Clinical Neuroscience

[SALSOLINOL AND THE PERIPHERAL SYMPATHETIC ACTIVITY: THE EFFECTS OF HYPOPHYSECTOMY, ADRENALECTOMY AND ADRENAL MEDULLECTOMY]

SZÉKÁCS Dániel1, BODNÁR Ibolya1, NAGY M. György1, FEKETE I.K. Márton1

MARCH 20, 2007

Clinical Neuroscience - 2007;60(03-04)

[The endogenous isoquinoline salsolinol (SALS) is a recently identified prolactin (PRL) releasing factor, a selective and potent stimulator of PRL secretion both in vivo and in vitro. SALS decreased the peripheral tissue dopamine (DA) level dose dependently, consequently increased the NE/DA ratio, indicating reduced release of newly formed norepinephrine (NE) from sympathetic terminals. The aim of our study was to investigate the effect of adrenal medullectomy (MEDX), adrenalectomy (ADX) and hypophysectomy (HYPOX) on the action of SALS on the PRL secretion, and on the catecholamine concentration of the selected sympathetically innervated peripheral tissues (atrium, spleen, etc). The experiments were done in male rats of 200-300 g body weight kept in air conditioned room with regular lighting. We used high-pressure liquid chromatography with electrochemical detection (HPLC-EC) for measurement of NE and DA concentrations, and radioimmunoassay for prolactin measurement. In MEDX as well as in ADX rats, SALS (25 mg/kg i.p.) was able to reduce DA level and increase the NE/DA ratio. The changes of prolactin secretion (increase by SALS) were not affected either by ADX or MEDX. Therefore the presence of the adrenal gland is not required for the changes of prolactin secretion, nor for the reduction of peripheral sympathetic activity induced by SALS. Investigating the possible effect of pituitary hormones on the peripheral sympathetic system, the action of SALS has been tested in HYPOX rats. We have found that the effect of SALS on peripheral sympathetic terminals is not affected by HYPOX, consequently the role of pituitary hormones in the effect of SALS on the peripheral catecholamine metabolism may be excluded.]

AFFILIATIONS

  1. Neuromorphological and Neuroendocrine Research Laboratory, Department of Human Morphology, Hungarian Academy of Sciences and Semmelweis University, Budapest

COMMENTS

0 comments

Further articles in this publication

Clinical Neuroscience

[BRAIN INSULIN SIGNALLING IN THE REGULATION OF ENERGY BALANCE AND PERIPHERAL METABOLISM]

MICHAELA Diamant

[The unparalleled global rates of obesity and type 2 diabetes, together with the associated cardiovascular morbidity and mortality, are referred to as the "diabesity pandemic". Changes in lifestyle occurring worldwide, including the increased consumption of high-caloric foods and reduced exercise, are regarded as the main causal factors. Central obesity and insulin resistance have emerged as important linking components. Understanding the aetiology of the cluster of pathologies that leads to the increased risk is instrumental in the development of preventive and therapeutic strategies. Historically, skeletal muscle, adipose tissue and liver were regarded as key insulin target organs involved in insulinmediated regulation of peripheral carbohydrate, lipid and protein metabolism. The consequences of impaired insulin action in these organs were deemed to explain the functional and structural abnormalities associated with insulin resistance. The discovery of insulin receptors in the central nervous system, the detection of insulin in the cerebrospinal fluid after peripheral insulin administration and the well-documented effects of intracerebroventricularly injected insulin on energy homeostasis, have identified the brain as an important target for insulin action. In addition to its critical role as a peripheral signal integrating the complex network of hypothalamic neuropeptides and neurotransmitters that influence parameters of energy balance, central nervous insulin signalling is also implicated in the regulation of peripheral glucose metabolism. This review summarizes the evidence of insulin action in the brain as part of the multifaceted circuit involved in the central regulation of energy and glucose homeostasis, and discuss the role of impaired central nervous insulin signalling as a pathogenic factor in the obesity and type 2 diabetes epidemic.]

Clinical Neuroscience

[PROTECTIVE ACTION OF SNAKE VENOM NAJA NAJA OXIANA AT SPINAL CORD HEMISECTION]

ABRAHAMYAN S. Silva, MELIKSETYAN B. Irina, CHAVUSHYAN A. Vergine, ALOYAN L. Mery, SARKISSIAN S. John

[Based on data accumulated regarding the neuroprotective action of Proline-Rich-Peptide-1 (PRP-1, a fragment of neurophysin vasopressin associated hypothalamic glycoprotein consisting of 15 amino acid residues) on neurons survival and axons regeneration and taking into the account that LVV-Hemorphin-7 (LVV-H7, an opioid peptide, widely distributed in different cell types of various tissues of intact rats, including those of the nervous and immune systems) derived from the proteolitic processing of hemoglobin in response to adverse environmental and physiological conditions, possesses the anti-stressor properties, we used histochemistry, immunohistochemistry and electrophysiology to investigate the putative neuroprotective action of Central Asian Cobra Naja naja oxiana snake venom (NOX) on trauma-injured rats. ABC immunohistochemical method and histochemical method on detection of Ca2+- dependent acid phosphatase activity were used for the morpho-functional study. By recording the electrical activity of the signals from the single neurons in and below the SC injury place, NOX venom has been shown to result in the complete restoration of hypothalamic-spinal projections originated from ipsi- and contra-lateral PVN and SON to neurons of SC lumbar part. NOX prevented the scar formation, well observed two months after SC injury in the control rats, resulted in the regeneration of nerve fibers growing through the trauma region, survival of the PRP-1- and LVV-H7-immunoreactive (Ir) neurons, and increase of the PRP-1- and LVV-H7-Ir nerve fibers and astrocytes in the SC lesion region. NOX was suggested to exert the neuroprotective effect, involving the PRP-1 and LVV-H7 in the underlying mechanism of neuronal recovery.]

Clinical Neuroscience

[HISTOCHEMISTRY OF THE EXTRACELLULAR MATRIX IN THE SNAIL CENTRAL NERVOUS SYSTEM]

SERFŐZŐ Zoltán, ELEKES Károly

[Even tough the central nervous system (CNS) of gastropods has long been used as a model for studying different neuronal networks underlying behaviors, there is only little information on the molecular components of the extracellular matrix (ECM) of the nervous tissue. Therefore, the aim of the present study was to identify some of the ECM molecules by acid-base histochemistry. Staining with alcian blue at strong acidic pH, and with acridine orange at different pH and salt concentrations was carried out on cryostat sections taken from CNS preparations of adult specimens of the terrestrial snail, Helix pomatia, and the aquatic species, Lymnaea stagnalis, in order to visualize mild (carboxyl) and strong (sulphate) acidic groups, which are characteristic for different glucosaminoglycans. According to our findings, sulphated proteoglycans were abundant in the periganglionic sheath of both species, and they also occurred in the neuropil of Helix, whereas they were absent in Lymnaea. The interperikaryonal space contained mainly carboxyl residues, which might refer to the presence of hyaluronic acid. It is concluded that the ECM of the snail CNS, similarly to that in vertebrates, is partly composed of polymer macromolecules of different chemical properties. It is suggested that adaptation to environmental conditions and/or altered neuronal plasticity are responsible for the differences found in chemical characters of the ECM molecules between the two snail species.]

Clinical Neuroscience

[In memoriam Mariann Fodor]

Clinical Neuroscience

[PROJECTIONS OF VIP/PHI NEURONS OF THE INTERSTITIAL NUCLEUS OF CAJAL IN THE RAT]

FODOR Mariann, WILLIAM Rostène, ANNE Berod, BENCZE Viktória, PALKOVITS Miklós

[Neurons expressing VIP/PHI precursor mRNA have been localized in the interstitial nucleus of Cajal. Unilateral surgical cut through the medial forebrain bundle failed to influence VIP/PHI mRNA expression in the Cajal nucleus while brainstem hemisection or unilateral transection of the medial longitudinal fascicle reduced it markedly, ipsilateral to the knife cuts. Thus, in contrast to forebrain projecting VIP neurons in the rostral periaqueductal gray, VIP/PHI neurons in the Cajal nucleus project downwards, to the lower brainstem.]

All articles in the issue

Related contents

Clinical Neuroscience

[EFFECT OF LOCAL (INTRACEREBRAL AND INTRACEREBROVENTRICULAR) ADMINISTRATION OF TYROSINE HYDROXYLASE INHIBITOR ON THE NEUROENDOCRINE DOPAMINERGIC NEURONS AND PROLACTIN RELEASE]

BODNÁR Ibolya, HECHTL Dániel, SZÉKÁCS Dániel, OLÁH Márk, NAGY M. György

[Background and purpose - Hypothalamic dopamine (DA), the physiological regulator of pituitary prolactin (PRL) secretion, is synthesized in the neuroendocrine DAergic neurons that projects to the median eminence and the neurointermediate lobe of the pituitary gland. The rate-limiting step of DA biosynthesis is catalyzed by the phosphorylated, therefore activated, tyrosine hydroxylase (TH) that produces L-3,4-dihydroxy- phenylalanine from tyrosine. The aims of our present study were to investigate 1. the effect of local inhibition of the DA biosynthesis in the hypothalamic arcuate nucleus on PRL release, and to get 2. some information whether the phosphorylated TH is the target of enzyme inhibition or not. Methods - A TH inhibitor, α-methyl-p-tyrosine was injected either intracerebro-ventricularly or into the arcuate nucleus of freely moving rats and plasma PRL concentration was measured. Immunohistochemistry, using antibodies raised against to native as well as phosphorylated TH were used to compare their distributions in the arcuate nucleus-median eminence region. Results - Intracerebro-ventricular administration of α-methyl-p-tyrosine has no effect, unlike the intra-arcuatus injection of enzyme inhibitor resulted in a slight but significant elevation in plasma PRL. Parallel with this, the level of DA and DOPAC were reduced in the neurointermediate lobe while no change in norepinephrine concentration can be detected indicating a reduced biosynthesis of dopamine following TH inhibition. On the other hand, systematic application of the α-methyl-p-tyrosine that inhibits TH activity located in DA terminals of the median eminence and the neurointermediate lobe, resulted in the most significant elevation of PRL. Conclusion - Our results suggest that α-methyl-p-tyrosine administered close to the neuroendocrine DAergic neurons was able to inhibit only a small proportion of the TH. Moreover, it also indicate that the majority of the activated TH can be found in the axon terminals of DAergic neurons, therefore, the DA released into the pituitary portal circulation is synthesized at this site.]

Clinical Neuroscience

Late simultaneous carcinomatous meningitis, temporal bone infiltrating macro-metastasis and disseminated multi-organ micro-metastases presenting with mono-symptomatic vertigo – a clinico-pathological case reporT

JARABIN András János, KLIVÉNYI Péter, TISZLAVICZ László, MOLNÁR Anna Fiona, GION Katalin, FÖLDESI Imre, KISS Geza Jozsef, ROVÓ László, BELLA Zsolt

Although vertigo is one of the most common complaints, intracranial malignant tumors rarely cause sudden asymmetry between the tone of the vestibular peripheries masquerading as a peripheral-like disorder. Here we report a case of simultaneous temporal bone infiltrating macro-metastasis and disseminated multi-organ micro-metastases presenting as acute unilateral vestibular syndrome, due to the reawakening of a primary gastric signet ring cell carcinoma. Purpose – Our objective was to identify those pathophysiological steps that may explain the complex process of tumor reawakening, dissemination. The possible causes of vestibular asymmetry were also traced. A 56-year-old male patient’s interdisciplinary medical data had been retrospectively analyzed. Original clinical and pathological results have been collected and thoroughly reevaluated, then new histological staining and immunohistochemistry methods have been added to the diagnostic pool. During the autopsy the cerebrum and cerebellum was edematous. The apex of the left petrous bone was infiltrated and destructed by a tumor mass of 2x2 cm in size. Histological reexamination of the original gastric resection specimen slides revealed focal submucosal tumorous infiltration with a vascular invasion. By immunohistochemistry mainly single infiltrating tumor cells were observed with Cytokeratin 7 and Vimentin positivity and partial loss of E-cadherin staining. The subsequent histological examination of necropsy tissue specimens confirmed the disseminated, multi-organ microscopic tumorous invasion. Discussion – It has been recently reported that the expression of Vimentin and the loss of E-cadherin is significantly associated with advanced stage, lymph node metastasis, vascular and neural invasion and undifferentiated type with p<0.05 significance. As our patient was middle aged and had no immune-deficiency, the promoting factor of the reawakening of the primary GC malignant disease after a 9-year-long period of dormancy remained undiscovered. The organ-specific tropism explained by the “seed and soil” theory was unexpected, due to rare occurrence of gastric cancer to metastasize in the meninges given that only a minority of these cells would be capable of crossing the blood brain barrier. Patients with past malignancies and new onset of neurological symptoms should alert the physician to central nervous system involvement, and the appropriate, targeted diagnostic and therapeutic work-up should be established immediately. Targeted staining with specific antibodies is recommended. Recent studies on cell lines indicate that metformin strongly inhibits epithelial-mesenchymal transition of gastric cancer cells. Therefore, further studies need to be performed on cases positive for epithelial-mesenchymal transition.

Hypertension and nephrology

[About the care of patients with hyperuricaemia and gout]

[This consensus document is intended to provide guidance for the effective and efficient treatment of asymptomatic individuals with high uric acid levels and gout patients.]

Clinical Neuroscience

[What happens to vertiginous population after emission from the Emergency Department?]

MAIHOUB Stefani, MOLNÁR András, CSIKÓS András, KANIZSAI Péter, TAMÁS László, SZIRMAI Ágnes

[Background – Dizziness is one of the most frequent complaints when a patient is searching for medical care and resolution. This can be a problematic presentation in the emergency department, both from a diagnostic and a management standpoint. Purpose – The aim of our study is to clarify what happens to patients after leaving the emergency department. Methods – 879 patients were examined at the Semmel­weis University Emergency Department with vertigo and dizziness. We sent a questionnaire to these patients and we had 308 completed papers back (110 male, 198 female patients, mean age 61.8 ± 12.31 SD), which we further analyzed. Results – Based on the emergency department diagnosis we had the following results: central vestibular lesion (n = 71), dizziness or giddiness (n = 64) and BPPV (n = 51) were among the most frequent diagnosis. Clarification of the final post-examination diagnosis took several days (28.8%), and weeks (24.2%). It was also noticed that 24.02% of this population never received a proper diagnosis. Among the population only 80 patients (25.8%) got proper diagnosis of their complaints, which was supported by qualitative statistical analysis (Cohen Kappa test) result (κ = 0.560). Discussion – The correlation between our emergency department diagnosis and final diagnosis given to patients is low, a phenomenon that is also observable in other countries. Therefore, patient follow-up is an important issue, including the importance of neurotology and possibly neurological examination. Conclusion – Emergency diagnosis of vertigo is a great challenge, but despite of difficulties the targeted and quick case history and exact examination can evaluate the central or peripheral cause of the balance disorder. Therefore, to prevent declination of the quality of life the importance of further investigation is high.]