[Ambulatory and day surgery]

Ambulatory surgical care is intended to save healthcare expenditure from the economical viewpoint. From the patients point of view significant advantages as well as specific disadvantages of ambulatory surgery are known. The increase in the volume and complexity of procedures provided in an ambulatory setting are driven by improvements in anesthesia and surgical technique as well as by changes in financing and reimbursement. Therefore careful quality control and scientific evidence for the safety of increasingly used complex surgical procedures for higher risk patients is essential. Reducing the surgical trauma by minimally invasive surgical techniques and very good controllability by modern anesthesia concepts is making the management of the postoperative period crucial for successful ambulatory surgery. Most of the complications and common problems during the postoperative period, such as pain, nausea and vomiting, are not specific for ambulatory surgery, but management places an increasing burden of responsibility not only on general and specialised physicians, but also on other health professionals, patients, and family members.

Expression and regulation of osteopontin and connective tissue growth factor transcripts in rat anterior pituitary

Cell-cell interactions are important regulatory elements in anterior pituitary (AP) physiology. As model systems to study pituitary cell-cell interactions, AP cells kept either as monolayers or as organotypic reaggregate cultures were analyzed by differential display PCR. We identified six cDNA fragments (osteopontin (Opn), connective tissue growth factor (CTGF), alpha(v)-integrin, cathepsin H, lysozyme and O-acetyl GD(3) ganglioside synthase) that showed elevated expression in monolayers compared with reaggregate cultures and the AP. The adenohypophyseal mRNA expression of Opn and CTGF, two secreted signaling substances, was studied in more detail. In situ hybridization histochemistry revealed that Opn mRNA expression is restricted to a subpopulation of gonadotropes whereas CTGF hybridization signals could not be ascribed to any known cell type. Opn transcript levels were downregulated in the APs of lactating rats and decreased when rats received s.c. injections of 17beta-estradiol for 5 days. The mRNA expression was higher in male than in female rats and increased after gonadectomy. CTGF transcript levels were higher in male compared with female rats and were increased in pregnant rats and in rats treated for 5 days with triiodothyronine or dexamethasone. These results indicate that Opn and CTGF may be of physiological importance as local communication factors in the AP.

Sensitization to the behavioural effects of cocaine: alterations in tyrosine hydroxylase or endogenous opioid mRNAs are not necessarily involved

After repeated administration of cocaine at intervals, sensitization phenomena can be observed, so that its behavioural effects are enhanced. Since this phenomenon is long-lasting, it was of interest to study which persistent alterations in the activity of dopaminergic neurones or of endogenous opioid systems downstream of dopaminergic synapses in the basal ganglia are involved in the sensitization. Cocaine (10 mg/kg i.p.) was administered to rats on days 1, 3, 5 and 7 and saline on days 2, 4 and 6 ("repeated cocaine"), or saline was injected on days 1-6 and cocaine on day 7 ("acute cocaine"), or saline was injected on days 1-7 ("saline group"). The "repeated cocaine" schedule led to a significant sensitization to the locomotor activation produced by cocaine on day 7 or on day 17, 10 days after the end of sensitization protocol. Microdialysis in the nucleus accumbens which was performed after administration of cocaine (10 mg/kg i.p.) on day 7, or after an administration of the same dose 10 days after the last administration of cocaine, respectively, revealed significant acute increases of extracellular dopamine to about 200% of basal values. These increases were similar in "acute cocaine" and in "repeated cocaine" animals both after 7 days and after 17 days. For in situ hybridization studies, rats were sacrificed on day 7, 4.5 h after the last cocaine or saline administration. The mRNA for tyrosine hydroxylase (TH) in substantia nigra + ventral tegmental area was significantly elevated to about 140% of saline controls both in the "repeated cocaine" and the "acute cocaine" group as compared with the "saline group". In contrast, there were no differences between the three groups in the mRNAs of preprodynorphin or preproenkephalin levels measured in the nucleus accumbens (core and shell). These results suggest that sensitization phenomena to cocaine are not necessarily connected with alterations in the dopaminergic activity in the mesolimbic system or in the transcription of precursors of endogenous opioid peptides which are located downstream of the dopaminergic synapses.

Expression of thyrotropin-releasing hormone receptor 2 (TRH-R2) in the central nervous system of rats

The distribution of the recently discovered thyrotropin-releasing hormone (TRH) receptor subtype TRH-R2 was studied in rat brain, pituitary, and spinal cord by in situ hybridization histochemistry and compared with the distribution patterns of the other elements of TRH signaling, namely TRH, TRH-R1, and the TRH-degrading ectoenzyme (TRH-DE). In contrast to the very restricted mRNA expression of TRH-R1 in the central nervous system, TRH-R2 mRNA was widely distributed with highest transcript levels throughout the thalamus, in the cerebral and cerebellar cortex, medial habenulae, medial geniculate nucleus, pontine nuclei, and throughout the reticular formation. In accordance with the well-known endocrine function of TRH, TRH-R1 is found predominantly expressed in hypothalamic regions. Expression of TRH-R1 in various brainstem nuclei and spinal cord motoneurons seems to be associated with the described effects of TRH on the vegetative and autonomic system as well as on the somatomotor system. Furthermore, the fully complementary expression of both receptor subtypes, even in regions where transcripts for both receptors were found (e.g., medial septum, lateral hypothalamus superior colliculi, substantia nigra, etc.), indicates that in discrete neuroanatomical pathways the two receptors serve highly specific functions for the transmission of TRH signals. Together with TRH-DE, the putative terminator of TRH actions that shows in various, but not all, brain areas, an overlapping mRNA distribution pattern with both receptors, the distribution of TRH-R2 mRNA seems to provide the anatomical basis for the described effects of TRH on higher cognitive functions as well as its effect on arousal, locomotor activity, and pain perception.

Targeted infection of endothelial cells by avian influenza virus A/FPV/Rostock/34 (H7N1) in chicken embryos

The tissue tropism and spread of infection of the highly pathogenic avian influenza virus A/FPV/Rostock/34 (H7N1) (FPV) were analyzed in 11-day-old chicken embryos. As shown by in situ hybridization, the virus caused generalized infection that was strictly confined to endothelial cells in all organs. Studies with reassortants of FPV and the apathogenic avian strain A/chick/Germany/N/49 (H10N7) revealed that endotheliotropism was linked to FPV hemagglutinin (HA). To further analyze the factors determining endotheliotropism, the HA-activating protease furin was cloned from chicken tissue. Ubiquitous expression of furin and other proprotein convertases in the chick embryo indicated that proteolytic activation of HA was not responsible for restriction of infection to the endothelium. To determine the expression of virus receptors in embryonic tissues, histochemical analysis of alpha2,3- and alpha2,6-linked neuraminic acid was carried out by lectin-binding assays. These receptors were found on endothelial cells and on several epithelial cells, but not on tissues surrounding endothelia. Finally, we analyzed the polarity of virus maturation in endothelial cells. Studies on cultured human endothelial cells employing confocal laser scanning microscopy revealed that HA is specifically targeted to the apical surface of these cells, and electron microscopy of embryonic tissues showed that virus maturation occurs also at the luminar side. Taken together, these observations indicate that endotheliotropism of FPV in the chicken embryo is determined, on one hand, by the high cleavability of HA, which mediates virus entry into the vascular system, and, on the other hand, by restricted receptor expression and polar budding, which prevent spread of infection into tissues surrounding endothelia.

Somatomotor neuron-specific expression of the human cholinergic gene locus in transgenic mice

We examined the expression pattern of the vesicular acetylcholine transporter in the mouse nervous system, using rodent-specific riboprobes and antibodies, prior to comparing it with the distribution of vesicular acetylcholine transporter expressed from a human transgene in the mouse, using riboprobes and antibodies specific for human. Endogenous vesicular acetylcholine transporter expression was high in spinal and brainstem somatomotor neurons, vagal visceromotor neurons, and postganglionic parasympathetic neurons, moderate in basal forebrain and brainstem projection neurons and striatal interneurons, and low in intestinal intrinsic neurons. Vesicular acetylcholine transporter expression in intrinsic cortical neurons was restricted to the entorhinal cortex. The sequence of the mouse cholinergic gene locus to 5.1kb upstream of the start of transcription of the vesicular acetylcholine transporter gene was determined and compared with the corresponding region of the human gene. Cis-regulatory domains implicated previously in human or rat cholinergic gene regulation are highly conserved in mouse, indicating their probable relevance to the regulation of the mammalian cholinergic gene locus in vivo. Mouse lines were established containing a human transgene that included the vesicular acetylcholine transporter gene and sequences spanning 5kb upstream and 1.8kb downstream of the vesicular acetylcholine transporter open reading frame. In this transgene, the intact human vesicular acetylcholine transporter was able to act as its own reporter. This allowed elements within the vesicular acetylcholine transporter open reading frame itself, shown previously to affect transcription in vitro, to be assessed in vivo with antibodies and riboprobes that reliably distinguished between human and mouse vesicular acetylcholine transporters and their messenger RNAs. Expression of the human vesicular acetylcholine transporter was restricted to mouse cholinergic somatomotor neurons in the spinal cord and brainstem, but absent from other central and peripheral cholinergic neurons. The mouse appears to be an appropriate model for the study of the genetic regulation of the cholinergic gene locus, and the physiology and neurochemistry of the mammalian cholinergic nervous system, although differences exist in the distribution of cortical cholinergic neurons between the mouse and other mammals. The somatomotor neuron-specific expression pattern of the transgenic human vesicular acetylcholine transporter suggests a mosaic model for cholinergic gene locus regulation in separate subdivisions of the mammalian cholinergic nervous system.

Complement C1q is dramatically up-regulated in brain microglia in response to transient global cerebral ischemia

Recent evidence suggests that the pathophysiology of neurodegenerative and inflammatory neurological diseases has a neuroimmunological component involving complement, an innate humoral immune defense system. The present study demonstrates the effects of experimentally induced global ischemia on the biosynthesis of C1q, the recognition subcomponent of the classical complement activation pathway, in the CNS. Using semiquantitative in situ hybridization, immunohistochemistry, and confocal laser scanning microscopy, a dramatic and widespread increase of C1q biosynthesis in rat brain microglia (but not in astrocytes or neurons) within 24 h after the ischemic insult was observed. A marked increase of C1q functional activity in cerebrospinal fluid taken 1, 24, and 72 h after the ischemic insult was determined by C1q-dependent hemolytic assay. In the light of the well-established role of complement and complement activation products in the initiation and maintenance of inflammation, the ischemia-induced increase of cerebral C1q biosynthesis and of C1q functional activity in the cerebrospinal fluid implies that the proinflammatory activities of locally produced complement are likely to contribute to the pathophysiology of cerebral ischemia. Pharmacological modulation of complement activation in the brain may be a therapeutic target in the treatment of stroke.

[Specific dimensions of anxiety in surgical patients. Development of a questionnaire and empirical results]

This article reports on the construction and empirical evaluation of an instrument for the measurement of different components of surgery-related state anxiety. The anxiety inventory KASA identifies three components: cognitive, autonomic, and somatic anxiety reactions. Internal consistencies of the three scales related to these components were highly satisfactory (Cronbach's alpha between 0.80 and 0.91). An analysis of scores of these three components across the perioperative period demonstrates that the KASA is a sensitive indicator of state anxiety changes. Further analyses concerning external relationships of this new instrument with indicators of coping, trait anxiety, perioperative mood states and postoperative adjustment are reported. Results of these analyses indicate that the KASA is a reliable and valid measure of different components of surgery-related anxiety.

Thyrotropin-releasing hormone (TRH), a signal peptide of the central nervous system

Thyrotropin-Releasing Hormone (TRH; pyroGlu-His-Pro-NH2), originally isolated as a hypothalamic neuropeptide hormone, most likely acts also as a neuromodulator and/or neurotransmitter in the central nervous system (CNS). This interpretation is supported by the identification of a peptidase localized on the surface of neuronal cells which has been termed TRH-degrading ectoenzyme (TRH-DE) since it selectively inactivates TRH. Vice versa it also holds true that TRH is selectively inactivated only by TRH-DE and thus, this enzyme might be considered to be the terminator of TRH signals. In situ-hybridization histochemistry was used to study the TRHergic communication system by analyzing the gene expression of TRH-DE in relation to TRH and to the TRH receptors (TRH-R1 and TRH-R2). TRH mRNA is highly expressed in "thyrotropic" hypothalamic regions and in some selected brain areas. For TRH-R1 and TRH-R2, an almost exclusive mRNA distribution pattern was noticed in many brain regions. Interestingly, a widespread distribution of TRH-DE predominantly in neo- and allocortical regions was observed essentially overlapping the distribution patterns of TRH-R1 and TRH-R2. These data support the hypothesis that TRH-DE is important in the TRH-mediated modulation of sensory, locomotor and cognitive functions of the CNS and could be considered to be a marker to map TRHergic pathways.

Expression of vesicular monoamine transporters in endocrine hyperplasia and endocrine tumors of the oxyntic stomach

BACKGROUND

Gastric enterochromaffin-like (ECL) cells selectively express the vesicular monoamine transporter (VMAT) VMAT2, and enterochromaffin (EC) cells the VMAT1 isoform.

AIMS

We investigated whether VMAT isoform selection indicates the origin of endocrine hyperplasia and neoplasia from oxyntic ECL or EC cells and may be of prognostic significance in different types of gastric carcinoids.

METHODS

Tissue from patients with chronic atrophic gastritis (CAG), Zollinger-Ellison-syndrome (ZES), gastric carcinoids and neuroendocrine carcinoma (NEC) was investigated by immunohistology and in situ hybridization.

RESULTS

Endocrine cells forming diffuse, linear, and micronodular hyperplasia in CAG and ZES, as well as oxyntic microcarcinoids expressed both VMAT2 and chromogranin A (CgA) but neither VMAT1 nor serotonin. In five of six sporadic carcinoids VMAT2 and CgA but not VMAT1 were detected. One carcinoid was copositive for VMAT1 and serotonin but negative for VMAT2. Electron microscopy confirmed the VMAT2-positive tumors as ECLoma and the VMAT1-immunoreactive carcinoid as EComa.

CONCLUSIONS

VMAT2 and VMAT1 are reliable markers for differentiation of gastric endocrine hyperplasia and neoplasia from ECL and EC cells, respectively. The significance of VMAT2 and VMAT1 as prognostic markers lies in the relatively poor prognosis for EComa compared to ECLoma, characterized by VMAT2 positivity. The absence of both VMAT2 and VMAT1 in NEC may indicate poor prognosis.

Calcitonin gene-related peptide gene expression in collagen-induced arthritis is differentially regulated in primary afferents and motoneurons: influence of glucocorticoids

Calcitonin gene-related peptide is involved in peripheral and spinal mechanisms of inflammatory pain. In this paper, we used collagen II-induced arthritis in the rat as a model to investigate the influence of chronic arthritic pain on calcitonin gene-related peptide gene expression in sensory and motor pathways. Additionally, we examined the effect of the glucocorticoid drug budesonide on arthritis-induced changes of calcitonin gene-related peptide expression and constitutive calcitonin gene-related peptide expression. Thirteen days after the immunization with native rat collagen type II rats developed a progressive and chronic polyarthritis which was scored with respect to the degree of swelling and/or redness of the paw and ankle joints. Budesonide significantly attenuated the extent of arthritis. Changes in calcitonin gene-related peptide expression were evaluated by semiquantitative in situ hybridization and immunocytochemistry on day 21 post-immunization. In sensory neurons of dorsal root ganglia of arthritic rats, a significant increase in calcitonin gene-related peptide messenger RNA and protein levels was seen. These increases were completely blocked by budesonide. Also in dorsal root ganglia of non-arthritic rats, budesonide had an effect, with reduced calcitonin gene-related peptide messenger RNA levels below constitutive concentrations. Image analysis of calcitonin gene-related peptide immunoreactivity revealed that changes in calcitonin gene-related peptide expression were due to alterations in calcitonin gene-related peptide expression levels rather than to de novo synthesis or changes in the numbers of calcitonin gene-related peptide expressing neurons. In spinal motoneurons of arthritic rats, marked decreases in calcitonin gene-related peptide messenger RNA and protein levels were measured. These reductions were attenuated by budesonide. The changes in calcitonin gene-related peptide expression in motoneurons correlated with the severity of arthritis in the ipsilateral hind paw. Budesonide had no effects on calcitonin gene-related peptide messenger RNA levels in motoneurons of non-arthritic rats. The opposite regulation of calcitonin gene-related peptide gene expression in primary sensory and spinal somatomotor pathways in collagen-induced arthritis suggests that calcitonin gene-related peptide plays a specific role in both chronic inflammatory pain and arthritis-induced motor dysfunction. The sensitivity of constitutive and inflammation-induced sensory calcitonin gene-related peptide expression to budesonide treatment may indicate that the beneficial effects of steroid treatment in inflammation is partly mediated by down-regulation of calcitonin gene-related peptide in sensory neurons involved in neurogenic inflammation.

Clenbuterol induces growth factor mRNA, activates astrocytes, and protects rat brain tissue against ischemic damage

The induction of growth factor synthesis in brain tissue by beta2-adrenoceptor agonists, such as clenbuterol, is a promising approach to protect brain tissue from ischemic damage. Clenbuterol (0.01-0.5 mg/kg) reduced the cortical infarct volume in Long-Evans rats as measured 7 days after permanent occlusion of the middle cerebral artery. Dosages of clenbuterol higher than 1 mg/kg showed no cerebroprotective effect due to a decrease in blood pressure and an increase in plasma glucose level. The increase in the mRNA level of nerve growth factor (NGF), basic fibroblast growth factor (basic FGF), and transforming growth factor-beta1 (TGF-beta1) mRNA in cortical and hippocampal tissue occurred earlier after middle cerebral artery occlusion and was more pronounced in animals treated with clenbuterol than in controls. In addition, glial fibrillary acidic protein (GFAP) mRNA expression was enhanced in astrocytes 6 h after ischemia in clenbuterol-treated animals. The results suggest that growth factor synthesis is enhanced in activated astrocytes and that this could be the mechanism of clenbuterol-induced cerebroprotection after ischemia.

[Hemodynamic effects of a ventriculo-cisternal perfusion of bupivacaine]

OBJECTIVES

The cardiotoxic properties of bupivacain have been well documented under in-vitro, as well as under in-vivo conditions. A further mechanism of cardiovascular impairment by bupivacaine via the central nervous system gained investigational interest in animal studies. The aim of our study was to demonstrate the effect of a ventriculocisternal perfusion of bupivacain on systemic hemodynamic variables and their reversibility by wash-out with mock-CSF.

METHODS

After obtaining animal investional committee consent, nine anaesthetized and relaxed pigs were prepared for a ventriculocisternal perfusion (VCP). Hemodynamic data were obtained by invasive blood pressure measurements in the high and low pressure system as well as cardiac output (thermodilution technique), intracranial pressure and electrocardiogram. Systemic vascular resistance and stroke volume were calculated using standard formulas. A second group of three animals were exposed to an intravenous infusion of the same dose of bupivacain over the same period of time to rule out direct cardiac effects. After instrumentation baseline data were obtained (K0 1) under VCP with mock-CSF for 30 minutes. The mock-CSF was replaced by 0.05% bupivacaine in mock-CSF and VCP was continued with 3 ml.h-1 for 20 minutes. After administration of 500 micrograms bupivacaine data were collected (BU). The bupivacaine solution was replaced by mock-CSF and after twenty minutes hemodynamic measurement were repeated (K02).

RESULTS

The intravenous administration of 500 micrograms bupivacaine had no effect on all measured variables. VCP of the same dose resulted in significant increase in heart rate, systolic, diastolic and mean arterial blood pressures. Left and right heart filling pressures as well as systemic vascular resistance were not affected while the stroke volume decreased. After continuation of VCP with mock-CSF hemodynamic changes were reversed.

DISCUSSION

Our results demonstrate that bupivacaine initiates an indirect cardiovascular stimulating effect of a VCP with 500 micrograms of bupivacaine via the central nervous system. The intravenous administration of the same dose had no effect. The centrally mediated cardiovascular effect of bupivacaine was reversed by wash-out with mock-CSF. The cardiovascular stimulation observed in this animal experiment may be of clinical relevance as a potential sign of toxic effects of bupivacaine on the CNS.

Neuronal expression of fractalkine in the presence and absence of inflammation

Fractalkine is the only as yet known member of a novel class of chemokines. Besides its novel Cys-X-X-X-Cys motif, fractalkine exhibits features which have not been described for any other member of the chemokine family, including its unusual size (397 amino acids human, 395 mouse) and the possession of a transmembrane anchor, from which a soluble form may be released by extracellular cleavage. This report demonstrates the abundant mRNA and fractalkine protein expression in neuronal cells. The neuronal expression of fractalkine mRNA is unaffected by experimentally induced inflammation of central nervous tissue.

The thyrotropin-releasing hormone-degrading ectoenzyme: the third element of the thyrotropin-releasing hormone-signaling system

The peptidergic signal substance thyrotropin-releasing hormone (TRH) is inactivated by the TRH-degrading ectoenzyme (TRH-DE), a peptidase that exhibits an extraordinary high degree of substrate specificity and other unusual characteristics. There is no other ectopeptidase known capable of degrading this tripeptideamide, and vice versa, TRH is the only known substrate of this unique enzyme. Thus, studies on this enzyme may reveal new aspects on the function of the TRH signaling system. After succeeding in purifying this enzyme to homogeneity and cloning the cDNA encoding rat TRH-DE, molecular tools became available to study the expression of this enzyme by Northern blot analysis and in situ hybridization histochemistry. The stringent and tissue-specific regulation of the adenohypophyseal TRH-DE by estradiol and thyroid hormones strongly suggests that this enzyme may act as a regulatory element modulating pituitary hormone secretion. In brain, the expression of TRH-DE is not influenced by peripheral hormones but the distinct distribution pattern, and the high activities support the concept that in this tissue TRH-DE may act as a terminator of TRH signals.

From the cholinergic gene locus to the cholinergic neuron

The cholinergic gene locus (CGL) was first identified in 1994 as the site (human chromosome 10q11.2) at which choline acetyltransferase and a functional vesicular acetylcholine transporter are co-localized. Here, we present recent neuroanatomical, developmental, and evolutionary insights into the chemical coding of cholinergic neurotransmission that have been gleaned from the study of the CGL, and its protein products VAChT and ChAT, which comprise a synthesis-sequestration pathway that functionally defines the cholinergic phenotype.

Cholinergic neurons and terminal fields revealed by immunohistochemistry for the vesicular acetylcholine transporter. I. Central nervous system

Antibodies directed against the C-terminus of the rat vesicular acetylcholine transporter mark expression of this specifically cholinergic protein in perinuclear regions of the soma and on secretory vesicles concentrated within cholinergic nerve terminals. In the central nervous system, the vesicular acetylcholine transporter terminal fields of the major putative cholinergic pathways in cortex, hippocampus, thalamus, amygdala, olfactory cortex and interpeduncular nucleus were examined and characterized. The existence of an intrinsic cholinergic innervation of cerebral cortex was confirmed by both in situ hybridization histochemistry and immunohistochemistry for the rat vesicular acetylcholine transporter and choline acetyltransferase. Cholinergic interneurons of the olfactory tubercle and Islands of Calleja, and the major intrinsic cholinergic innervation of striatum were fully characterized at the light microscopic level with vesicular acetylcholine transporter immunohistochemistry. Cholinergic staining was much more extensive for the vesicular acetylcholine transporter than for choline acetyltransferase in all these regions, due to visualization of cholinergic nerve terminals not easily seen with immunohistochemistry for choline acetyltransferase in paraffin-embedded sections. Cholinergic innervation of the median eminence of the hypothalamus, previously observed with vesicular acetylcholine transporter immunohistochemistry, was confirmed by the presence of vesicular acetylcholine transporter immunoreactivity in extracts of median eminence by western blotting. Cholinergic projections to cerebellum, pineal gland, and to the substantia nigra were documented by vesicular acetylcholine transporter-positive punctate staining in these structures. Additional novel localizations of putative cholinergic terminals to the subependymal zone surrounding the lateral ventricles, and putative cholinergic cell bodies in the sensory mesencephalic trigeminal nucleus, a primary sensory afferent ganglion located in the brainstem, are documented here. The cholinergic phenotype of neurons of the sensory mesencephalic trigeminal nucleus was confirmed by choline acetyltransferase immunohistochemistry. A feature of cholinergic neurons of the central nervous system revealed clearly with vesicular acetylcholine transporter immunohistochemistry in paraffin-embedded sections is the termination of cholinergic neurons on cholinergic cell bodies. These are most prominent on motor neurons of the spinal cord, less prominent but present in some brainstem motor nuclei, and apparently absent from projection neurons of the telencephalon and brainstem, as well as from the preganglionic vesicular acetylcholine transporter-positive sympathetic and parasympathetic neurons visualized in the intermediolateral and intermediomedial columns of the spinal cord. In addition to the large puncta decorating motor neuronal perikarya and dendrites in the ventral horn, vesicular acetylcholine transporter-positive terminal fields are distributed in lamina X surrounding the central canal, where additional small vesicular acetylcholine transporter-positive cell bodies are located, and in the superficial layers of the dorsal horn. Components of the central cholinergic nervous system whose existence has been controversial have been confirmed, and the existence of new components documented, with immunohistochemistry for the vesicular acetylcholine transporter. Quantitative visualization of terminal fields of known cholinergic systems by staining for vesicular acetylcholine transporter will expand the possibilities for documenting changes in synaptic patency accompanying physiological and pathophysiological changes in these systems.

Cholinergic neurons and terminal fields revealed by immunohistochemistry for the vesicular acetylcholine transporter. II. The peripheral nervous system

The peripheral sympathetic and parasympathetic cholinergic innervation was investigated with antibodies directed against the C-terminus of the rat vesicular acetylcholine transporter. Immunohistochemistry for the vesicular acetylcholine transporter resulted in considerably more detailed visualization of cholinergic terminal fields in the peripheral nervous system than reported previously and was well suited to also identify cholinergic perikarya. Vesicular acetylcholine transporter immunoreactivity completely delineated the preganglionic sympathetic terminals in pre- and paravertebral sympathetic ganglia, and in the adrenal medulla as well as postganglionic cholinergic neurons in the paravertebral chain. Cholinergic terminals of sudomotor and vasomotor nerves of skeletal muscle were optimally visualized. Mixed peripheral ganglia, including periprostatic and uterovaginal ganglia, exhibited extensive preganglionic cholinergic innervation of both noradrenergic and cholinergic postganglionic principal neurons which were intermingled in these ganglia. Varicose vesicular acetylcholine transporter-positive fibres and terminals, representing the cranial parasympathetic innervation of the cerebral vasculature, of salivary and lacrimal glands, of the eye, of the respiratory tract and of the upper digestive tract innervated various target structures including seromucous gland epithelium and myoepithelium, respiratory epithelium, and smooth muscle of the tracheobronchial tree. The only macrovascular elements receiving vesicular acetylcholine transporter-positive innervation were the cerebral arteries. The microvasculature throughout the viscera, with the exception of lymphoid tissues, the liver and kidney, received vesicular acetylcholine transporter-positive innervation while the microvasculature of limb and trunk skeletal muscle appeared to be the only relevant somatic target of vesicular acetylcholine transporter innervation. Vesicular acetylcholine transporter immunoreactivity was particularly useful for identification of parasympathetic intrinsic ganglia, and their terminal fields, in heart, uterus, and other peripheral organs receiving parasympathetic innervation. Extensive vesicular acetylcholine transporter-positive terminal fields were apparent in both atrial and ventricular tissues of the heart targeting cardiomyocytes as well as cardiac microvessels. Pericardiac brown adipose tissue was also supplied by vesicular acetylcholine transporter-positive varicose fibres. The enteric ganglia of the myenteric and submucous plexus, their synaptic junctions with circular and longitudinal smooth muscle, and terminal fields of the lamina propria of the stomach and intestine and of the local microvasculature were intensely vesicular acetylcholine transporter positive. Vesicular acetylcholine transporter-positive innervation was delivered to the exocrine and endocrine pancreas originating from vesicular acetylcholine transporter-positive intrapancreatic ganglia. Vesicular acetylcholine transporter immunoreactivity in urogenital organs revealed the patterns of terminal cholinergic fields arising from the sacral parasympathetic innervation of these structures. Components of the cholinergic nervous system in the periphery whose existence has been controversial have been confirmed, and the existence of new components of the cholinergic nervous system has been documented, with vesicular acetylcholine transporter immunohistochemistry. Visualization of vesicular acetylcholine transporter will allow documentation of changes in synaptic patency during development, in disease, and during changes in neurotransmission accompanying injury and dystrophy, in the peripheral nervous system.

Region-specific expression of thyrotrophin-releasing hormone-degrading ectoenzyme in the rat central nervous system and pituitary gland

Thyrotrophin-releasing hormone (TRH), a hypothalamic neuropeptide hormone and a putative neuromodulator/ neurotransmitter in the central nervous system is inactivated by the TRH-degrading ectoenzyme (TRH-DE), a TRH-specific metallopeptidase localized on the surface of neuronal brain cells in culture and on lactotrophic cells of the pituitary. After succeeding in cloning the cDNA of TRH-DE we now report on the cellular distribution pattern of this enzyme in rat brain, spinal cord and pituitary gland using in situ hybridization histochemistry. In the pituitary, TRH-DE mRNA was found both in the anterior and the neural lobe but not in the intermediate lobe. After treatment with triiodothyronine (T3) a dramatic increase in the mRNA levels of the TRH-DE and a decrease in the intensity of the TRH receptor could be observed in the anterior lobe of the pituitary. In brain, TRH-DE transcripts were predominantly found in neo- and allocortical regions with strongest signals in the olfactory bulb, the piriform cortex, the cerebral cortex, the granular layer of the cerebellar cortex and the pyramidal cells of the Ammon's horn. In the diencephalon, the highest TRH-DE mRNA levels were observed in the medial habenulae followed by several hypothalamic subregions. In the mesencephalon and brainstem, moderate signals were present in the superior colliculi, substantia nigra, dorsal raphe and in the periolivar region. In the spinal cord, TRH-DE mRNA positive neurons were present in all layers. The very distinct distribution of TRH-DE in the brain and the hormonal regulation of the adenohypophyseal enzyme support the concept that this peptidase serves very specialized functions.

Vesicular amine transporter expression and isoform selection in developing brain, peripheral nervous system and gut

The vesicular monoamine transporters VMAT1 and VMAT2 are essential components of monoaminergic neurons and endocrine cells whose expression in development may provide insight into lineage pathways for chemical coding in the diffuse neuroendocrine system. Thus, the brain is a compartment in which only monoaminergic neurons are generated, the gut epithelium generates only endocrine monoamine-containing cells, and the neural crest produces both autonomic monoaminergic neurons and endocrine/paracrine monoaminergic cells. Selection of either the VMAT1 or VMAT2 isoform was examined in these three compartments during development. In the central nervous system VMAT2, but not VMAT1, was expressed in neuroepithelial cells by embryonic day 12 (E12), and all major monoaminergic cell groups by E14. Thalamocortical and hypothalamic neurons that do not express VMAT2 in adulthood were transiently VMAT2-positive from E16 to postnatal day 6 (P6). EC cells of the gut expressed exclusively VMAT1 from E19 on, while histamine-containing enterochromaffin-like (ECL) cells of the stomach expressed only VMAT2 by E19 and throughout postnatal development. VMAT2 and the vesicular acetylcholine transporter VAChT were co-expressed in early development of the primary sympathetic chain as well as in the cranial parasympathetic ganglia. VAChT was progressively restricted to a small population of VMAT2-negative post-ganglionic neurons in the adult sympathetic chain, while VMAT2 expression persisted in sympathetic principal ganglion and SIF cells but was eventually extinguished in cranial parasympathetic ganglia. VMAT1 was co-expressed with VAChT and VMAT2 mRNA in the primary sympathetic chain on E12, but progressively restricted to small intensely fluorescent (SIF) and chromaffin cells thereafter. Thus, expression of the vesicular amine transporters appropriate for chemical coding of brain neurons and gut endocrine cells are pre-determined developmentally. In contrast, the neural crest-derived sympathoadrenal and neural crest-derived parasympathetic cell groups examined here initially co-express two or more vesicular amine transporters, followed by extinction of the inappropriate transporter(s) later in development. Some neural crest-derived neuroendocrine cell populations continue to express both isoforms of VMAT even in adulthood. Lineage distinctions in ontogeny of vesicular amine transporter expression in brain, gut and autonomic nervous system make it likely that the same genes are regulated differently in the autonomic nervous system compared to brain and gut.

Cutaneous Merkel cells of the rat contain both dynorphin A and vesicular monoamine transporter type 1 (VMAT1) immunoreactivity

To delineate fully opioid peptide function in cutaneous inflammatory and nociceptive responses, it is necessary to know first which opioid peptides are present in the skin and which cellular elements in the skin store and secrete them. Merkel cells are cutaneous neuroendocrine cells, which may derive from the neural crest or from undifferentiated keratinocytes with stem cell character. The neuroendocrine character of Merkel cells is supported by their immunoreactivity for chromogranin A (CGA) and a variety of neuropeptides, among them the opioid peptide [Met]enkephalin as shown in guinea-pig and mouse. This study investigates in the rat whether the preprodynorphin derived opioid peptide dynorphin A is expressed in cutaneous Merkel cells and possibly related to an aminergic phenotype. Light microscopic immunohistochemistry revealed dynorphin A immunoreactivity in Merkel cells to be codistributed with immunoreactivity for calcitonin gene-related peptide (CGRP) and CGA, two well-established merker peptides of mammalian Merkel cells. Vibrissal Merkel cells stained for the neuroendocrine vesicular monoamine transporter isoform 1 (VMAT1) but not for the predominantly neuronal isoform 2 (VMAT2). Merkel cell staining for dynorphin A, VMAT1, CGA, and CGRP was unaffected by experimental denervation. Dynorphin A and a still unidentified monoamine, possibly serotonin, may cofunction as autocrine or paracrine mediators in the mechanosensory Merkel cell--axon complex and are potentially involved in peripheral analgesia.

Upstream sequencing and functional characterization of the human cholinergic gene locus

The 5' flanking region of the human VAChT gene was sequenced to approx 5350 bases upstream of the initiating methionine codon of the VAChT open reading frame (orf). The 5' flanks of the human and rat cholinergic gene loci were compared to identify regions of local sequence conservation, and therefore of potential regulatory importance. Several discrete domains of high homology, including a cluster of far-upstream cis-active consensus motifs, a neuronally restrictive silencer element consensus sequence, and additional conserved sequences within the putative nerve growth factor response domain of the locus, were identified. The probable start of transcription of the VAChT gene was deduced from mapping of sequences of rat and human VAChT cDNAs onto the 5' flanking regions of the human and rat cholinergic gene loci. The actual utilization of a putative 5' VAChT exon in rat central nervous system (CNS) tissue was assessed by in situ hybridization histochemistry. RNA transcripts containing both VAChT and ChAT protein-coding sequences were abundant in spinal cord motoneurons, sympathetic preganglionic cells, basal forebrain, striatum, and cranial motor nuclei. R-exon-containing transcripts could be detected only at low levels in these cell groups, implying that most transcription of VAChT proceeds from a promoter downstream of the R-exon. To assess the structural requirements for expression of the VAChT gene without bias regarding the actual start of transcription, a 5' fragment of the human gene corresponding to approximately 3 kb of sequence extending upstream from within the presumed 5' untranslated region of VAChT itself was fused to a luciferase-encoding reporter and transfected into VAChT-expressing and nonexpressing human and rat cell lines. This portion of the VAChT gene provided strong promoter expression in both cholinergic and noncholinergic cell lines. Deletion of the putative neuronally restrictive silencer element (NRSE) resulted in enhanced transcription in all cell lines. Lack of differential expression of VAChT transcription in VAChT-expressing vs non-VAChT-expressing cell lines suggested that additional enhancer elements controlling cell-specific expression of the VAChT gene exist further upstream in the cholinergic locus 5' flank. Conservation of potential cis-active elements within a 1.4 kb sequence immediately upstream of the NRSE in both rat and human cholinergic gene loci suggests that this domain is required for cholinergic-specific regulation of VAChT and ChAT gene transcription.

Properdin, a positive regulator of complement activation, is released from secondary granules of stimulated peripheral blood neutrophils

Properdin is an important regulatory constituent of the complement system. In contrast to most other components of complement, biosynthesis of properdin is restricted to a few cell types only, i.e., monocytes/macrophages and peripheral blood T cells. This report demonstrates the presence of properdin mRNA in peripheral blood granulocytes and shows that properdin is stored in the granules of human neutrophils and secreted upon stimulation with TNF-alpha, C5a, IL-8, or FMLP. Subcellular fractionation using Percoll density gradients and Western blot analyses revealed that the bulk of properdin is contained in the secondary granules. Moreover, flow cytometric analyses indicated that properdin is present on the surface of neutrophils. In contrast to alternative pathway components, components of the classical pathway of complement activation, such as C2 and C4, were not detected. Our findings suggest that neutrophils can actively stabilize and amplify the alternative activation pathway of complement by secretion of properdin as part of the innate defense against microorganisms.

Properdin, a positive regulator of complement activation, is released from secondary granules of stimulated peripheral blood neutrophils

Properdin is an important regulatory constituent of the complement system. In contrast to most other components of complement, biosynthesis of properdin is restricted to a few cell types only, i.e., monocytes/macrophages and peripheral blood T cells. This report demonstrates the presence of properdin mRNA in peripheral blood granulocytes and shows that properdin is stored in the granules of human neutrophils and secreted upon stimulation with TNF-alpha, C5a, IL-8, or FMLP. Subcellular fractionation using Percoll density gradients and Western blot analyses revealed that the bulk of properdin is contained in the secondary granules. Moreover, flow cytometric analyses indicated that properdin is present on the surface of neutrophils. In contrast to alternative pathway components, components of the classical pathway of complement activation, such as C2 and C4, were not detected. Our findings suggest that neutrophils can actively stabilize and amplify the alternative activation pathway of complement by secretion of properdin as part of the innate defense against microorganisms.

Target-independent cholinergic differentiation in the rat sympathetic nervous system

Chemical coding in the sympathetic nervous system involves both noradrenergic and, for a minority of neurons, cholinergic neurotransmission. The expression of the cholinergic phenotype in the developing sympathetic nervous system was examined to determine if coding for cholinergic transmission occurs before or after innervation of peripheral target organs. The vesicular acetylcholine transporter (VAChT) and choline acetyltransferase, the products of the "cholinergic gene locus" determining the cholinergic phenotype, were expressed in principal cells of the paravertebral, but only rarely in prevertebral, sympathetic chains as early as embryonic day 14. A subpopulation of VAChT- and choline acetyltransferase-positive sympathetic ganglion cells persisted throughout development of the stellate and more caudal paravertebral ganglia into anatomically distinct cell groups, and into adulthood. The forepaw eccrine sweat glands, innervated exclusively by the stellate ganglion, received VAChT-positive nerve terminals at least as early as postembryonic day 4, coincident with the development of the sweat glands themselves. These terminals, like the VAChT-positive cell bodies of the developing stellate ganglion, have some noradrenergic traits including expression of tyrosine hydroxylase, but did not express the vesicular monoamine transporter, and are therefore not functionally noradrenergic. Development of the cholinergic phenotype in principal cells of the sympathetic paravertebral ganglia apparently occurs via receipt of instructive cues, or selection, within the sympathetic chain itself or perhaps even during migration of the cells of the neural crest from which the paravertebral ganglia arise.

Immunohistochemical localization of the pro-peptide processing enzymes PC1/PC3 and PC2 in the human anal canal

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 subpopulation of squamous cells. Enteric neurons were PC2 immunoreactive, whereas PC2 immunostaining in nerve fibers was slightly above background levels. Few neuroendocrine cells contained PC2 immunoreactivity, which were located predominantly in the anal transitional zone. In the squamous epithelium, the basal cell layer stained for PC2. The tissue-specific distribution of PC1/PC3 and PC2 indicates region-specific processing of peptides with regulatory functions in the anal canal and further supports the hypothesis that neuropeptides are important regulators of anal functions.

Intrinsic responses to Borna disease virus infection of the central nervous system

Immune cells invading the central nervous system (CNS) in response to Borna disease virus (BDV) antigens are central to the pathogenesis of Borna disease (BD). We speculate that the response of the resident cells of the brain to infection may be involved in the sensitization and recruitment of these inflammatory cells. To separate the responses of resident cells from those of cells infiltrating from the periphery, we used dexamethasone to inhibit inflammatory reactions in BD. Treatment with dexamethasone prevented the development of clinical signs of BD, and the brains of treated animals showed no neuropathological lesions and a virtual absence of markers of inflammation, cell infiltration, or activation normally seen in the CNS of BDV-infected rats. In contrast, treatment with dexamethasone exacerbated the expression of BDV RNA, which was paralleled by a similarly elevated expression of mRNAs for egr-1, c-fos, and c-jun. Furthermore, dexamethasone failed to inhibit the increase in expression of mRNAs for tumor necrosis factor alpha, macrophage inflammatory protein 1 beta, interleukin 6, and mob-1, which occurs in the CNS of animals infected with BDV. Our findings suggest that these genes, encoding transcription factors, chemokines, and proinflammatory cytokines, might be directly activated in CNS resident cells by BDV. This result supports the hypothesis that the initial phase of the inflammatory response to BDV infection in the brain may be dependent upon virus-induced activation of CNS resident cells.

Visualization of the vesicular acetylcholine transporter in cholinergic nerve terminals and its targeting to a specific population of small synaptic vesicles

Immunohistochemical visualization of the rat vesicular acetylcholine transporter (VAChT) in cholinergic neurons and nerve terminals has been compared to that for choline acetyltransferase (ChAT), heretofore the most specific marker for cholinergic neurons. VAChT-positive cell bodies were visualized in cerebral cortex, basal forebrain, medial habenula, striatum, brain stem, and spinal cord by using a polyclonal anti-VAChT antiserum. VAChT-immuno-reactive fibers and terminals were also visualized in these regions and in hippocampus, at neuromuscular junctions within skeletal muscle, and in sympathetic and parasympathetic autonomic ganglia and target tissues. Cholinergic nerve terminals contain more VAChT than ChAT immunoreactivity after routine fixation, consistent with a concentration of VAChT within terminal neuronal arborizations in which secretory vesicles are clustered. These include VAChT-positive terminals of the median eminence or the hypothalamus, not observed with ChAT antiserum after routine fixation. Subcellular localization of VAChT in specific organelles in neuronal cells was examined by immunoelectron microscopy in a rat neuronal cell line (PC 12-c4) expressing VAChT as well as the endocrine and neuronal forms of the vesicular monoamine transporters (VMAT1 and VMAT2). VAChT is targeted to small synaptic vesicles, while VMAT1 is found mainly but not exclusively on large dense-core vesicles. VMAT2 is found on large dense-core vesicles but not on the small synaptic vesicles that contain VAChT in PC12-c4 cells, despite the presence of VMAT2 immunoreactivity in central and peripheral nerve terminals known to contain monoamines in small synaptic vesicles. Thus, VAChT and VMAT2 may be specific markers for "cholinergic" and "adrenergic" small synaptic vesicles, with the latter not expressed in nonstimulated neuronally differentiated PC12-c4 cells.

Follicular dendritic cells, interdigitating cells, and cells of the monocyte-macrophage lineage are the C1q-producing sources in the spleen. Identification of specific cell types by in situ hybridization and immunohistochemical analysis

In a mouse model, we have shown previously that macrophages are the principal source of complement C1q. Furthermore, spleen, heart, and brain were found to contain substantial levels of murine C1q-specific mRNA, whereas liver, kidney, lung, and small intestine contained only trace amounts of C1q-specific mRNA. This work addresses the identification of C1q-expressing spleen cells in the rat, using Northern blotting and in situ detection of rat C1q mRNA combined with immunohistochemical analysis. The complete sequence of mRNA encoding the B chain of rat C1q was established. The cloned cDNA was found to hybridize primarily with spleen-derived mRNA of 1.2 kb, and additionally with a novel mRNA species of 3 kb. In situ hybridization together with immunohistochemistry revealed most of the C1q-expressing cells to be located in the red pulp of the spleen, and to be mainly of the monocyte-macrophage lineage, as indicated by coexpression of ED-1, an established marker for this type of cell. In addition, C1q was expressed in S-100-positive but ED-1-negative cells, in germinal center follicular dendritic cells, and in some interdigitating dendritic cells of the periarteriolar lymphatic sheath (PALS). These results indicate that the spleen, containing the above APCs that are all involved to a major extent in the adaptive immune response and are all capable of synthesizing C1q that is involved intimately in the innate immune response, may provide the site at which the innate and adaptive immune systems merge.

Follicular dendritic cells, interdigitating cells, and cells of the monocyte-macrophage lineage are the C1q-producing sources in the spleen. Identification of specific cell types by in situ hybridization and immunohistochemical analysis

In a mouse model, we have shown previously that macrophages are the principal source of complement C1q. Furthermore, spleen, heart, and brain were found to contain substantial levels of murine C1q-specific mRNA, whereas liver, kidney, lung, and small intestine contained only trace amounts of C1q-specific mRNA. This work addresses the identification of C1q-expressing spleen cells in the rat, using Northern blotting and in situ detection of rat C1q mRNA combined with immunohistochemical analysis. The complete sequence of mRNA encoding the B chain of rat C1q was established. The cloned cDNA was found to hybridize primarily with spleen-derived mRNA of 1.2 kb, and additionally with a novel mRNA species of 3 kb. In situ hybridization together with immunohistochemistry revealed most of the C1q-expressing cells to be located in the red pulp of the spleen, and to be mainly of the monocyte-macrophage lineage, as indicated by coexpression of ED-1, an established marker for this type of cell. In addition, C1q was expressed in S-100-positive but ED-1-negative cells, in germinal center follicular dendritic cells, and in some interdigitating dendritic cells of the periarteriolar lymphatic sheath (PALS). These results indicate that the spleen, containing the above APCs that are all involved to a major extent in the adaptive immune response and are all capable of synthesizing C1q that is involved intimately in the innate immune response, may provide the site at which the innate and adaptive immune systems merge.

Calcitonin gene related peptide gene expression in collagen-induced arthritis

Changes in calcitonin gene related peptide (CGRP) gene expression in spinal motoneurons and dorsal root ganglia (DRG) of rats subjected to collagen II induced arthritis (CIA) were evaluated by semiquantitative in situ hybridization. The effects of systemic treatment with the corticosteroid budesonide on basal CGRP expression and on changes under inflammatory conditions were examined. CIA caused a significant increase in CGRP mRNA levels in DRG. Budesonide reduced the constitutive CGRP mRNA levels in DRG, compared with untreated control rats, and reversed the CIA-induced increase. In contrast, CIA caused a marked decrease of CGRP mRNA levels in motoneurons. Budesonide had no effect on constitutive CGRP mRNA levels in motoneurons and attenuated the decrease in CGRP mRNA levels in motoneurons of rats subjected to CIA. Thus, peripheral inflammation and systemic corticosteroids have differential effects on CGRP expression in sensory and motor neurons. This may be relevant for the pathophysiology and pharmacotherapy of chronic inflammatory pain and motor dysfunction in chronic arthritis.

Expression of C1q, a subcomponent of the rat complement system, is dramatically enhanced in brains of rats with either Borna disease or experimental allergic encephalomyelitis

In situ hybridization, RT-PCR and Northern blot analysis as well immunohistochemistry were used to examine the expression of C1q, a subcomponent of the rat complement system, in brains of rats infected with Borna disease virus (BDV) and rats afflicted with experimental allergic encephalomyelitis (EAE) induced by the adoptive transfer of myelin basic protein specific T cells. C1q mRNA, which was not detected in normal brain, became clearly detectable using RT-PCR analysis by d14 post infection (p.i.) with BDV. Maximal levels of C1q mRNA were reached 21 days p.i. when inflammatory reactions in the brain were also at a peak. Similarly, C1q mRNA was elevated when the clinical symptoms of EAE became evident 5 days following cell transfer. C1q positive cells, as identified by immunohistology, were preferentially localized in grey and white matter of the hippocampus and basolateral cortex. The C1q positive cells resembled microglial cells in morphology. The correlation of C1q expression with the development of neurological disease as well as the dramatic increase of C1q within brain regions with inflammatory lesions suggest that local biosynthesis of C1q may play a role in the pathogenesis of Borna virus induced and autoimmune encephalomyelitis.

The distinct gene expression of the pro-hormone convertases in the rat heart suggests potential substrates

The present study examined the distribution of the pro-hormone convertases PC1, PC2, furin, PACE4 and PC5 in the rat heart. Northern blot analysis of RNA extracted from cardiac tissues showed high levels of furin and PACE4 mRNA in the atria and ventricles, while PC5 mRNA was found to be expressed at high levels in the dorsal aorta. Although undetectable by Northern blot analysis, both PC1 and PC2 mRNA were detected by in situ hybridization and immunohistochemistry in discrete regions of the intracardiac para-aortic ganglia. In situ hybridization studies also showed that furin mRNA was observed in all cardiac tissues and cells, consistent with the previously reported ubiquitous expression of this gene. PACE4 mRNA was highly abundant in both the atria and ventricular cardiomyocytes, with low to undetectable levels observed in blood vessels. Finally, PC5 transcripts were expressed in the endothelial cells lining coronary vessels and the valve leaflets of the heart. The present localization studies in the heart and cardiac blood vessels suggests potential roles for each convertase in the processing of various neuropeptides, hormones and growth factors.

Opioid peptides in the pituitary: a hormone, a paracrine modulator and a peptide in search of a function

Endogenous opioid peptides derived from all three opioid precursors have been isolated from the pituitary of mammalian species. While beta-endorphin of the anterior lobe was soon shown to be secreted into the circulation as a hormone, the dynorphins and the enkephalins were found to occur in relative small quantities too low for export and effects in the periphery. With respect to the prodynorphin family in the neural lobe convincing evidence has been accumulated for a role of dynorphin A(1-8) in the local control of the release of the hormone oxytocin. The function of the enkephalins in the anterior and neural lobes, in spite of many efforts with in situ hybridization, immunocytochemistry, receptor autoradiography and receptor binding and bioassays, is still elusive. Research should be directed into the role of enkephalins in different physiological states, developmental stages and in non-mammalian vertebrate species.

Spinal prodynorphin gene expression in collagen-induced arthritis: influence of the glucocorticosteroid budesonide

Changes in the spinal expression of the opioid precursor and prodynorphin, which has been implicated in the response to peripheral inflammation, were examined with semi-quantitative in situ hybridization histochemistry in rats subjected to collagen II-induced arthritis. The effects of glucocorticosteroid treatment on the basal and inflammation-induced prodynorphin expression were evaluated. Collagen II-induced arthritis caused a 16-fold increase in prodynorphin mRNA levels which comprised all neurons expressing low levels under normal conditions. In the superficial dorsal horn, one group of neurons of a large size reacted with a dramatic increase of prodynorphin mRNA, while another group of small neurons exhibited a moderate elevation of prodynorphin mRNA levels. In the deep dorsal horn of arthritic rats, most prodynorphin neurons were large and showed high prodynorphin mRNA levels. Systemic treatment with the glucocorticosteroid budesonide attenuated the arthritis-induced increase of prodynorphin mRNA expression in a topospecific manner. The budesonide-induced reduction of prodynorphin mRNA levels was more pronounced in the deep dorsal horn than in the superficial dorsal horn. Budesonide treatment of control animals caused a small, but significant increase in prodynorphin mRNA levels in the superficial laminae I/II without affecting prodynorphin mRNA levels in the deep dorsal horn. The degree of arthritis correlated closely with spinal prodynorphin mRNA levels. The tight correlation between severity of arthritis and prodynorphin mRNA levels in non-treated and corticosteroid-treated arthritic rats suggests that spinal prodynorphin expression is a good parameter for the evaluation of the influence of peripheral inflammation and of the efficacy of analgesic/anti-inflammatory drugs in its treatment. Opposite effects of budesonide on basal and inflammation-induced prodynorphin expression may involve a spinal site of action in addition to peripheral anti-inflammatory mechanisms. We suggest that the collagen II-induced arthritis in the rat is an excellent model for human rheumatoid arthritis allowing for the study of molecular plasticity of anti-inflammatory and anti-nociceptive drug action at different levels of the neuroaxis.

Differential expression of mRNA encoding interleukin-12 p35 and p40 subunits in situ

Interleukin-12 (IL-12) is a heterodimeric cytokine that plays an important role in the regulation of the immune response. For biological activity the expression of both subunits of IL-12, p35 and p40, is required. Moreover, in the mouse the p40 chain of IL-12 specifically inhibits the effects of the IL-12 heterodimer. In the present study we have analyzed by in situ hybridization the expression of the p35 and p40 mRNA in the spleens of BALB/c and mutant (SCID, nude, beige) mice, unstimulated and after in vivo stimulation with lipopolysaccharide (LPS) and with staphylococcal enterotoxin B (SEB). In unstimulated spleens of BALB/c mice p35 and p40 mRNA were only detectable in a few strongly stained single cells, p35 mRNA was expressed in addition weakly in the B cell areas. After injection of LPS or SEB, p40 mRNA was strongly induced in the T cell areas all over the spleen, whereas expression of p35 mRNA and its distribution pattern did not change. Surprisingly, most of the mRNA for p35 and p40 was localized in different areas of the spleen and was apparently produced by different cells. In macrophage-depleted spleens the increased expression of p40 mRNA in response to LPS was reduced but still detectable, demonstrating that other cells besides macrophages can up-regulate IL-12 p40 mRNA. Nude mice showed a stronger expression of p35 mRNA, SCID mice lacked the weak p35 staining of the B cell areas but showed a strong basal expression of both p35 and p40 mRNA and a focal response to LPS. The pattern of IL-12 mRNA expression in beige mice was the same as in normal mice. These data demonstrate a spatial dissociation of expression of the two chains of IL-12 and are compatible with a regulatory role of the isolated IL-12 p40 chain in vivo. In addition, they indicate that the demonstration of mRNA for both chains of IL-12 in whole tissues or cell mixtures is not necessarily indicative of functional IL-12.

Functional identification of a vesicular acetylcholine transporter and its expression from a "cholinergic" gene locus

The vesicular acetylcholine transporter (VAChT) has been identified and characterized based on the acquisition of high affinity vesamicol binding and proton-dependent, vesamicol-sensitive acetylcholine accumulation by a fibroblast cell line transfected with a clone from a rat pheochromocytoma cDNA library encoding this protein. The distribution of VAChT mRNA coincides with that reported for choline acetyltransferase (ChAT), the enzyme required for acetylcholine biosynthesis, in the peripheral and central cholinergic nervous systems. A human VAChT cDNA was used to localize the VAChT gene to chromosome 10q11.2, which is also the location of the ChAT gene. The entire sequence of the human VAChT cDNA is contained uninterrupted within the first intron of the ChAT gene locus. Transcription of VAChT and ChAT mRNA from the same or contiguous promoters within a single regulatory locus provides a previously undescribed genetic mechanism for coordinate regulation of two proteins whose expression is required to establish a mammalian neuronal phenotype.

Localization of vesicular monoamine transporter isoforms (VMAT1 and VMAT2) to endocrine cells and neurons in rat

Polyclonal antipeptide antibodies have been raised against each of the two isoforms of the rat vesicular monoamine transporter, VMAT1 and VMAT2. Antibody specificity was determined by isoform-specific staining of monkey fibroblasts programmed to express either VMAT1 or VMAT2. The expression of VMAT1 and VMAT2 in the diffuse neuroendocrine system of the rat has been examined using these polyclonal antibodies specific for either VMAT1 or VMAT2. VMAT1 is expressed exclusively in endocrine/paracrine cells associated with the intestine, stomach, and sympathetic nervous system. VMAT2 is expressed in neurons of the sympathetic nervous system, and aminergic neurons in the enteric and central nervous systems. VMAT2 is expressed in at least two endocrine cell populations in addition to its expression in neurons. A subpopulation of chromogranin A (CGA)-expressing chromaffin cells of the adrenal medulla also express VMAT2, and the oxyntic mucosa of the stomach contains a prominent population of CGA- and VMAT2-positive endocrine cells. The expression of VMAT2 in neurons, and the mutually exclusive expression of VMAT1 and VMAT2 in endocrine/paracrine cell populations of stomach, intestine, and sympathetic nervous system may provide a marker for, and insight into, the ontogeny and monoamine-secreting capabilities of multiple neuroendocrine sublineages in the diffuse neuroendocrine system.

Distribution of the vesicular acetylcholine transporter (VAChT) in the central and peripheral nervous systems of the rat

Expression of the acetylcholine biosynthetic enzyme choline acetyltransferase (ChAT), the vesicular acetylcholine transporter (VAChT), and the high-affinity plasma membrane choline transporter uniquely defines the cholinergic phenotype in the mammalian central (CNS) and peripheral (PNS) nervous systems. The distribution of cells expressing the messenger RNA encoding the recently cloned VAChT in the rat CNS and PNS is described here. The pattern of expression of VAChT mRNA is consistent with anatomical, pharmacological, and histochemical information on the distribution of functional cholinergic neurons in the brain and peripheral tissues of the rat. VAChT mRNA-containing cells are present in brain areas, including neocortex and hypothalamus, in which the existence of cholinergic neurons has been the subject of debate. The demonstration that VAChT is a completely adequate marker for cholinergic neurons should allow the systematic delineation of cholinergic synapses in the rat nervous system when antibodies directed to this protein are available.

Localization of kappa-opioid receptor mRNA in neuronal subpopulations of rat sensory ganglia and spinal cord

A partial cDNA encoding a kappa-opioid receptor was isolated and used to generate specific 35S-labeled probes to investigate the gene expression of the kappa-opioid receptor in sensory, sympathetic and spinal neurons of the rat by in situ hybridization. A subpopulation of mainly small and medium-sized neurons within dorsal root and trigeminal ganglia expressed kappa-receptor mRNA, but no signal was detectable in the superior cervical ganglion. kappa-Receptor mRNA was distributed over neurons throughout the dorsal horn and in laminae VII/VIII. Highest concentrations of positive neurons were seen in laminae I/II, dorsal lamina X and in the lateral spinal nucleus. alpha-Motoneurons and glial cells were not labeled. This distribution of kappa-receptor mRNA indicates preferential functions of kappa-receptors in sensory signalling with particular importance to nociception.

Pan-neuronal expression of chromogranin A in rat nervous system

Sensitive and specific in situ hybridization detection of CGA mRNA, and immunohistochemistry with an antibody recognizing the CGA(316-329) epitope within CGA and its proteolytic fragments were employed to determine whether or not CGA mRNA or protein expression are restricted to specific neuronal subpopulations within the central and peripheral nervous systems. Virtually all neurons in sympathetic, sensory, and parasympathetic ganglia examined, as well as enteric nervous system and spinal cord, expressed both CGA mRNA and the 316-329 (WE-14) CGA epitope. Chromogranin A expression was also ubiquitous within all telencephalic and diencephalic brain nuclei examined, including frontal cortex, striatum, and hippocampus. In addition, CGA mRNA was expressed in nonneuronal cells that appeared to be glia in dorsal root ganglion, spinal cord, and brain. In contrast to earlier reports, neuronal expression of CGA appears to be unrestricted within the central and peripheral nervous systems. Nonneuronal expression of CGA also occurs in the nervous system, albeit at levels much lower than in neuronal cells.

Prodynorphin gene expression in the rat intermediate pituitary lobe: gender differences and postpartum regulation

The distribution of prodynorphin (proDyn) messenger RNA (mRNA) was examined in the rat pituitary using Northern and in situ hybridization analysis. Anterior pituitary gonadotrophs are known to express ProDyn, but the present study demonstrated that proDyn mRNA was also expressed in the intermediate lobe melanotrophs and was colocalized with POMC mRNA. The 2.6-kilobase proDyn transcript observed in the intermediate lobe was shown to be translatable by polysome analysis. Immunohistochemical studies showed dynorphin (Dyn)-like immunoreactivity in all intermediate lobe melanotrophs. Intermediate lobe proDyn gene expression was not regulated by dopamine, in contrast to intermediate lobe POMC mRNA levels, which were increased with haloperidol and decreased with bromocriptine treatment, as expected. A gender difference in ProDyn gene expression was noted, since intermediate lobes of male rats had nearly 2-fold higher proDyn mRNA levels than intermediate lobes of female rats. In contrast, no gender difference of intermediate lobe POMC mRNA levels were detected. ProDyn mRNA levels were up-regulated by 3- to 4-fold in the intermediate lobes of postpartum females as compared to pregnant or nonpregnant female rats, whereas POMC mRNA levels were unchanged, suggesting a role for intermediate lobe ProDyn in the postpartum period of the female rat. Although our results demonstrate proDyn and POMC coexpression in the pituitary intermediate lobe melanotrophs and show a differential regulational control for each gene in this tissue, the present data also strengthen the notion that proDyn is a precursor that has a role to play in reproductive functions.

Differential effects of rabies and borna disease viruses on immediate-early- and late-response gene expression in brain tissues

In situ hybridization and Northern blot analysis were used to examine expression of the immediate-early-response genes (IEGs) egr-1, junB, and c-fos, and the late response gene encoding enkephalin in the brains of rats infected intranasally with Borna disease virus (BDV) or rabies virus. In both Borna disease and rabies virus infections, a dramatic and specific induction of IEGs was detected in particular regions of the hippocampus and the cortex. Increased IEG mRNA expression overlapped with the characteristic expression patterns of BDV RNA and rabies virus RNA, although relative expression levels of viral RNA and IEG mRNA differed, particularly in the hippocampal formation. Furthermore, the temporal relationship between viral RNA synthesis and activation of IEG mRNA expression in BDV infection differed markedly from that in rabies virus infection, suggesting that IEG expression is upregulated by different mechanisms. Expression of proenkephalin (pENK) mRNA was also significantly increased in BDV infection, whereas in rabies virus infection, pENK mRNA levels and also the levels of glyceraldehyde-3-phosphate dehydrogenase mRNA were reduced at terminal stages of the disease, probably reflecting a generalized suppression of cellular protein synthesis due to massive production of rabies virus mRNA. The correlation between activated IEG mRNA expression and the strong increase in viral RNA raises the possibility that IEG products induce some phenotypic changes in neurons that render them more susceptible to viral replication.

Distribution and kinetics of superantigen-induced cytokine gene expression in mouse spleen

The polyclonal stimulation of T cells by bacterial superantigens is involved in the pathogenesis of the toxic shock syndrome in certain staphylococcal and streptococcal infections. Here we describe the onset and kinetics of superantigen-induced cytokine production in situ in spleens of normal BALB/c mice monitored at the level of cytokine mRNA expression by in situ hybridization. Messenger RNAs for interleukin 2 (IL-2), interferon gamma, and tumor necrosis factors (TNF) alpha and beta were not expressed at detectable levels in spleens of unstimulated animals but became visible already 30 min after intraperitoneal application of 50 micrograms staphylococcal enterotoxin B. All mRNA levels showed peak expression approximately 3 h after injection and a slow decrease up to 24 h after injection. Expression of the mRNAs was restricted to the T cell-dependent area of the periarteriolar lymphatic sheets of the spleen. Interestingly, TNF-alpha mRNA showed a biphasic response, the early appearing mRNA had the same localization as the other mRNAs, whereas after 3 h TNF-alpha mRNA showed a broader distribution indicating a second cell population producing TNF-alpha. The expression of IL-2 and TNF proteins in the serum increased in parallel to the observed mRNA changes with a slight delay. The presence of macrophages was not required for the expression of the cytokine mRNAs in the spleen as the expression was unchanged in macrophage-depleted mice. Only the second phase of TNF-alpha mRNA expression was abrogated in such animals. The expression of all mRNAs was completely suppressed by prior administration of cyclosporin A. These data show that nonphagocytic cells are the essential superantigen-presenting cells in vivo and indicate that at least part of the pathogenetic TNF-alpha is T cell derived.

Severity of neurological signs and degree of inflammatory lesions in the brains of rats with Borna disease correlate with the induction of nitric oxide synthase

The putative role of nitric oxide in the neuropathogenesis of Borna disease was investigated by determining changes in the expression of inducible nitric oxide synthase (iNOS) mRNA and constitutively expressed NOS (cNOS) mRNA in brains of Borna disease virus (BDV)-infected rats. iNOS mRNA was not detected in normal rat brain but was identified in BDV-infected brain at 14 days postinfection (p.i.), reaching maximum levels at 21 days p.i., when neurological signs and inflammatory reactions in the brain were also at a peak. cNOS mRNA was expressed in both normal brain and infected brain, increasing markedly at 17 days p.i. and reaching a peak at 21 days p.i. In situ hybridization analysis revealed iNOS mRNA in some, but not all, BDV-infected regions of the brain, particularly in the basolateral cortex and the hippocampus. iNOS-positive cells, as identified immunohistologically, were preferentially localized in perivascular areas of the hippocampus and in outer cortical layers. These iNOS-positive cells resembled monocytes/macrophages in morphology and distribution pattern but were significantly fewer. The correlation of iNOS and cNOS mRNA expression with the development of neurological disease, as well as the enhanced expression of iNOS within brain regions with inflammatory lesions, strongly suggests that NO may contribute to pathogenesis of Borna disease.