Calbindins D-9kDa and -28kDa and enamel secretion in vitamin D-deficient and control rats

The present study focuses on the ultrastructure of enamel organ cells and the immunolocalization of calbindins D-9kDa and -28kDa during enamel secretion in Vitamin D-deficient rats. Vitamin D-deficiency disturbed the deposition of the layer of inner enamel and depleted the calbindins-content of ameloblasts. These data raise the possibility of a direct action of Vitamin D on the physiology of ameloblasts through ionic calcium homeostasis.     

Calbindin D-28k and parvalbumin in the rat nervous system

This paper describes the distribution of structures stained with mono- and polyclonal antibodies to the calcium-binding proteins calbindin D-28k and parvalbumin in the nervous system of adult rats. As a general characterization it can be stated that calbindin antibodies mainly label cells with thin, unmyelinated axons projecting in a diffuse manner. On the other hand, parvalbumin mostly occurs in cells with thick, myelinated axons and restricted, focused projection fields. The distinctive staining with antibodies against these two proteins can be observed throughout the nervous system. Calbindin D-28k is primarily associated with long-axon neurons (Golgi type I cells) exemplified by thalamic projection neurons, strionigral neurons, nucleus basalis Meynert neurons, cerebellar Purkinje cells, large spinal-, retinal-, cochlear- and vestibular ganglion cells. Calbindin D-28k occurs in all major pathways of the limbic system with the exception of the fornix. Calbindin D-28k is, however, also found in some short-axon cells (Golgi type II), represented by spinal cord interneurons in layer II and interneurons of the cerebral cortex. It is also detectable in some ependymal cells and abundantly occurs in vegetative centres of the hypothalamus. The "paracrine core" of the nervous system and its adjunct (1985, Nieuwenhuys, Chemoarchitecture of the Brain. Springer, Berlin) is very rich in calbindin D-28k. The distribution of calbindin D-28k-positive neurons is very similar to that of the dihydroperydine subtype of calcium channels. Most of the cells containing calbindin D-28k are vulnerable to neurodegenerative processes. Parvalbumin-immunoreactive neurons have a different, and mostly complementary distribution compared with those which react with calbindin D-28k antisera, but in a few cases (Purkinje cells of the cerebellum, spinal ganglion neurons), both calcium-binding proteins co-exist in the same neuron. Many parvalbumin-immunoreactive cells in the central nervous system are interneurons (Golgi type II) and, to a lesser extent, long-axon cells (Golgi type I), whereas conditions are vice versa in the peripheral nervous system. Intrinsic parvalbuminic neurons are prominent in the cerebral cortex, hippocampus, cerebellar cortex and spinal cord. Long-axon parvalbumin-immunoreactive neurons are, for example, the Purkinje cells, neurons of the thalamic reticular nucleus, globus pallidus, substantia nigra (pars reticulata) and a subpopulation among large spinal-, retinal-, cochlear- and vestibular ganglion cells. Parvalbumin is rich in cranial nerve nuclei related to eye movements. In addition to nervous elements, parvalbumin immunoreactivity occurs in a few ependymal cells and in some pillar cells of the organ of Corti.(ABSTRACT TRUNCATED AT 400 WORDS)     

Morphological Analysis of the Enamel Organ in Rats Treated with Fluoxetine

PURPOSE:

Previous studies have evaluated the presence of serotonin in the dental epithelia and mesenchyme during odontogenesis, suggesting its participation in tooth development.

MATERIALS AND METHODS:

Here, we used fluoxetine, a selective serotonin re-uptake inhibitor, at a dose of 10 mg/kg, administered for 20 days during pregnancy in 12 Wistar rats to examine the influence of this drug on the development of the enamel organ of the upper first molars of rat fetuses at 17 days of intra-uterine life (i.u.l.), and at one, five and ten days postpartum. The pregnant rats were anesthetized with xylazine at 10 mg/kg and ketamine at 25 mg/kg. The fetuses were removed and beheaded; their jaws were removed, and the upper jaws were exposed. The tissues were fixed in Bouin’s fixative, decalcified in 5% nitric acid for 4 – 12 h, conventionally processed for microscopy, and embedded in paraffin. Serial sections of approximately 5 μm were obtained and stained with hematoxylin and eosin, as well as periodic acid-Schiff.

RESULTS AND CONCLUSION:

Morphological analysis showed no structural changes in the experimental group compared to the controls, suggesting that, at the dose used, fluoxetine does not interfere with serotonin-mediated development of the enamel organ or the process of amelogenesis.     

Parvalbumin and calbindin D-28K immunoreactive neurons in area MT of rhesus monkey

The chemical characteristics of the neurons of the motion sensitive visual area, area MT, remain to be established. We studied the distribution pattern of two calcium binding proteins, parvalbumin (PV) and calbindin D28K (CB) in this area, using specific monoclonal antibodies and the peroxidase-antiperoxidase (PAP) immunohistochemical technique. Aldehyde fixed 30-micron-thick cryostat sections from area MT of five animals were processed free floating for immunohistochemical staining. Besides studying the morphological characteristics of PV and CB positive neurons, quantitative analysis was carried out to determine their (1) perikaryal area (Pa) and diameter, (2) numerical densities (NV)/mm3 cortical tissue, (3) absolute number (NC) in a column of cortex under 1 mm2 cortical surface along with (4) layerwise absolute number (NL) under 1 mm2 cortical surface and (5) laminar percentage distribution of immunoreactive (IR) neurons. Quantitative analysis was carried out using a Leica QMC 500 image analysis system connected to a DMRE microscope. The results showed that both types of IR neurons were localized to all cortical layers except layer I. The PV +ve neurons were equidistributed between the supra- and infragranular layers, with the highest percentage being present in layer III (45%) followed by layer V (21%). The CB +ve neurons, on the other hand, were predominantly localized in supragranular layers, with the highest percentage being in layer III (54%) and the next highest percentage in layer II (18%). The average Pa and diameter of PV +ve neurons were found to be 96.90 +/- 28.43 micron 2 and 11.01 +/- 1.61 microns respectively. The CB +ve neurons were significantly smaller in size than the PV +ve neurons, with average Pa and diameter of the former being 92.23 +/- 26.18 micron 2 and 10.39 +/- 1.23 microns respectively. The NV for PV and CB +ve neurons showed ranges of 3157-3894 and 2303-2585, with means of 3347 +/- 285 (+/- SD) and 3436 +/- 100 respectively. The values for NC showed ranges of 5230-5444 and 4020-4268 with means of 5378 +/- 85 and 4167 +/- 95 for PV and CB neurons respectively. Variations in size together with the differential distribution of these neurons in the cortical layers may indicate their involvement in different functional circuitaries.     

Postnatal development of parvalbumin and calbindin D-28k immunoreactivities in the canine hippocampus

The calcium-binding proteins, parvalbumin and calbindin D-28k, are markers of different classes of GABAergic interneurons and display different functions. The present study was attempted to determine immunoreactivities and colocalization of the parvalbumin and calbindin D-28k in the developing canine hippocampus by immunohistochemistry. The calcium-binding protein-containing neurons showed different developmental patterns. The first appearance of parvalbumin immunoreactive nonpyramidal cells was observed at P7. Parvalbumin immunoreactivity was elicited by the sequence from CA3 to CA1 to reach an adult-like distribution pattern, which was reached at P60, while calbindin D-28k immunoreactivity appeared from P0, including pyramidal and nonpyramidal cells. The characteristic distribution of calbindin D-28k immunoreactive pyramidal cells was clarified by P28, and an adult-like distribution pattern was reached by the end of the second postnatal month. Double-labeled nonpyramidal cells were frequently seen in the subareas, CA3 of P14/CA1-CA2 of P28, where parvalbumin immunoreactive nonpyramidal cells were emerging. These data suggest that the colocalization of the two calcium-binding proteins during development is related closely to the area-specific maturation of parvalbumin expression, although either prenatal expression of calbindin D-28k or parvalbumin was not determined.     

Comparison of calbindin D-28K immunoreactivity in superficial pineal bodies of mongolian gerbil and rat

Summary Immunocytochemical reaction for demonstration of calbindin D-28K has been performed in superficial pineal bodies of the Mongolian gerbil (Meriones unguiculatus) and the rat. Whereas in the Mongolian gerbil there were no clearly expressed calbindin immunoreactive cells, these were numerous in the rat pineal body. Here the calbindin-positive cells — probably pinealocytes — were disposed along capillaries. In view of the role of calbindin in binding and transporting calcium and regulating its intracellular levels, the absence of this protein in the gerbil pineal body has been interpreted as signifying the inability of pinealocytes to eliminate intracellular calcium with possible consequent formation of acervuli.Dedicated to Prof. Dr. Johannes Lang on the occasion of his 5th birthday     

Colocalization of parvalbumin, calretinin and calbindin D-28k in human cortical and subcortical visual structures

Several studies have demonstrated that three calcium-binding proteins parvalbumin (PV), calbindin D-28k (CB) and calretinin (CR) mark distinct subsets of cortical interneurons. This study demonstrates, in cortical and subcortical visual structures, the coexistence of two calcium-binding proteins in some neuronal subpopulations. The human visual cortex (VC), lateral geniculate nucleus (LGN), lateral inferior pulvinar (LIP) and superior colliculus (SC) were examined by a double-labelling immunocytochemical technique. The VC showed mostly separate populations of PV, CB and CR immunoreactive (-ir) interneurons, but also small populations of double-stained PV+CR and CR+CB neurons, while PV+CB neurons were less frequent. An average of 2.5% of the immunoreactive neurons were double-stained for PV+CR and 7.1% for CR+CB in area 17, while this percentage was slightly higher in association area 18 (3.3 and 7.4%, respectively). In the LGN and LIP, double-stained neurons were scarce, but in the fibre capsule of these nuclei, as well as in the optic radiation (OR) and white matter underlying area 17, both double-stained PV+CR or CR+CB and separate populations of PV-ir, CB-ir and CR-ir neurons and fibres were observed. Unlike the thalamic regions, the SC showed some double-stained PV+CR and CR+CB neurons, scattered both in the superficial and deep layers. These findings are discussed in the light of similar observations recently reported from other regions of the human brain.     

丹参对胃和十二指肠粘膜微循环血流和胃液分泌的影响

采用幽门结扎灌流法及氢气清除技术连续动态地观察了丹参注入前后,大鼠胃液分泌量、胃总酸度和胃及十二指肠粘膜血流量的改变,以深入探讨丹参的抗消化性溃疡,保护胃肠粘膜的作用机制。结果表明:丹参注入后40min左右,胃泌素刺激引起的胃液分泌亢进和胃酸排出增多均受到明显的抑制,效应持续120min以上;丹参注入20min左右,胃体和十二指肠粘膜的血流量分别增加了29.8%和43.7%(P<0.01)。在胃泌素引起最大胃液分泌亢进的同时,可伴有粘膜血流增多的趋势,但无统计学意义;上述结果提示,丹参能减少胃液的分泌和H~+的分泌,但其对胃肠粘膜的保护作用主要是借助改善粘膜的血液灌流而完成的。     

侧脑室注射神经降压素对大鼠胰腺外分泌的影响

借助于胰腺插管,对麻醉大鼠的胰液分泌进行观察。通过埋植于脑内的注射套管,观察微量注射神经降压素对胰腺外分泌的影响。实验结果发现,侧脑室注射1ng、10ng、12.5ng神经降压素,可使胰腺分泌量、碳酸氢盐和蛋白质排出量明显增加。侧脑室注射50ng、100ng神经降压素时,胰液分泌量、碳酸氢盐和蛋白质排出量则降低。静脉灌流阿托品,可完全阻断10ng神经降压素刺激胰液分泌和部分阻断50ng、100ng神经降压素抑制胰液分泌的作用。表明,神经降压素刺激胰腺外分泌的中枢作用可能经胆碱能神经机制介导。     

Isoflavone Genistein Induces Fluid Secretion and Morphological Changes in the Uteri of Post-Pubertal Rats

A reported increase in the incidence of infertility following high genistein intake could be related to alteration in the normal fluid volume and morphology of the uterus in adult female. In view of this, we investigated the effect of this compound on fluid secretion, fluid volume and morphology of the uterus in post-pubertal rats. Methods: Ovariectomised SD rats were treated with 17-β oestradiol (E) (0.8 X 10^-4 mg/kg/day) and genistein (0.5, 5, 10, 25, 50 and 100 mg/kg/day) for three days. Following drug treatment, in-vivo uterine perfusion was performed and the rate of fluid secretion and the volume of fluid in the uterus were determined via changes in weight (μl/min) and F-dextran concentration of the perfusate respectively. The animals were then sacrificed and the uteri were removed for weight determination, morphological analyses and proliferative cell nuclear antigen (PCNA) expression analyses by Western blotting. Results: Subcutaneous genistein treatment resulted in a dose-dependent increase in fluid secretion rate, fluid volume and uterine wet weight. Treatment with 100 mg/kg/day genistein resulted in a remarkable increase in the rate of uterine fluid secretion, the volume of the uterine luminal fluid as well as the circumference of the uterine and uterine glandular lumen suggesting an excessive fluid accumulation. Meanwhile, there were evidence of glandular hyperplasia and an increase in the expression of PCNA following treatment with 50 and 100 mg/kg/day genistein. Conclusion: High genistein intake could potentially cause adverse effects on the uterus by inducing excessive fluid secretion and accumulation as well as hyperplasia.     

Age-Related Peculiarities in Steroid Hormone Secretion and Behavior in Prenatally Stressed Female Rats in Novel Environment

We studied the effects of immobilization of female rat during days 15–18 of pregnancy on the behavior in novel environment (open field test) and blood level of steroid hormones in their female offspring depending on the cycle phase and age. The rats were tested at the age of 3, 12, and 24 months. Locomotor and exploratory activity and anxiety of control rats depended on the phase of estrous cycle. Age-related changes in the studied parameters were noted: locomotor and exploratory activity decreased and anxiety increased against the background of reduced secretion of the main ovarian hormones with age. In addition, blood estradiol level and behavior in novel environment virtually did not depend on age and estrous cycle phase in prenatally stressed females. Our fi ndings suggest that maternal stress has a modulatory effect on relationship between behavioral type and estrous cycle stage, as well as on age-related pattern of behavioral reactions.     

Abnormal neuronal expression of the calcium-binding proteins,parvalbumin and calbindin D-28k,in aged dogs

Disturbances of the gamma-aminobutyric acid (GABA) neurotransmitter system have been implicated in chronic degenerative neurological disease. Cognitive dysfunction and neuron loss are features in older dogs. GABAergic neurons also show immunoreactivity for specific calcium-binding proteins. Immunohistochemistry was used to study the neuronal expression of calbindin D-28k and parvalbumin in different areas of the brain in 13 dogs, aged between 2 and 13.5 years. Calbindin expression was found only in the cerebellum. There were significant differences in the quantity and distribution of neurons expressing these proteins between geriatric and adult brains. Parvalbumin- and calbindin-expressing neurons are relatively sensitive to degeneration in the cerebellum of older dogs. Parvalbumin labelling was associated with dystrophic structures that are commonly associated with ageing.     

Colocalization of parvalbumin and calbindin D-28k in neurons including chandelier cells of the human temporal neocortex

Chandelier cells are cortical GABAergic interneurons with a unique synaptic specificity enabling them to exert a strong inhibitory influence on pyramidal cells. By using immunocytochemistry for the calcium-binding protein calbindin D-28k in the human temporal neocortex, we have found numerous immunoreactive processes that were identified as chandelier cell axon terminals. This was a striking find since in previous immunocytochemical studies of the primate neocortex, chandelier cell axon terminals had been shown to be immunoreactive for another calcium-binding protein, parvalbumin, and colocalization studies indicate that parvalbumin and calbindin are present in almost completely separate neuronal populations. Here, we present double-label immunofluorescence experiments showing that parvalbumin and calbindin immunoreactivities are colocalized in certain neurons that include a subpopulation of chandelier cells whose cell bodies are located mainly in layers V and VI of the human temporal neocortex. The results suggest a selective laminar distribution of neurochemical subtypes of chandelier cells which is a peculiar feature of the organization of the human neocortex.     

低硒低维生素E粮对大鼠红细胞变形性的影响

以低硒（Ｓｅ）、低维生素Ｅ（ＶＥ）粮饲养大鼠，观察其血液流变学指标变化。结果表明，低Ｓｅ、低ＶＥ粮饲养大鼠的红细胞（ＲＢＣ）变形性、ＧＳＨ－ＰＸ和ＣｕＺｎＳＯＤ活力降低，ＲＢＣ压积、ＲＢＣ聚集性、ＲＢＣ聚集指数、脂质过氧化物增高。结果提示，Ｓｅ可能通过改变红细胞内表膜面Ｓｐｅｃｔｒｉｎ蛋白与ＲＢＣ膜骨架结合状态以及Ｓｅ和ＶＥ抗氧化损伤保护细胞膜结构完整性的作用，影响ＲＢＣ的变形性。     

可溶性趋化因子对人单核细胞表达及基质金属蛋白酶-9的影响

目的观察趋化因子Fractalkine（CX3CL1,Fkn）对人单核细胞株U937细胞表达与分泌基质金属蛋白酶-9（matrix metalloproteinase-9,MMP-9）的影响。方法使用不同浓度的人重组Fkn干预U937细胞,RT-PCR法检测细胞MMP-9基因表达,明胶酶谱法检测细胞上清中MMP-9水平。结果不同浓度人重组Fkn干预U937细胞MMP-9基因表达及上清中MMP-9水平低于空白对照组。结论Fkn可抑制U937细胞表达与分泌MMP-9。     

Distribution of the calcium-binding proteins parvalbumin, calbindin D-28k and calretinin in the retina of two teleosts

Using monoclonal antibodies against parvalbumin (PV) and calbindin (CB), and a polyclonal antiserum against calretinin (CR), the expression patterns of these proteins in the retina of the tench and rainbow trout were studied at light microscopic level in in toto preparations and radial sections. Parvalbumin was present in subpopulations of small amacrine cells in both species, but these cells were more abundant and had a clear centre-periphery gradient distribution in the tench. Using the McAB 300 monoclonal antibody against CB, glial cells such as Müller cells, astrocytes in the nerve fibre layer, and sparse large cells close to the entrance of the optic nerve were observed in both species. Moreover, this antibody strongly labelled H1 horizontal cells and their thick axon terminals in the tench retina, whereas only a small population of amacrine cells was stained in the trout. Calretinin was expressed in different types of ganglion cells and numerous neurones located in the inner plexiform layer in both species, but was more abundant and more strongly stained in the trout retina, where some bipolar cells were easily distinguishable. A comparison to current results in other vertebrate species is offered.     

Expression and changes of calbindin D-28k immunoreactivity in the ventral horn after transient spinal cord ischemia in rabbits

We examined ischemia-related changes of calbindin D-28k (CB) immunoreactivity in L(7) of the spinal ventral horn after transient spinal cord ischemia in rabbits. In the sham-operated group, CB immunoreactivity was not present in the spinal ventral horn, but CB immunoreactivity was detectable in the dorsal horn. CB immunoreactivity was detectable in the ventral horn at 30 min after ischemia: the CB immunoreactivity was found in glial cells identified as astrocytes. At 1 h after ischemia, CB immunoreactivity was highest and present at a few somata located in the lamina VII as well as many glial cells. CB immunoreactivity was lower in the lamina VII at 3 h after ischemia compared to 1 h post-ischemic group. By 2 days after ischemia, CB immunoreactivity was decreased in this region. In addition, the result of Western blot result showed the pattern of CB expression similar to that of immunohistochemistry. In conclusion, the ischemia-related changes of CB immunoreactivity in neurons and glial cells in the ischemic spinal ventral horn in rabbits may be related to modulation of intracellular calcium following transient ischemia.     

Allele frequencies of Mp6D-9 and GATT markers in 32 Turkish cystic fibrosis families

The allele frequency of GATT and Mp6D-9 markers was investigated in 32 cystic fibrosis (CF) families. The GATT₆ allele was found to be significantly associated with the ΔF508 mutation. The Mp6D-9 allele 2/GATT₆ haplotype was the major haplotype of the mutant alleles. Further analysis of CF alleles for population-specific mutations is underway so that a more direct approach can be taken, especially for families seeking prenatal diagnosis.