in oxyntic cells of the gastric mucosa in the three species tested.The subcellular distribution of the K+‐NPPase reaction product drastically changes with the secretory state of HC1. In resting cells, the K+‐NPPase staining is associated with the membranes of the endocellular tubular system while in HC1‐secreting cells, it is associated with the plasma membrane of the elaborate secretory surface characteristic of this functional state. The above results demonstrate that the same enzymatic activity, which is associated with the gastric proton pump, is present in both membranous systems of the oxyntic cell secretory pole. This fact supports the proposal that the tubular system represents a membrane reserve that inserts the proton pump into the luminal plasma membrane in vertebrate oxyntic cells under the action of HC1 secretagogues.
The development of the osmiophilic inclusion bodies within the granular pneumocyte of chicken lung
Authors: López J. , Sesma P. , Vázquez J. J. 
Published: February 2005

AbstractThe origin and development of osmiophilic inclusion bodies (OIB) type A of granular pneumocytes were morphologically studied in chicken lungs. The OIB type A were formed by a process of twisting and progressive spiralling of profiles of the rough endoplasmic reticulum (RER). No evidence has been found in favor of a mitochondrial or Golgi‐related origin of OIB.
Ultrastructural characterization of glial cells in the rat pineal gland with special reference to the pineal stalk
Authors: Luo Z. R. , Schultz R. L. , Whitter E. F. , Vollrath L. 
Published: February 2005

AbstractIn the present study the “interstitial” cells of the superficial pineal gland and the nonparenchymal cells of the pineal stalk in Sprague‐Dawley rats were examined ultrastructurally with the aim of defining the cells more closely. The “interstitial” cells of the superficial pineal gland do not represent a homogeneous cell population. The most abundant cell type is the mononuclear phagocyte, most easily recognized by its dark appearance and its content of primary and conspicuous secondary lysosomes. Astrocytes can be distinguished by the typical appearance of their nuclei (i.e., a thin continuous rim of heterochromatin adjacent to the nuclear membrane), identical to that of astrocytes in the CNS. Depending on the absence or presence of glial filaments and their amount, a spectrum of astrocytic cells is present. Mature astrocytes with filaments throughout their cytoplasm are rare. Immature glial cells with few or no filaments predominate. In the vicinity of blood vessels pericytes are present. In view of the fact that the “interstitial” cells could generally be identified it is suggested to abandon the term interstitial for the cells in question. In the pineal stalk mature astrocytes predominate; they have some features in common with pinealocytes, i.e., the presence of intergrade endoplasmic reticulum and grumose bodies (lysosomes). Other unusual features are a relative abundance of coated pits and vesicles. Oligodendrocytes are restricted to the proximal part of the stalk, near the deep pineal, where myelinated axons are abundant. More distally a few Schwann cells were seen.
Alterations of lmmunoreactive somatostatin in thyroid C cells after induced hypercalcemia, hypocalcemia, and antithyroid drug treatment
Authors: Kameda Yoko , Ito Miyoshi , Ogawa Koichi , Tagawa Takasuke 
Published: February 2005

AbstractIn order to elucidate the functional significance of somatostatin in thyroid C cells, the alterations of immunoreactive somatostatin in the cells were investigated under various experimental conditions, i.e., hypercalcemia, hypocalcemia, and antithyroid drug treatment. Guinea pigs and rabbits, in which almost all C cells reveal the intense immunoreaction for somatostatin in addition to calcitonin, were used as experimental animals. After chronically induced hypercalcemia, somatostatin immunoreactivity conspicuously diminished coinciding with the decrease of calcitonin; somatostatin as well as calcitonin was responsive to induced hypercalcemia. After hypocalcemic tetany induced by injection of Escherichia coli Lasparaginase, C cells exhibited very intense immunoreactions for both calcitonin and somatostatin. After chronic treatment of ethylenethiourea, immunoreaction of somatostatin in C cells was the same as that of calcitonin. That is, when immunoreactivity for calcitonin remained unchanged, immunoreactivity for somatostatin was also intensive. However, when immunoreaction of calcitonin became very weak, the reaction of somatostatin was also weak. Thus, in all experimental conditions examined the alterations of immunoreactive somatostatin in C cells completely coincided with those of calcitonin. It seems likely that somatostatin in thyroid C cells exerts the synergistic effect on calcitonin action.
Autoradiographic localization of 3H‐digoxin binding by neural cells in the medulla
Authors: Traurig H. H. , Bhagat A. , Bass N. H. 
Published: February 2005

AbstractThe purpose of this investigation was to localize binding sites for the cardiac glycoside digoxin in the medulla of the rat in vivo. Adult male Sprague‐Dawley rats were injected (IV) with 3H‐digoxin and killed 30 minutes later. Autoradiographs of medullas showed evidence of 3H‐digoxin binding to small‐ and medium‐sized neural cells in the regions of the nucleus solitarius, dorsal motor nucleus of the vagus, area postrema, and in the zone between the area postrema and the underlying neuropil. However, the parasympathetic preganglionic neurons of the dorsal motor nucleus were not labeled. The 3H‐digoxin‐labeled cells in the medulla were located mainly in the commissural and medial portions of nucleus solitarius at the level of the area postrema. Animals injected with unlabeled digoxin followed by 3H‐digoxin showed reduced binding of radioactivity.The small‐ and medium‐sized neurons of the caudal portions of the nucleus solitarius are internuncial in position with respect to cardiovascular afferents of the glossopharyngeal and vagus nerves and sympathetic and parasympathetic cardiovascular efferent neurons of the medulla. The results of this study suggest that these 3H‐digoxin‐labeled cells, presumably neurons of nucleus solitarius, may possess high affinity binding sites for digoxin. Further, the area postrema, which lacks a blood‐brain barrier, may provide a portal of entry for 3H‐digoxin into regions of the medulla known to contain neurons that play a role in the regulation of cardiac rhythm.
Transport of horseradish peroxidase across monkey trophoblastic epithelium in coated and uncoated vesicles
Authors: Wilson Jean M. , King Barry F. 
Published: February 2005

AbstractThis study used membranous chorion of the macaque monkey placenta to examine uptake and processing of exogenous proteins. Tissue was incubated with either cationic or anionic horseradish peroxidase. Incubation time was varied between 5–25 min to follow the endocytic pathways. In spite of some differences in binding, uptake and processing of the isozymes was similar. In the presence of tracers at 37°C both horseradish peroxidases were taken up in large (150–175) nm diameter coated vesicles. In addition, coated tubules 300–400 nm in length and 50–100 nm in diameter were seen in the apical cytoplasm. Often, the tubules bud off small (85–105 nm diameter) protein‐filled coated vesicles which traversed the cytoplasm and fused with the basal‐lateral plasma membrane. In other cases, the tubules or vesicles lost their clathrin coats and fused to form larger endocytic vesicles which later fused with phagolysosomes. After longer incubation, larger uncoated vesicles (endosomes) were seen releasing their contents at the basal‐lateral membrane. These results suggest that multiple transport pathways exist in this epithelium. The first, involving only coated structures, may function to sort and concentrate specific ligands important for embryonic development. The second, involving the formation and translocation of large uncoated vesicles to the basal‐lateral membrane, may also provide nutrients to the embryo. A third pathway directs the protein to phagolysosomes where it is presumably degraded. Degradation products could be used by the cells of the membranous chorion or may provide nutrients to the embryo.
The relation of nucleolus diameter to cell body diameter in mammalian dorsal root ganglion cells
Authors: Coggeshall Richard E. , Chung Kyungsoon , Bee David E. 
Published: February 2005

AbstractThe present study correlates cell body and nucleolar sizes for dorsal root ganglion cells in the rat. To do this, we measured cell body areas and calculated their diameters and measured nucleolar diameters for 719 cells. These data indicate that there is a correlation in that increasing cell size is associated with increasing nucleolar size. However, there is considerable variability of cell body size for each nucleolar diameter and vice versa. Nevertheless, when nucleolar diameters are grouped, the function In D = 1.687 + 0.334 dr, where D is the diameter of the cell body and dr the rounded diameter of the nucleolus, produced an almost straight line. Thus this formula provides a good estimate of the relation of nucleolar and cell body sizes for dorsal root ganglion cells of the rat. In addition, estimates of the variances of cell body size at each nucleolar diameter are provided.