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PubMed1997

Characterization of alpha, beta-methylene ATP binding sites in mouse crude synaptic membranes.

Since ATP has been reported to be a potent excitatory transmitter in the mammalian central nervous system (CNS), we studied the neurochemical characters of the binding sites of alpha,beta-methylene ATP, an agonist of P2x receptors, in mouse crude synaptic membranes. ATP and its related compounds inhibited [3H] alpha,beta-methylene ATP binding in a concentration-dependent manner. The potency order in the inhibition of the binding was as follows; alpha,beta-methylene ATP = ADP beta S > ATP gamma S > ATP > or = ADP > beta,gamma-methylene ATP >> UTP > 2-methylthio ATP. And adenosine did not affect the binding. The order was different from those reported in peripheral tissues. And Sr2+, Ca2+, Mg2+, and Cd2+ enhanced the binding. These results suggest that alpha,beta-methylene ATP binding sites in CNS have different characters from those in peripheral tissues.

Adenosine Triphosphate↗
PubMed1979

The differential effect of insulin in vivo on the peripheral utilization of glucose and ketone bodies in the rat.

This in vivo study assessed the immediate effects of insulin on glucose and ketone body utilization in the fed, fasted, and diabetic ketoacidotic rat. The experimental design consisted of the functional removal of the liver (the site of glucose and ketone body production) and the pancreas from the anesthetized animals. This surgical procedure permitted the assessment of the effect of exogenously administered insulin on the rate of both glucose and ketone body utilization by peripheral tissues. Insulin exerted hypoglycemic activity in all three metabolic states studied. This hypoglycemic activity contrasted to the lack of demonstrable effect of this hormone on ketone body uptake by peripheral tissues. It was concluded that in the rat, the immediate effect of insulin, i.e. within 30 minutes, was to exert hypoglycemic activity without simultaneous hypoketoniemic activity.

Animals↗
PubMed1985

The binding of [3H]mepyramine to histamine H1 receptors in monkey brain.

Several laboratories have reported ligand binding studies using radioactive histamine H1 antagonists to label the H1 receptors in mammalian brain. We have extended these studies to a detailed examination of the binding of [3H]mepyramine to monkey brain and have shown that the distribution is similar to that in man, with specific binding sites being concentrated in the frontal cortex with relatively low binding to the pons and basal ganglia. The binding shows a single saturable component with a KD of about 1 nM and a Hill plot slope close to unity. These observations are the same for all structures tested. Comparison with data from other laboratories suggests that in this species, the histamine receptor is the same as that in peripheral tissues. From Ki values for various ligands and comparison of KD estimates in other species, the receptor seems to be essentially identical to the H1 receptor in central and peripheral tissues of the guinea pig and also to that in human brain. The rat and possibly the dog have minor differences from the monkey in terms of KD values for [3H]mepyramine binding.

Aminopyridines↗
PubMed2002

The "other" circadian system: food as a Zeitgeber.

It is not surprising that limiting food access to a particular time of day has profound effects on the behavior and physiology of animals. It has been clear for some time that pre-meal behavioral activation, a rise in core temperature, elevated serum corticosterone, and an increase in duodenal disaccharidases are under circadian control and that the observed circadian properties are not abolished by lesions of the suprachiasmatic nucleus (SCN), but the search for the locus of a separate food-entrainable oscillator (FEO) has not been successful. The cloning of circadian clock genes and the discovery that these genes are expressed in many central nervous system structures outside the SCN and in peripheral tissues have led to new strategies for investigating potential loci of an FEO. Recent findings concerning the entrainment of clock gene expression in the central nervous system and in peripheral tissues by periodic food access are presented, and the implications of these findings for a better understanding of a circadian system that entrains to meals, rather than to light, are discussed.

Animals↗
PubMedDate not supplied

MT1 melatonin receptor mRNA tissular localization by PCR amplification.

OBJECTIVES: The pineal gland transduces photoperiodic informations to the neuroendocrine axis through the nocturnally melatonin secretion. This hormonal message plays a major role in the biological rhythm regulation. By autoradiography, more than 130 melatonin putative targets have been reported in the central nervous system (CNS) and in peripheral tissues. However, cross-species consensus concern only a few of them like the suprachiasmatic nuclei (SCN), the master circadian clock, and the pars tuberalis of the pituitary. Recently, MT1 melatonin receptor cDNA have been cloned in several mammals providing us with new tools to investigate its tissular location at the gene level. In the present study, we report a screening for MT1 mRNA by RT-PCR amplification of numerous tissue mRNA. METHOD: mRNA were extracted from a large variety of rat tissues. To semi-quantify the melatonin receptor mRNA expression level, each cDNA was amplified concomitantly with both beta-actin and MT1 specific primers. RESULTS: In central and peripheral tissues previously reported to bind melatonin, strong PCR signals were logically observed. More surprisingly, a vast majority of studied tissues express MT1 mRNA and then might be responsive to melatonin. CONCLUSION: Numerous biological functions express diurnal rhythmicity and internal-synchronization. As, most of them apparently do not receive any out-coming neuronal message from the SCN, endocrine communication was proposed to support biological rhythm synchronization. Our present data strengthen the idea that the nocturnally restricted melatonin secretion could be one internal zeitgeber that putatively distributes the endogenous circadian rhythmicity to all tissues expressing melatonin receptors.

Actins↗
PubMed1985

Phenotypic expression of T lymphocytes in thymus and peripheral lymphoid tissues.

The pattern of expression of cell surface antigens and their relationship to the sequence of T-cell differentiation were delineated by the application of a series of monoclonal antibodies against T cells on tissue sections. The morphologic features and location of T-cell differentiation can be categorized into four stages: 1) subcapsular thymocytes, 2) cortical thymocytes, 3) medullary thymocytes, and 4) peripheral T cells. Phenotypically, on the basis of reactivity with monoclonal antibodies, T cells could be separated into two groups: immature and mature T cells. All stages of T cells expressed T200, Lyt 3, Leu 1, OKT3, Leu 9, and TA1, although staining intensities varied between thymic cortex and medulla. Mature T cells (medullary thymocytes and peripheral T cells) stained more intensely than immature T cells for some antigens, such as Leu 1, OKT3, and Leu 9, and, therefore, probably have a greater antigen density. Immature T cells, exemplified by subcapsular and cortical thymocytes, were characterized by the expression of Tdt, Leu M3, OKT6, OKT9, J5, BA-2, OKT10, and usually coexpressed both helper (T4/Leu 3a) and suppressor (T8/Leu 2a) antigens. With further maturation, medullary thymocytes and peripheral T cells lost reactivity for the above-mentioned markers, acquired A1G3 and Leu 8, and segregated into either T4+/Leu 3a+ or T8+/Leu 2a+ cells. A subpopulation of T cells in germinal centers differs from the majority of peripheral T cells by virtue of an absence of expression of Leu 8/A1G3. This histologically localized subset of T cells may be responsible for the mediation of helper function within the germinal center.

Animals↗
PubMedDate not supplied

[Photoelectric intraoperative diagnosis of brain tumors].

Intraoperative examination of 43 neuro-oncological patients was conducted. The exact boundaries of the tumors and their extension into tumorous cysts and the ventricles of the brain were determined by means of a puncture cannula fitted with a photoelectric transducer. Comparative analysis of the regional blood flow in the peripheral tissues, on the surface of the cerebral hemispheres, in the white and tumorous tissues along the length of the puncture canal was made by the method of surface and intratissue photoplethysmography. It was established that the optic properties of most tumors, cysts, and CSF spaces significantly differed from those of the white matter. Analysis of intratissue photoplethysmogram revealed considerable fluctuations of the pulsed blood flow in the white matter and tumorous tissue, reorganization of blood flow in the white matter and tumors was found in some cases counterphase to that on the surface of the cerebral hemispheres and in the peripheral tissues.

Brain Neoplasms↗
PubMed1995

Reactive astrocytes express substance-P immunoreactivity in the adult forebrain after injury.

Transformation of normal resting astrocytes to reactive astrocytes after injury is a well-known phenomenon. Using immunofluorescent labelling methods, astrocytes in the ischemically and retrogradely/anterogradely damaged adult forebrain nuclei were shown to express substance-P immunoreactivity. In contrast, astrocytes were not immunostained for substance-P in the normal brain or undamaged areas. Since substance-P has been shown to regulate inflammatory, wound-healing and immune responses in the peripheral tissues, it is likely that this aberrant expression of substance-P immunoreactivity in reactive astrocytes may relate to similar functions in the central nervous system as in the peripheral tissues after injury.

Animals↗
PubMed2002

LR white post-embedding colloidal gold method to immunostain MBP, P0, NF and S100 in glutaraldehyde fixed peripheral nerve tissue.

A variety of immunocytochemical techniques are now widely used for the electron and light microscopic examination of biological samples. They are employed routinely for investigating the role of certain proteins in nervous tissue. Immunoelectron microscopic studies require the tissue to be fixed and embedded in a solid support, which may disrupt cellular structures and destroy crucial antigens. A technique of post-embedding with LR white resin has been developed, and it has been shown that certain antigens tolerate fixation with glutaraldehyde. In this study, we optimized a previous post-embedding method using low-water-miscible low-temperature embedding resin (LR white) to immunostain MBP, P0, NF and S100 proteins in peripheral nerves fixed with a relatively high concentration of glutaraldehyde found to be compatible with the morphology of normally compacted nerve fibers from humans and adult animals. The main difference in the procedures described here from previous ones is the elimination of vibratome sectioning, rendering this immunostaining technique more accessible to neuropathological laboratories using standard equipment for the ultrastructural study of peripheral nerves. It may prove of value for localization and quantification of these proteins in normal and pathological conditions.

Animals↗
PubMed1995

Genomic structure and tissue distribution of the mouse dopamine D4 receptor.

The mouse dopamine D4 receptor gene was isolated from a genomic DNA library by plaque hybridization. The D4 receptor gene encoded an open reading frame consisting of 387 amino acids, interrupted by three introns. Distribution of the D4 receptor mRNA in brain regions and peripheral tissues of mice was examined by reverse transcription-polymerase chain reaction (RT-PCR). There was a remarkable expression of the receptor mRNA in various brain regions, showing the highest expression level in the cerebellum. Also, in the peripheral tissues a high level expression of the D4 mRNA was detected in the eye, adrenal gland and testes. We observed several differences in tissue distribution of the D4 mRNA in mice from that reported in other mammalian species.

Amino Acid Sequence↗
PubMed1997

The melanin-concentrating hormone gene in human: flanking region analysis, fine chromosome mapping, and tissue-specific expression.

Genomic sequences encoding the human melanin-concentrating hormone (MCH) were isolated from a YAC library and subcloned in pUC vector using a novel E. coli transformation method. A 4.1-kb fragment encompassing approximately 1.0 kb of the 5'-end-flanking region, the three exons-two introns of the coding region and approximately 1.7 kb of the 3'-end-flanking region, was sequenced. Comparison with the rat MCH gene indicated strong conservation in the 5'-flanking region, in particular over the putative TATA box, CAAT box, GRE and AP-1 elements that could potentially regulate MCH gene expression. FISH with a fluorescent MCH genomic probe on human chromosomes and PCR analysis of a YAC panel mapped MCH to chromosome 12q23.1 in a region flanked by D12S1074 and D12S1030 markers. Expression of the MCH RNA species and pro-MCH-derived peptides (MCH and NEI) was investigated in human tissues by combining Northern blotting, RT-PCR, in situ hybridization, immunohistochemistry and RIA. In the human brain, MCH mRNA and MCH/NEI peptides were predominantely expressed in the lateral hypothalamus in agreement with the known distribution of MCH expression in rat. In addition, MCH gene products were detected in extra-hypothalamic sites, such as the pallidum, neocortex and cerebellum. In peripheral tissues, MCH mRNA was identified in several organs, including the thymus, brown adipose tissue, duodenum and testis. An additional shorter MCH gene transcript, likely the result of alternate splicing, was revealed in several brain areas and peripheral tissues. While only fully processed MCH and NEI were found in hypothalamus, a different peptide form, bearing MCH and NEI epitopes, was detected in peripheral organs. This represents the first evidence for differential processing of pro-MCH in mammals.

Base Sequence↗
PubMed2003

The percentage of CD31+ T cells decreases after open but not laparoscopic surgery.

BACKGROUND: Efficient killing of tumor cells depends on T cells that migrate from the circulation to the peripheral tissues; these cells express CD31. This study was undertaken to determine the impact of open (OS) and laparoscopic (LS) colorectal surgery on the percentage of circulating CD3+CD31+ cells. METHODS: Peripheral blood was collected from 27 OS and 24 LS colon cancer patients preoperatively (preOP) and on postoperative days 1 (POD1) and 3 (POD3). CD31+ T cells were assessed by flow cytometry using monoclonal antibodies. RESULTS: In the OS group, the percentage of CD3+CD31+ cells was significantly lower in POD1 and POD3 samples compared to the preOP results. LS surgery did not result in a significant change in the percentage of these T cells. A significant correlation was found between the decrease in the percentage of CD3+CD31+ cells and the length of incision in OS patients. CONCLUSIONS: The percentage of CD3+CD31+ cells decreases following OS but not LS and may be related to incision length. This may compromise T cell function in the peripheral tissues in the postoperative period.

Adolescent↗
PubMed2005

Molecular cloning and mRNA profile of insulin-like growth factor type 1 receptor in orange-spotted grouper, Epinephelus coioides.

The insulin-like growth factor type 1 receptor (IGF-IR) belongs to the tyrosine kinase (TK) receptor family. Besides being mitogenic, IGF-IR plays a crucial role in cell survival, transformation and maintenance of the malignant phenotype. In this study, we cloned the cDNA from the hypothalamus of the orange-spotted grouper (Epinephelus coioides) using reverse transcription PCR (RT-PCR) and the rapid amplification of cDNA ends (RACE) method. The deduced amino acid sequence showed that the receptor comprises 1413 amino acid residues. It contains cysteine-rich domains in its alpha-subunit, and a conserved transmembrane domain and TK domains in its beta-subunit. Comparison of the amino acid sequence with those of other species showed that the grouper IGF-IR shares 90.2%, 89.6%, 71.9% and 72% similarity with the IGF-IR of the Japanese flounder, turbot, zebrafish-a and zebrafish-b, respectively. When compared with its mammalian homologue, grouper IGF-IR contains a large insertion at its C-terminus. Phylogenetic analysis has revealed that the grouper IGF-IR belongs to the b-type IGF-IRs and has a higher similarity with flounder and turbot IGF-IR, and a lower similarity (<70%) with human, mouse and avian IGF-IR. Grouper IGF-IR transcripts were detected in the brain, peripheral tissues, embryos and early development larvae by semi-quantitative RT-PCR assay. It was observed that IGF-IR mRNA expression was greater in the brain than in peripheral tissues. The level of IGF-IR mRNA expression was much higher in retina, gonad, skeletal muscle and gill tissues than in liver, heart and thymus tissues. The expression of IGF-IR can be visualized as a ubiquitous signal in unfertilized eggs, embryos and early development larvae. The distribution pattern of IGF-IR mRNA in grouper development suggests that IGF-IR plays an important role in the embryo and early larval development stages.

Amino Acid Sequence↗
PubMed2002

Metabolic lessons from genetically lean mice.

Different types of lean mice have been produced by genetic manipulation. Leanness can result from deficiency of stored energy or a lack of adipocytes to store the lipid. Mice lacking functional adipocytes are usually insulin resistant and have fatty livers, and elevated circulating triglyceride levels. Insulin resistance may result from the lack of adipocyte hormones (such as leptin) and increased metabolite (such as triglyceride) levels in nonadipose tissue. Mice with depleted adipocyte triglyceride levels typically are insulin sensitive and have normal or low liver and circulating triglycerides. Mechanisms to produce depleted adipocytes include increased energy expenditure by peripheral tissues, peripheral mechanisms to decrease food intake, and altered central regulation of these processes.

Adipocytes↗
PubMed1989

Aging alters the activity of 5'-deiodinase in the adenohypophysis, thyroid gland, and liver of the male rat.

Aging is characterized by a decreased secretion of thyroid hormones in rats associated with unchanged plasma TSH suggestive of impairments in the hypothalamo-pituitary-thyroid axis. Since it is known that pituitary T3 is more determinant on TSH secretion than plasma T3, we measured in young (4 months) and old (26 months) male rats the concentration of T3 in the anterior pituitary gland and found that it was similar in young and old animals despite the low circulating levels of thyroid hormones. This was suggestive of age-related differences in the intrapituitary T4 to T3 conversion. We therefore determined the activity of 5'-deiodinase (5'-D, type I and type II) in the adenohypophysis and investigated possible age-related changes in this enzyme activity in peripheral tissues by its determination in the thyroid gland and liver (type I) of young and old rats. Intrapituitary 5'-D activity was increased in old compared to young rats (type I 5'-D: 4.59 +/- 0.13 vs. 2.92 +/- 0.33 pmol rT3/h x mg protein; type II: 0.54 +/- 0.5 vs. 0.21 +/- 0.03 pmol rT3/h x mg protein; P less than 0.001). In contrast, in the thyroid gland and in the liver, type I 5'-D was reduced with age (4.7 +/- 0.6 vs. 7.4 +/- 0.8 and 3.1 +/- 0.4 vs. 5.6 +/- 0.5 nmol rT3/h x mg protein, respectively; P less than 0.01). These data are illustrative of age-related changes in the activity of 5'-D, different according to the tissues in agreement with the known tissue-specific regulation of the 5'-Ds. The reduced activity of 5'-D in the thyroid and liver of old rats is indicative of an impaired thyroid hormones disposal in peripheral tissues with age. In contrast, in the adenohypophysis of old rats, the increase in the activity of 5'-D is similar to that reported in hypothyroid animals and suggests the development with age of an adaptative mechanism in the presence of low circulating thyroid hormones; this mechanism leads to unchanged intrapituitary concentration of T3 and consequently to unaltered plasma levels of TSH in old rats.

Aging↗
PubMed2001

HIV in the brain: RNA levels and patterns of zidovudine resistance.

OBJECTIVE: To examine the association between HIV RNA levels, patterns of antiretroviral resistance, and neurologic status. METHODS: Autopsy samples from 13 HIV-infected subjects were examined for HIV-1 viral RNA (vRNA), and viral reverse transcriptase (RT) genotype was determined. All subjects had been clinically characterized using standard instruments before death. RESULTS: The median HIV-1 vRNA level in brain samples from subjects with moderate dementia was 7.79 log(10) copies/g (range 5.56 to 9.75 log(10) copies/g) compared with 5.44 log(10) copies/g (range 3.51 to 9.32 log(10) copies/g) for mildly demented subjects and 4.87 log(10) copies/g (3.51 to 6.86 log(10) copies/g) for those obtained from nondemented individuals. There were differences between subjects with moderate dementia and nondemented subjects (p = 0.0002) and between subjects with moderate and mild dementia (p = 0.0128). No significant differences among the groups were observed for vRNA levels in peripheral tissues. Some demented subjects had relatively low levels of HIV-1 vRNA, and paradoxically some nondemented subjects had high vRNA brain levels. Little subject effect in vRNA was noted in peripheral regions, but high regional variation in vRNA was noted within the brain. Patterns of the major zidovudine (ZDV) RT mutations in brain and peripheral tissues were concordant in most subjects. Subjects with longer duration of exposure to ZDV tended to have lower brain vRNA levels and a greater number of RT mutations than those with limited to no exposure. CONCLUSIONS: The presence and severity of HIV dementia correlates with the levels of productive HIV replication within the brain. Other pathophysiologic events (including macrophage activation) probably also contribute to neurologic dysfunction.

AIDS Dementia Complex↗
PubMed1955

Allergic neuritis: an experimental disease of rabbits induced by the injection of peripheral nervous tissue and adjuvants.

In experimental allergic encephalomyelitis (EAE), produced by injecting rabbits with whole rabbit spinal cord together with tubercle bacilli and mineral oil, lesions comparable to those seen in the central nervous system are found in the nerve roots, spinal ganglia, and peripheral nerves. When special fractions of bovine white matter are used as antigen in rabbits, the same distribution of lesions is seen but peripheral nerve involvement is relatively less frequent. When rabbit sciatic nerve or spinal ganglia are used as antigen in rabbits, lesions occur only in the roots, ganglia, and peripheral nerves. Lesions are not produced in the central nervous system, nor is there a meningitis. This disease picture has been called experimental allergic neuritis (EAN). The antigenicity of rabbit nerve is not impaired by autoclaving. Sciatic nerve of other mammalian species produces the same disease in rabbits as does rabbit nerve. Optic nerve, used as antigen, produces the typical picture of EAE, not EAN. The optic nerves are not affected in EAN, whereas they commonly contain lesions in EAE. There are differences of symptomatology, referable to the difference in distribution of lesions, between EAE and EAN. The spinal fluid of EAE shows an increase both in the number of cells and in the total protein content. In EAN, the same changes in protein are observed, but usually the cell count remains normal. The cell count appears to be related to the involvement of cerebral and spinal meninges, which is an almost invariable accompaniment of EAE. The skin tests and serologic studies made with homologous and heterologous antigens were essentially non-contributory, apparently as a consequence of the diversity of antigens present in the inoculated materials. The similarity between EAN and certain of the human polyneuritides is indicated and discussed.

Animals↗
PubMed1994

Electron microscopic observations of the relationship between peripheral nerve tissue proper and an endoneurial capillary in a dermal lesion of relapsed lepromatous patient.

The origin of relapse in clinically cured leprosy patients and the dissemination of Mycobacterium leprae in such patients are hitherto little understood phenomena. A detailed electron microscopical examination of a small dermal nerve in a lepromatous lesion of a presently relapsed patient was carried out. Our observations showed the presence of M. leprae in Schwann cells, perineurial cells, vacuolar spaces located in axoplasm and elsewhere. The course of a capillary, entering the endoneurium from the epineurium via the perineurium, suggested the possibility of hematogenous spread of M. leprae which had been tucked away in the dermal peripheral nerve. At the time of relapse, bacilli may multiply in the nerve, may enter the bloodstream, and thus disseminate from the nerve into other nerves and other tissues via hematogenous spread.

Humans↗