1
|
Hrivikova K, Zelena D, Graban J, Puhova A, Miklya I, Balazsfi D, Jezova D. Chronic treatment with enhancer drugs modifies the gene expression of selected parameters related to brain plasticity in rats under stress conditions. Neurochem Int 2022; 159:105404. [PMID: 35853552 DOI: 10.1016/j.neuint.2022.105404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 11/17/2022]
Abstract
Selegiline, also known as L-deprenyl, and (2R)-1-(1-benzofuran-2-yl)-N-propylpentane-2-amine (BPAP) were found to induce enhancement of monoamine neurotransmission in low and very low doses. In addition, these enhancers may modify glutamatergic neurotransmission. The aim of the present study was to test the hypothesis that under stress conditions, chronic treatment with enhancer drugs has a positive impact on the glutamatergic system and other parameters related to brain plasticity, stress-related systems, and anxiety behavior. We exposed male Wistar rats to a chronic mild stress procedure combined with chronic treatment with two synthetic enhancer drugs. The gene expression of GluR1, an AMPA receptor subunit was reduced by repeated treatment with deprenyl in the hippocampus and with both BPAP and deprenyl in the prefrontal cortex. A significant reduction of NMDA receptor subunit GluN2B expression was observed in the hippocampus but not in the prefrontal cortex. Deprenyl treatment led to an enhancement of hippocampal BDNFmRNA concentrations in stress-exposed rats. Treatment with enhancer drugs failed to induce significant changes in stress hormone concentrations or anxiety behavior. In conclusion, the present study in chronically stressed rats showed that concomitant treatment with enhancer drugs did not provoke substantial neuroendocrine changes, but modified gene expression of selected parameters associated with brain plasticity. Observed changes may indicate a positive influence of enhancer drugs on brain plasticity, which is important for preventing negative consequences of chronic stress and enhancement of stress resilience. It may be suggested that the changes in glutamate receptor subunits induced by enhancer drugs are brain region-specific and not dose-related.
Collapse
Affiliation(s)
- K Hrivikova
- Laboratory of Pharmacological Neuroendocrinology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - D Zelena
- Institute of Physiology, Medical School, University of Pécs, Centre for Neuroscience, Szentágothai Research Centre, 7624, Pécs, Hungary; Department of Behavioral Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - J Graban
- Laboratory of Pharmacological Neuroendocrinology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - A Puhova
- Laboratory of Pharmacological Neuroendocrinology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - I Miklya
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, 1089, Budapest, Nagyvarad Ter 4, Hungary
| | - D Balazsfi
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Szigony 43, Hungary
| | - D Jezova
- Laboratory of Pharmacological Neuroendocrinology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia.
| |
Collapse
|
2
|
Zelena D. Comparison of natural and artificial vasopressin deficiency: why the latter is lethal? Vavilovskii Zhurnal Genet Selektsii 2016. [DOI: 10.18699/vj16.142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
3
|
Fodor A, Klausz B, Toth B, Zelena D. The prepulse inhibition deficit appearance is largely independent on the circadian cycle, body weight, and the gender of vasopressin deficient Brattleboro rat. Endocr Regul 2016; 50:16-23. [DOI: 10.1515/enr-2016-0004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Objective. A disturbance of sensorimotor gating measured by prepulse inhibition of acoustic startle (PPI) is one of the best tests of the schizophrenia-like behavior. Vasopressin was implicated in the development of schizophrenia; therefore, the naturally occurring vasopressin-deficient Brattleboro rat has been suggested to be a reliable non-pharmacological animal model. However, previous studies focusing on PPI deficit did not use proper control and despite clear gender differences in the development of the disorder, the effect of gender has been mostly neglected.
Methods. First, we compared the „noise” and „tone” type prepulse at 73-77-81 dB intensity during the light or dark phase using small (~150 g) or big (~500 g) Wistar rats. The test parameters were validated by a pharmacological schizophrenia model (30 mg/kg ketamine i.p.). Than male, female, and lactating vasopressin-deficient animals were compared with +/+ ones.
Results. We established that the prepulse “noise” type is not optimal for PPI testing. The cycle of the day as well as the body weight had no effect on PPI. Even if we compared vasopressin-deficient animals with their closely related +/+ controls, the PPI deficiency was visible with more pronounced effect at 77 dB prepulse intensity similarly to pharmacological schizophrenia model. Despite our expectation, the gender as well as lactation had no effect on the vasopressin-deficiency induced PPI deficit.
Conclusions. The present data confirmed and extended our previous studies that vasopressin-deficient rat is a good model of schizophrenia. It seems that female as well as lactating Brattleboro rats are useful tools for testing putative novel antipsychotics in line with special attention required for schizophrenic women.
Collapse
Affiliation(s)
- A Fodor
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- Janos Szentagothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - B Klausz
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - B Toth
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - D Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| |
Collapse
|
4
|
Filaretova LP, Bagaeva TR, Morozova OY, Zelena D. A wider view on gastric erosion: detailed evaluation of complex somatic and behavioral changes in rats treated with indomethacin at gastric ulcerogenic dose. Endocr Regul 2015; 48:163-72. [PMID: 25512189 DOI: 10.4149/endo_2014_04_163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Gastric erosion is widespread side effect of nonsteroidal anti-inflammatory drugs. To examine the complexity of the brain-gut axis regulation, indomethacin-induced gastric erosion formation was studied in connection with somatic and behavioral changes. METHODS During a constant telemetric recording of heart rate, body temperature, and locomotion of male rats we examined the effects of 24 h fasting, indomethacin (35 mg/kg s.c.) injection, and refeeding at 4 h. Behavior was analyzed on elevated plus maze (EPM) at 24 h and somatic changes at 72 h. RESULTS Gastric erosion developed 4 h after indomethacin injection, healed 72 h later contrasted by large injury in the small intestine. As classical signs of chronic stress, body and thymus weight were reduced while adrenal weight was enhanced 72 h after indomethacin injection. Fasting by itself changed all telemetrically recorded parameters with most prominent decrease in heart rate. Indomethacin induced similar diminishing effects with earliest and strongest temperature decrease. As a sign of more anxious phenotype locomotion reducing effect of indomethacin injection was detected on EPM. The EPM-induced temperature elevation was missing in indomethacin-treated animals. CONCLUSIONS Fasting by itself induce somatic changes, which can make the animals more vulnerable to ulcerogenic stimuli. Development of indomethacin-induced gastrointestinal lesions happened in parallel with disturbances of heart rate, core body temperature, and chronic stress-like somatic changes as well as anxiety-like behavior. We have to be more aware of the existence of the brain-gut axis and should study changes in the whole body rather than focusing on a specific organ. elevated plus maze.
Collapse
|
5
|
van der Doelen RHA, Deschamps W, D'Annibale C, Peeters D, Wevers RA, Zelena D, Homberg JR, Kozicz T. Early life adversity and serotonin transporter gene variation interact at the level of the adrenal gland to affect the adult hypothalamo-pituitary-adrenal axis. Transl Psychiatry 2014; 4:e409. [PMID: 25004389 PMCID: PMC4119224 DOI: 10.1038/tp.2014.57] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 05/06/2014] [Accepted: 05/22/2014] [Indexed: 01/17/2023] Open
Abstract
The short allelic variant of the serotonin transporter (5-HTT) promoter-linked polymorphic region (5-HTTLPR) has been associated with the etiology of major depression by interaction with early life stress (ELS). Furthermore, 5-HTTLPR has been associated with abnormal functioning of the stress-responsive hypothalamo-pituitary-adrenal (HPA) axis. Here, we examined if, and at what level, the HPA-axis is affected in an animal model for ELS × 5-HTTLPR interactions. Heterozygous and homozygous 5-HTT knockout rats and their wild-type littermates were exposed daily at postnatal days 2-14 to 3 h of maternal separation. When grown to adulthood, plasma levels of adrenocorticotropic hormone (ACTH), and the major rat glucocorticoid, corticosterone (CORT), were measured. Furthermore, the gene expression of key HPA-axis players at the level of the hypothalamus, pituitary and adrenal glands was assessed. No 5-HTT genotype × ELS interaction effects on gene expression were observed at the level of the hypothalamus or pituitary. However, we found significant 5-HTT genotype × ELS interaction effects for plasma CORT levels and adrenal mRNA levels of the ACTH receptor, such that 5-HTT deficiency was associated under control conditions with increased, but after ELS with decreased basal HPA-axis activity. With the use of an in vitro adrenal assay, naïve 5-HTT knockout rats were furthermore shown to display increased adrenal ACTH sensitivity. Therefore, we conclude that basal HPA-axis activity is affected by the interaction of 5-HTT genotype and ELS, and is programmed, within the axis itself, predominantly at the level of the adrenal gland. This study therefore emphasizes the importance of the adrenal gland for HPA-related psychiatric disorders.
Collapse
Affiliation(s)
- R H A van der Doelen
- Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands,Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands,Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein 21 (route 126), 6525 EZ Nijmegen, The Netherlands. E-mail:
| | - W Deschamps
- Department of Cellular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - C D'Annibale
- Department of Cellular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - D Peeters
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands,Department of Cellular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - R A Wevers
- Department of Laboratory Medicine, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - D Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - J R Homberg
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - T Kozicz
- Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
6
|
Zelena D, Pintér O, Langnaese K, Richter K, Landgraf R, Makara GB, Engelmann M. Oxytocin in Brattleboro rats: increased synthesis is contrasted by blunted intrahypothalamic release from supraoptic nucleus neurones. J Neuroendocrinol 2013; 25:711-8. [PMID: 23656537 DOI: 10.1111/jne.12047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/08/2013] [Accepted: 05/06/2013] [Indexed: 11/28/2022]
Abstract
Adult male Brattleboro rats were used to investigate the impact of the congenital absence of vasopressin on the release pattern of oxytocin (OXT) within the hypothalamic supraoptic nucleus (SON) in response to a 10-min forced swimming session and osmotic stimulation. Both immunohistochemical and in situ hybridisation data suggest that vasopressin-deficient animals have more oxytocin-synthesising neurones in the SON than homozygous wild-type controls. Unexpectedly, both forced swimming and peripheral osmotic stimulation resulted in a blunted release profile of oxytocin within the SON of vasopressin-deficient rats compared to controls. A similar intranuclear OXT response to direct osmotic stimulation of the SON by retrodialysis with hypertonic Ringer's solution in both genotypes confirmed the capability of SON neurones to locally release oxytocin in vasopressin-deficient rats, indicating an altered processing of information originating from multisynaptic inputs rather than a deficit in release capacity. Taken together with data obtained in previous studies, the present findings provide evidence suggesting that autocrine and paracrine signalling of magnocellular neurones differs within the paraventricular nucleus and the SON. Thus, significant alterations in intra-SON oxytocin mRNA levels cannot easily be extrapolated to intranuclear release profiles and the local signal intensity of this neuropeptide after physiological stimulation.
Collapse
Affiliation(s)
- D Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | | | | | | | | | | | | |
Collapse
|
7
|
Jain SK, Zelena D. Role of ionotropic glutamate receptors in the control of prolactin secretion by other neurotransmitters and neuropeptides at the level of the pituitary. Endocr Regul 2013; 47:65-74. [PMID: 23641787 DOI: 10.4149/endo_2013_02_65] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Although prolactin (PRL) plays an important role in the milk production, it has also many other functions. PRL secretion can be inhibited by dopamine and stimulated by serotonin, thyrotropin releasing hormone (TRH), and vasoactive intestinal peptide (VIP). However, the exact mechanisms of PRL regulation are still not fully understood. Glutamate is also a potent elevator of PRL secretion. It has several receptors: ionotropic NMDA (N-methyl-D-aspartate) and non-NMDA as well as metabotropic receptors. Our interest was to find out whether endogenous glutamate may act at the hypophyseal level and affect the PRL regulating neurotransmitters (dopamine, serotonin, TRH, VIP). METHODS MK-801 as NMDA blocker and GYKI52466 as a non-NMDA antagonist were used in this study. For dopamine and serotonin experiments intraperitoneal drug administration and blood sampling were applied. On the other hand, TRH and VIP effect on PRL secretion was studied in in vitro conditions by incubating them with a half 300*300nm choppered anterior pituitary gland of the adult male rats. RESULTS The basal PRL levels were not influenced by the glutamate antagonists used either alone or combined in both in vivo and in vitro conditions. We failed to reveal interaction between dopamine-, serotonin-, and TRH-induced PRL rise and antagonists treatment. MK-801 had a significant inhibitory effect on VIP-induced PRL changes. CONCLUSIONS Our data confirmed the regulatory role of dopamine, serotonin, and TRH on PRL secretion, however, the interaction between these and glutamatergic systems was not confirmed, at least not via the ionotropic receptors. On the other hand, the endogenous glutamate can through the NMDA receptor subtype contribute to the VIP-induced PRL secretion at the level of the anterior pituitary. This regulation may be especially important during suckling and stress response when rapid release of PRL is required.
Collapse
Affiliation(s)
- S K Jain
- Department of Zoology, Dr H.S. Gour University, India
| | | |
Collapse
|
8
|
|
9
|
Derks NM, Pintér O, Zuure W, Ledent C, Watanabe M, Molnár CS, Wei Y, Roubos EW, Wu S, Hrabovszky E, Zelena D, Kozicz T. Cannabinoid modulation of midbrain urocortin 1 neurones during acute and chronic stress. J Neuroendocrinol 2012; 24:1447-61. [PMID: 22734681 DOI: 10.1111/j.1365-2826.2012.02355.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Neurones in the centrally projecting Edinger-Westphal nucleus (EWcp) are the main site of urocortin 1 (Ucn1) synthesis in the mammalian brain, and are assumed to play a role in the stress response of the animal. Because endocannabinoid signalling has also been strongly implicated in stress, we hypothesised that endocannabinoids may modulate the functioning of the urocortinergic EWcp. First, using in situ hybridisation, we demonstrated cannabinoid receptor 1 (CB1R) mRNA expression in mouse EWcp-neurones that were Ucn1-negative. Dual- and triple-label immunocytochemistry revealed the presence of CB1R in several GABA-immunopositive fibres juxtaposed to EWcp-Ucn1 neurones. To test functional aspects of such an anatomical constellation, we compared acute (1 h of restraint) and chronic (14 days of chronic mild stress) stress-induced changes in wild-type (WT) and CB1R knockout (CB1R-KO) mice. Acute and especially chronic stress resulted in an increase in Ucn1 content of the EWcp, which was attenuated in CB1R-KO mice. CB1R-KO mice had higher basal and chronic stress-induced adrenocorticotrophin and corticosterone levels and were more anxious on the elevated plus-maze versus WT. Collectively, our results show for the first time EWcp-Ucn1 neurones are putatively innervated by endocannabinoid sensitive, inhibitory, GABAergic afferents. In addition, we provide novel evidence that the absence of the CB1 receptor alters the Ucn1 mRNA and peptide levels in EWcp neurones, concomitant with an augmented stress response and increased anxiety-like behaviour.
Collapse
MESH Headings
- Acute Disease
- Animals
- Anxiety/etiology
- Anxiety/genetics
- Anxiety/metabolism
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Chronic Disease
- Endocannabinoids/pharmacology
- Hypothalamo-Hypophyseal System/drug effects
- Hypothalamo-Hypophyseal System/metabolism
- Hypothalamo-Hypophyseal System/physiology
- Male
- Mesencephalon/drug effects
- Mesencephalon/metabolism
- Mesencephalon/pathology
- Mice
- Mice, Knockout
- Neurons/drug effects
- Neurons/metabolism
- Neurons/physiology
- Pituitary-Adrenal System/drug effects
- Pituitary-Adrenal System/metabolism
- Pituitary-Adrenal System/physiology
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Stress, Psychological/genetics
- Stress, Psychological/metabolism
- Stress, Psychological/pathology
- Urocortins/genetics
- Urocortins/metabolism
- gamma-Aminobutyric Acid/genetics
- gamma-Aminobutyric Acid/metabolism
Collapse
Affiliation(s)
- N M Derks
- Department of Cellular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Centre for Neuroscience, Radboud University Nijmegen, Nijmegen, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
Nowadays, the endocannabinoid-regulated processes are in the focus of interest, among others, for the treatment of stress-related disorders. In this minireview, we attempt to give some possible explanations for the conflicting results of the cannabinoidergic regulation of the hypothalamo-pituitary-adrenocortical (HPA) axis and related disorders, drawing attention to the complexity of the endocannabinoid system. The endocannabinoid system is a part of an intricate network of lipid pathways and consists of the cannabinoid receptors, their endogenous ligands, and the enzymes catalyzing their formation and degradation. The stress research is focused almost exclusively on the anandamide and 2-arachidonyl glycerol, and the cannabinoid 1 receptor. However, physiological, pathological, and pharmacological perturbations of the interconnected lipid pathways have a profound effect on the regulation of the endocannabinoid signaling system. For example, diet may substantially influence the lipid composition of the body. Recent studies have indicated that beside cannabinoid 1 receptor, the endocannabinoids may act on the cannabinoid 2, peroxisome proliferator-activated, and transient receptor potential of vanilloid type-1 receptors, too. All of these receptors are implicated in the development of stress-related disorders. However, it has to be mentioned that degradation of the endocannabinoids may result in the production of active compounds as well. Since endocannabinoids have a widespread distribution in the body, they may influence a phenomenon at several points. Different effects (stimulatory or inhibitory) at different levels of endocannabinoids (e.g. hypothalamus, hypophysis, adrenal gland in the case of HPA axis) may explain some of their unequivocal results.
Collapse
Affiliation(s)
- I Barna
- Hungarian Academy of Science, Budapest, Hungary
| | | |
Collapse
|
11
|
Könczöl K, Pintér O, Ferenczi S, Varga J, Kovács K, Palkovits M, Zelena D, Tóth ZE. Nesfatin-1 exerts long-term effect on food intake and body temperature. Int J Obes (Lond) 2012; 36:1514-21. [PMID: 22290539 DOI: 10.1038/ijo.2012.2] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To determine whether the anorexigenic peptide, nesfatin-1 affects energy expenditure, and to follow the time course of its effects. DESIGN Food intake duration, core body temperature, locomotor activity and heart rate of rats were measured by telemetry for 48 h after a single intracerebroventricular injection of 25 or 100 pmol nesfatin-1 applied in the dark or the light phase of the day. Body weight, food and water intake changes were measured daily. Furthermore, cold-responsive nesfatin-1/NUCB2 neurons were mapped in the brain. RESULTS Nesfatin-1 reduced duration of nocturnal food intake for 2 days independently of circadian time injected, and raised body temperature immediately, or with little delay depending on the dose and circadian time applied. The body temperature remained higher during the next light phases of the 48 h observation period, and the circadian curve of temperature flattened. After light phase application, the heart rate was elevated transiently. Locomotion did not change. Daily food and water intake, as well as body weight measurements point to a potential decrease in all parameters on the first day and some degree of compensation on the second day. Cold-activated (Fos positive) nesfatin-1/NUCB2 neurones have been revealed in several brain nuclei involved in cold adaptation. Nesfatin-1 co-localised with prepro-thyrotropin-releasing hormone in cold responsive neurones of the hypothalamic paraventricular nucleus, and in neurones of the nucleus raphe pallidus and obscurus that are premotor neurones regulating brown adipose tissue thermogenesis and skin blood flow. CONCLUSION Nesfatin-1 has a remarkably prolonged effect on food intake and body temperature. Time course of nesfatin-1's effects may be varied depending on the time applied. Many of the nesfatin-1/NUCB2 neurones are cold sensitive, and are positioned in key centres of thermoregulation. Nesfatin-1 regulates energy expenditure a far more potent way than it was recognised before making it a preferable candidate anti-obesity drug.
Collapse
Affiliation(s)
- K Könczöl
- Neuromorphological and Neuroendocrine Research Laboratory, Department of Anatomy, Histology and Embryology, Semmelweis University and the Hungarian Academy of Sciences, Budapest, Hungary.
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Filaretova LP, Bagaeva TR, Morozova OY, Zelena D. The healing of NSAID-induced gastric lesion may be followed by small intestinal and cardiovascular side effects. J Physiol Pharmacol 2011; 62:619-625. [PMID: 22314564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 11/23/2011] [Indexed: 05/31/2023]
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among some of the most commonly used medications. Serious adverse effects induced by NSAIDs may occur not only in the upper gastrointestinal tract, but in the small intestine and cardiovascular system. However, these side effects are studied and investigated separately. Here we tested the hypothesis that the healing of indomethacin-induced gastric erosion may be followed by small intestinal and cardiovascular adverse effects. First we examined the development of gastrointestinal lesions 4-24-48-72 h after a single indomethacin (35 mg/kg s.c.) injection given to fasted male rats (refeeding after 4 h). Then with a telemetric device heart rate, core body temperature and locomotion changes were recorded in the freely moving animals for 72 h after indomethacin or its vehicle injection (control). Indomethacin produced hemorrhagic erosion in the glandular stomach 4 h after its administration which was almost completely healed 48 h later. Parallel to the healing a gradual increase of injury to the small intestine became apparent. The control rats' heart rate, core body temperature and locomotion all agreed with a normal circadian rhythm. However, the circadian cycle of rats treated with indomethacin in 24 h after its administration was disrupted: their heart rate rose to it's maximal level and their locomotion and core temperature values fell to their minimal. These results suggest that the healing of gastric erosion induced by a single indomethacin injection may be followed by other pathological events outside of the stomach, among which there may be intestinal injury and a loss of a normal circadian cycle of heart rate as well as body temperature and locomotion.
Collapse
Affiliation(s)
- Ludmila P Filaretova
- Laboratory of Experimental Endocrinology, Pavlov Institute of Physiology, St. Petersburg, Russia.
| | | | | | | |
Collapse
|
13
|
Zelena D, Barna I, Pintér O, Klausz B, Varga J, Makara GB. Congenital absence of vasopressin and age-dependent changes in ACTH and corticosterone stress responses in rats. Stress 2011; 14:420-30. [PMID: 21438769 DOI: 10.3109/10253890.2011.552991] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The hypothalamic components of the hypothalamo-pituitary-adrenal axis (HPA) are corticotropin-releasing hormone (CRH) and vasopressin. To test the hypothesis that HPA regulation changes with age, we compared ether and bacterial lipopolysaccharide (LPS) injection induced stress reactions in adult and 10-day-old Brattleboro rats, which naturally lack vasopressin owing to mutation of the gene (di/di). The LPS stimulus was used also with V(1b) receptor antagonist pretreatment (SSR149415). In adult di/di or V(1b) pretreated rats, we observed normal pituitary and adrenocortical secretory responses, while in all 10-day-old rats stress-induced serum corticosterone increases were marked, but adrenocorticotropin (ACTH) increases were significantly smaller. Compared to control pups the adenohypophysis of the 10-day-old di/di rats responded normally to CRH, but their adrenal glands were hyper-responsive to ACTH, while in adults there was greater secretion at both levels with no difference between the genotypes. The serum transcortin level was higher in adults than pups, with the di/di pups having higher transcortin levels than controls. Hence, using the same stressors in adults and pups with both a genetic model and pharmacological pretreatment, we have shown that the role of vasopressin in ACTH regulation is more important during the neonatal period than in adulthood. Blunted hypophysial sensitivity to CRH and similar adrenal gland sensitivity to ACTH in the pups compared to adults suggest that hypothalamic factors could be responsible for the neonatal stress hyporesponsive period.
Collapse
Affiliation(s)
- D Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
| | | | | | | | | | | |
Collapse
|
14
|
Jain SK, Zelena D. Gender specific influence of endogenous glutamate release on stress-induced fear in rats. Endocr Regul 2011; 45:13-21. [PMID: 21314206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
OBJECTIVE Stress, fear and anxiety are among major public health concerns. The role of glutamate in these processes is becoming more recognized with promising new drug targets. The aim of this study was to establish the gender specificity of a possible treatment of fear by glutamate antagonists in correspondence with changes in stress-hormone release. METHODS Footshock-induced fear was used as an anxiogenic situation in rats. A combination of two ionotrop receptor antagonists such as MK-801 (dizocilpine; 0.2 mg/kg) for NMDA (N-methyl-D-aspartic acid) and GYKI 52466 (benzodiazepine derivative; 10 mg/kg) for AMPA/kainate receptors were used for 5 days following the hypothesis that they potentiate each other the main action, but at the same time the side effects may be minimized. RESULTS Female rats tried to avoid the electrical stimulus more actively than males, as they spent more time with exploration and jumping and less time with freezing or rest. Ionotropic glutamate receptor antagonists have anxiolytic action. MK-801 was more effective in females, as it prevented the footshock-induced freezing per se, while in males it was effective only in combination with GyKI 52466. The locomotor side effect of MK-801 was not visible after repeated administration. The freezing behavior was positively correlated with the changes in prolactin but not with adrenocorticotropin levels. CONCLUSIONS We proved the involvement of endogenous glutamate neurotransmission in stress-induced fear. Therapeutical usage may involve a combination of different receptor antagonists. Special attention should be paid to the gender, as females seem to be more sensitive, therefore they require smaller doses. During the treatment the prolactin levels should be monitored.
Collapse
Affiliation(s)
- S K Jain
- Department of Zoology, Dr. H. S. Gour University, Sagar, India.
| | | |
Collapse
|
15
|
Bundzikova J, Pirnik Z, Zelena D, Mikkelsen JD, Kiss A. The α2-adrenoceptors do not modify the activity of tyrosine hydroxylase, corticoliberine, and neuropeptide Y producing hypothalamic magnocellular neurons ion the Long Evans and Brattleboro rats. J Physiol Pharmacol 2010; 61:391-398. [PMID: 20814066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 07/15/2010] [Indexed: 05/29/2023]
Abstract
The hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei are activated by body salt-fluid variations. Stimulation of alpha(2)-adrenoceptors by an agonist-xylazine (XYL) activates oxytocinergic but not vasopressinergic magnocellular neurons. In this study, tyrosine hydroxylase (TH), corticoliberine (CRH), and neuropeptide Y(NPY) magnocellular phenotypes, were analysed in response to alpha(2)-adrenoceptor manipulations and sustained hyperosmolality in vasopressin deficient homozygous Brattleboro (di/di) rats. Saline (0.9% NaCl, 0.1 ml/100g/bw), XYL (10 mg/kg/bw), atipamezole (ATIP, alpha(2)-adrenoceptors antagonist, 1 mg/kg/bw), and ATIP 5 min later followed by XYL, were applied intraperitoneally. Presence of immunolabeled Fos peptide signalized the neuronal activity. Ninety minutes after injections, the rats were anesthesized and sacrificed by transcardial perfusion with fixative. Coronal sections of 30 mum thickness double immunolabeled with Fos/neuropeptide were evaluated under light microscope. Under basal conditions, di/di in comparison with control Long Evans rats, displayed significantly higher number of TH, CRH, and NPY immunoreactive neurons in the SON and PVN (except NPY cells in PVN) and more than 90%, 75%, and 86% of TH, NPY, and CRH neurons, respectively, displayed also Fos signal in the SON. XYL did not further increase the number of Fos in the PVN and SON and ATIP failed to reduce the stimulatory effect of hypertonic saline in all neuronal phenotypes studied. Our data indicate that hyperosmotic conditions significantly influence the activity of TH, CRH, and NPY magnocellular neuronal phenotypes, but alpha(2)-adrenoceptors do not play substantial role in their regulation during osmotic challenge induced by AVP deficiency.
Collapse
Affiliation(s)
- J Bundzikova
- Laboratory of Functional Neuromorphology, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | | | | | | | | |
Collapse
|
16
|
Barna I, Csabai K, Makara G, Zelena D. CANNABINOID-MEDIATED REGULATION OF THE HYPOTHALAMO-PITUITARY-ADRENAL AXIS in rats: AGE DEPENDENT ROLE OF VASOPRESSIN. Endocr Regul 2009; 43:13-21. [DOI: 10.4149/endo_2009_01_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
|
17
|
Mlynarik M, Zelena D, Bagdy G, Makara GB, Jezova D. Signs of attenuated depression-like behavior in vasopressin deficient Brattleboro rats. Horm Behav 2007; 51:395-405. [PMID: 17258216 DOI: 10.1016/j.yhbeh.2006.12.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 11/17/2006] [Accepted: 12/13/2006] [Indexed: 11/23/2022]
Abstract
Vasopressin, a peptide hormone functioning also as a neurotransmitter, neuromodulator and regulator of the stress response is considered to be one of the factors related to the development and course of depression. In the present study, we have tested the hypothesis that congenital deficit of vasopressin in Brattleboro rats leads to attenuated depression-like behavior in tests modeling different symptoms of depression. In addition, hypothalamic-pituitary-adrenocortical axis activity was investigated. Vasopressin deficient rats showed signs of attenuated depression-like behavior in forced swimming and sucrose preference tests, while their behavior on elevated plus maze was unchanged. Vasopressin deficiency had no influence on basal levels of ACTH and corticosterone and had only mild impact on hormonal activation in response to forced swimming and plus-maze exposure. However, vasopressin deficient animals showed higher level of dexamethasone induced suppression of corticosterone response to restraint stress and higher basal levels of corticotropin-releasing hormone mRNA in the hypothalamic paraventricular nucleus. In conclusion, present data obtained in vasopressin deficient rats show that vasopressin is involved in the development of depression-like behavior, in particular of the coping style and anhedonia. Moreover, behavioral and endocrine responses were found to be dissociated. We suggest that brain vasopressinergic circuits distinct from those regulating the HPA axis are involved in generating depression-like behavior.
Collapse
Affiliation(s)
- M Mlynarik
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, Bratislava 83306, Slovakia
| | | | | | | | | |
Collapse
|
18
|
Barna I, Zelena D, Arszovszki AC, Ledent C. The role of endogenous cannabinoids in the hypothalamo-pituitary-adrenal axis regulation: in vivo and in vitro studies in CB1 receptor knockout mice. Life Sci 2004; 75:2959-70. [PMID: 15454346 DOI: 10.1016/j.lfs.2004.06.006] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2004] [Accepted: 06/14/2004] [Indexed: 11/26/2022]
Abstract
Exogenous cannabinoids affect multiple hormonal systems including the hypothalamo-pituitary-adrenocortical (HPA) axis. These data suggest that endogenous cannabinoids are also involved in the HPA control; however, the mechanisms underlying this control are poorly understood. We assessed the role of endogenous cannabinoids in the regulation of the HPA-axis by studying CB1 receptor knockout (KO) and wild type (WT) mice. Basal and novelty stress-induced plasma levels of adrenocorticotropin (ACTH) and corticosterone were higher in CB1-KO than in WT mice. We investigated the involvement of the pituitary in the hormonal effects of CB1 gene disruption by studying the in vitro release of ACTH from anterior pituitary fragments using a perifusion system. Both the basal and corticotropin releasing hormone (CRH)-induced ACTH secretion were similar in CB1-KO and WT mice. The synthetic glucocorticoid, dexamethasone suppressed the CRH-induced ACTH secretion in both genotypes; thus, the negative feedback of ACTH secretion was not affected by CB1 gene disruption. The cannabinoid agonist, WIN 55,212-2 had no effects on basal and CRH-stimulated ACTH secretion by anterior pituitary slices. In our hands, the disruption of the CB1 gene lead to HPA axis hyperactivity, but the pituitary seems not to be involved in this effect. Our data are consistent with the assumption that endogenous cannabinoids inhibit the HPA-axis via centrally located CB1 receptors, however the understanding of the exact underlying mechanism needs further investigation.
Collapse
Affiliation(s)
- I Barna
- Institute of Experimental Medicine, 1083 Budapest, P.O. Box 67, Hungary.
| | | | | | | |
Collapse
|
19
|
Abstract
The role of vasopressin, cosecreted with corticotropin-releasing hormone (CRH), in stress is debated, because both normal as well as reduced adrenocorticotropin hormone (ACTH) rise to an acute challenge has been reported in Brattleboro rats genetically lacking vasopressin (di/di). Because di/di pups could be born either from di/+ (heterozygous) or from di/di mothers, and maternal influence is known to modify adult responsiveness, we investigated whether the influence of maternal genotype could explain the variability. Adult rats from mothers with different genotypes were stressed with 60 min restraint and trunk blood was collected for measuring hormone content by radioimmunoassay at the end of stress. All offspring of di/+ mothers had similar ACTH responses to restraint, while the di/di rats born to, and raised by di/di mothers showed reduced ACTH reactivity to restraint. The di/di rats showed elevated water turnover and required a daily cage cleaning every day, which meant frequent handling. To offset the role of handling, all rats had daily cage cleaning in the next series, but the results were the same as in the first series. To investigate whether lactation, the behaviour of the mother or some other factor during the pregnancy is responsible for the differences, pups from di/+ dams were raised by di/di foster mothers and vice versa. We found that the genotype of parental mother is more important than that of the foster mother. The corticosterone and prolactin elevation normally seen after acute stress was unchanged by family history, maternal or personal genotype. Furthermore, in studies with mutant animals, the rearing conditions should be controlled by the experimenter. In experiments with Brattleboro rats, the use of homozygous and heterozygous rats from the same litters of di/+ dams and di/di males is recommended. Our results suggest that vasopressin is not indispensable for ACTH release, and that the di/di genotype of the parental mother can decrease the stress reactivity of the di/di Brattleboro rats.
Collapse
Affiliation(s)
- D Zelena
- Hungarian Academy of Sciences, Institute of Experimental Medicine, Budapest, Hungary
| | | | | |
Collapse
|
20
|
Zelena D, Mergl Z, Foldes A, Kovács KJ, Tóth Z, Makara GB. Role of hypothalamic inputs in maintaining pituitary-adrenal responsiveness in repeated restraint. Am J Physiol Endocrinol Metab 2003; 285:E1110-7. [PMID: 14534078 DOI: 10.1152/ajpendo.00219.2003] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of hypothalamic structures in the regulation of chronic stress responses was studied by lesioning the mediobasal hypothalamus or the paraventricular nucleus of hypothalamus (PVH). Rats were acutely (60 min) and/or repeatedly (for 7 days) restrained. In controls, a single restraint elevated the plasma adrenocorticotropin (ACTH), corticosterone, and prolactin levels. Repeated restraint produced all signs of chronic stress, including decreased body and thymus weights, increased adrenal weight, basal corticosterone levels, and proopiomelanocortin (POMC) mRNA expression in the anterior pituitary. Some adaptation to repeated restraint of the ACTH response, but not of other hormonal responses, was seen. Lesioning of the mediobasal hypothalamus abolished the hormonal response and POMC mRNA activation to acute and/or repeated restraint, suggesting that the hypothalamo-pituitary-adrenal axis activation during repeated restraint is centrally driven. PVH lesion inhibited the ACTH and corticosterone rise to the first restraint by approximately 50%. In repeatedly restrained rats with PVH lesion, the ACTH response to the last restraint was reduced almost to basal control levels, and the elevation of POMC mRNA level was prevented. PVH seems to be important for the repeated restraint-induced ACTH and POMC mRNA stimulation, but it appears to partially mediate other restraint-induced hormonal changes.
Collapse
Affiliation(s)
- D Zelena
- Laboratory of Stress Research, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1450 Budapest, Hungary
| | | | | | | | | | | |
Collapse
|
21
|
Makara GB, Harbuz MS, Coventry TL, Jessop DS, Zelena D, Lightman SL. The effect of hypothalamic lesions on hypothalamo-pituitary-adrenal axis activity and inflammation in adjuvant-induced arthritis. Stress 2001; 4:25-37. [PMID: 22432125 DOI: 10.3109/10253890109001141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Adjuvant-induced arthritis (AA) was induced in control and in hypothalamic lesioned Piebald-Viral-Glaxo (PVG) rats. Following discrete paraventricular nucleus (PVN) lesions plasma corticosterone was increased 14 days after adjuvant injection as in controls, when hind paw inflammation was apparent. PVN lesion did not affect the severity of inflammation.In contrast, following medial basal hypothalamus (MBH) lesions adjuvant did not increase corticosterone levels and the increase in paw volume at day 14 was potentiated. Basal proopiomelanocortin(POMC) mRNA expression in the anterior lobe was unchanged by PVN lesions and decreased by MBH lesions. AA increased POMC mRNA in controls and in both PVN and MBH lesioned rats. After complete MBH lesion, surviving anterior pituitary tissue maintained morning levels of corticosterone.Thus, AA may activate the hypothalamo-pituitary-adrenal axis without the mediation of PVN neurones projecting to the median eminence. However, the loss of the corticosterone response to AA and the increase in severity of inflammation in the MBH lesioned rats suggests a central (non-PVN) component mediates effects of inflammation. Furthermore, the increase in POMC mRNA in the MBH lesioned AA rats suggests that part of this process is not mediated by releasing factors in the hypothalamo-hypophysial portal system, and that extrahypothalamic(peripheral) mediators act on the pituitary during chronic inflammation.
Collapse
Affiliation(s)
- G B Makara
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary. makara8 koki.hu
| | | | | | | | | | | |
Collapse
|
22
|
Zelena D, Makara GB, Jezova D. Simultaneous blockade of two glutamate receptor subtypes (NMDA and AMPA) results in stressor-specific inhibition of prolactin and corticotropin release. Neuroendocrinology 1999; 69:316-23. [PMID: 10343172 DOI: 10.1159/000054433] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Many neurons express simultaneously two or more isotypes of glutamate receptors, so that pharmacological modulation of more than one receptor may be necessary to reveal the role of glutamate in mediating physiological processes. The present studies were aimed at evaluating involvement of endogenous glutamate in triggering plasma prolactin (PRL) and adrenocorticotropic hormone (ACTH) levels in response to three different stress stimuli (footshock, immobilization and ether stress). Blockade of glutamate receptor subtypes was achieved by the administration of the NMDA antagonist dizocilpine (MK-801, 0.2 mg/kg) and the selective AMPA antagonist GYKI 52466 (10 mg/kg). Rats were pretreated for 4-5 days and then exposed to stressful stimulation. Basal hormone levels were not affected by the antagonists. In male rats, combined, but not separate blockade of NMDA and AMPA/kainate subtypes of glutamate receptors prevented the rise in plasma PRL in response to footshock stress. In female rats, footshock-induced PRL release was inhibited even by separate blockade of NMDA receptors by dizocilpine, suggesting that the PRL system of females is more sensitive to the effect of NMDA antagonists than that of males. None of the treatments affected PRL release during immobilization or ether stress. Simultaneous blockade of NMDA and AMPA receptor subtypes resulted in a mild inhibition of immobilization-induced ACTH release without any effect on ACTH response to footshock or ether stress. The data suggest that involvement of glutamatergic pathways in neuroendocrine response during stress is selective for discrete stress stimuli and stress hormones. In addition a concerted action of glutamate on both NMDA and non-NMDA receptor subtypes is involved in the control of PRL release during footshock stress.
Collapse
Affiliation(s)
- D Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | | | | |
Collapse
|
23
|
Abstract
The effect of different alpha 2-adrenoreceptor subtype agonists and antagonists on adrenocorticotrop hormone (ACTH) and beta-endorphin release induced by ether stress was examined. Ether inhalation-induced ACTH and beta-endorphin increase was inhibited by i.c.v. administration of 30 micrograms but not 1 and 10 micrograms clonidine (alpha 2-adrenoreceptor agonist). I.c.v. oxymetazoline (alpha 2A-adrenoreceptor agonist; 1-10-30 micrograms) or the alpha 1-agonist methoxamine (100 micrograms/rat) failed to inhibit the stress-induced rise. Pretreatment with the alpha 1/alpha 2B.C-antagonist prazosin (0.5 mg/kg, i.p.) prevented the effect of clonidine on the ether stress, while the alpha 1/alpha 2A-antagonist WB-4101 (0.5 mg/kg, i.p.) was unable to counteract the inhibitory effect of clonidine. Prazosin alone had no effect on the ether-induced plasma ACTH and beta-endorphin elevation. These results suggest that noradrenaline in the central nervous system may inhibit the stress-induced hypothalamo-pituitary-axis and pituitary beta-endorphin activation via alpha 2B.C-adrenoceptor subtypes and prazosin may antagonize its effect on these receptors.
Collapse
Affiliation(s)
- D Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | | | | | | |
Collapse
|
24
|
Abstract
Stress effects in humans depend on stress type, intensity, and duration. Animal models of social stress serve as good ways to mimic stress experienced in humans. However, the available stress paradigms pay little attention to the relationship between the intensity and the type of social stressors. The aim of the present work is to study behavioral and endocrinological consequences of social stress by varying the intensity and type of agonistic social contacts. Subjects were exposed to the attacks of an experienced fighter resident rat once a day for 4 consecutive days. Mild versus strong effects were studied by varying the length of daily confrontations (30 min vs. 4 h). The type of social confrontations was varied by ceasing or maintaining sensory contacts among contestants between encounters. Endocrinological variables were measured on the 5th day. Anxiety was assessed by means of the elevated plus-maze. The stress state depended on the length of daily encounters: 30-min encounters did not, whereas 4-h encounters did result in weight loss and chronic elevation of plasma corticosterone. The type of contacts between subjects and dominants also affected the resulting stress state: adrenal hypertrophy was obtained only when contacts between contestants were maintained between encounters. Although the mildest stress procedure (30-min encounters on 4 consecutive days) did not affect endocrinological variables, it resulted in subtle behavioral modifications that changed the anxiety-related effects of additional acute stressors. Thus, anxiety-related behavioral changes resulting from repeated mild stressors may be hidden factors that can have long-term consequences on the development of anxiety-like behavioral deficits. Results outline the necessity of studying the effects of social stressors of different intensities and different types.
Collapse
Affiliation(s)
- D Zelena
- Institute of Experimental Medicine, Hungarian Academy of Science, Budapest
| | | | | | | |
Collapse
|
25
|
DeMaria JE, Zelena D, Vecsernyés M, Nagy GM, Freeman ME. The effect of neurointermediate lobe denervation on hypothalamic neuroendocrine dopaminergic neurons. Brain Res 1998; 806:89-94. [PMID: 9739113 DOI: 10.1016/s0006-8993(98)00740-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The contribution of tuberohypophyseal and periventricular-hypophyseal dopaminergic neurons to the regulation of the secretion of prolactin (PRL) has yet to be clarified. In this study, we used pituitary stalk compression to disrupt hypothalamic neural input to the neurointermediate lobe (NIL). Neurointermediate lobe denervation (NIL-D) selectively disrupts the axons of tuberohypophyseal and periventricular-hypophyseal dopaminergic neurons, while leaving tuberoinfundibular dopaminergic neurons and the vascular supply of the pituitary gland intact. NIL-D was performed in ovariectomized (OVX) rats. The concentration of DA and 3,4-dihydroxyphenylacetic acid (DOPAC) in the median eminence (ME) and various regions of the pituitary gland of OVX and OVX+NIL-D rats were measured by HPLC-EC. The concentration of PRL, alpha-melanocyte stimulating hormone (alpha-MSH), and luteinizing hormone (LH) in serum were determined by radioimmunoassay. Successful NIL-D was confirmed by increased water intake. One week after NIL-D, serum PRL and alpha-MSH were elevated, but there was no change in the concentration of LH in serum. The concentration of DA was increased in the median eminence (ME), decreased in the outer zone of the anterior lobe (AL-OZ), as well as the intermediate (IL) and neural lobes (NL), and remained unchanged in the inner zone of the anterior lobe (AL-IZ). The concentration of DOPAC was increased in the ME and NL, decreased in the IL, and remained unchanged in both the AL-IZ and AL-OZ. These data confirm that pituitary stalk compression denervates the NIL. Moreover, decreases in the concentration of DA in the IL and AL-OZ, coupled with elevation of serum PRL and alpha-MSH indicate that DA from the NIL contributes to the increased inhibition of the secretion of PRL and alpha-MSH in OVX rats.
Collapse
Affiliation(s)
- J E DeMaria
- Department of Biological Science, 208 Biomedical Research Facility, Program in Neuroscience, The Florida State University, Tallahassee, FL 32306-4340, USA
| | | | | | | | | |
Collapse
|
26
|
Haller J, Abrahám I, Zelena D, Juhász G, Makara GB, Kruk MR. Aggressive experience affects the sensitivity of neurons towards pharmacological treatment in the hypothalamic attack area. Behav Pharmacol 1998; 9:469-75. [PMID: 9832932 DOI: 10.1097/00008877-199809000-00010] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Early investigators of brain stimulation-evoked complex behaviours (attack, escape, feeding, self-grooming, sexual behaviour) reported that experience may affect the behavioural outcome of brain stimulation. This intriguing example of functional neuronal plasticity was later totally neglected. The present experiment investigated the behavioural outcome of in vivo microdialysis perfusion of the glutamate agonist kainate and/or the GABAA antagonist bicuculline into the hypothalamic attack area (HAA) of (1) animals naive to dyadic encounters; (2) animals with a recent aggressive experience (the probe being implanted 6-24 h after the last of a series of dyadic encounters); and (3) animals with an earlier aggressive experience (probe being implanted 2 weeks after the last aggressive experience). On the experimental day, rats received two 5-min infusions during a dyadic encounter lasting 35 min with an unknown opponent. Flow rate was 1.5-2 microliters/min, drug concentrations were 1.8 x 10(-5) and 1.5 x 10(-5) M for kainate and bicuculline, respectively. Behaviour was analysed before, during and after perfusions. Only the combined kainate + bicuculline treatment had significant effects on behaviour at the doses studied. A significant increase in aggressive behaviour was elicited only in animals with a recent aggressive experience, while naive animals and with an earlier experience responded to the treatments by grooming. These results appear to support early observations indicating that one important aspect of brain stimulation effects is previous experience.
Collapse
Affiliation(s)
- J Haller
- Institute of Experimental Medicine, Budapest, Hungary.
| | | | | | | | | | | |
Collapse
|
27
|
Zelena D, Jezova D, Acs Z, Makara GB. Monosodium glutamate lesions inhibit the N-methyl-D-aspartate-induced growth hormone but not prolactin release in rats. Life Sci 1998; 62:2065-72. [PMID: 9627105 DOI: 10.1016/s0024-3205(98)00178-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Large doses of glutamate administered to newborn rats damage permanently the neurones in the hypothalamic arcuate nucleus containing the growth hormone releasing hormone and the prolactin inhibiting dopamine neuron cell bodies. Since adult animals that underwent neonatal glutamate treatment still have a relatively well functioning growth hormone and prolactin system, we tested whether in the adults the excitatory amino acid sensibility is changed. After i.v. injection of different doses (10 or 30 mg/kg) of N-methyl-D-aspartate (excitatory amino acid receptor subtype agonist) growth hormone levels were significantly increased in the control groups but there was no rise in neonatally glutamate treated male and female rats. The level of prolactin was increased by N-methyl-D-aspartate, too, but the glutamate treatment had no effect on the rise. Our study suggests that systemic administration of N-methyl-D-aspartate increases plasma growth hormone level by activating the growth hormone releasing cells in the arcuate nucleus, but the intact tuberoinfundibular dopaminergic pathway is not essential for its prolactin stimulatory effect.
Collapse
Affiliation(s)
- D Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest
| | | | | | | |
Collapse
|
28
|
Rabadan-Diehl C, Makara G, Kiss A, Lolait S, Zelena D, Ochedalski T, Aguilera G. Regulation of pituitary V1b vasopressin receptor messenger ribonucleic acid by adrenalectomy and glucocorticoid administration. Endocrinology 1997; 138:5189-94. [PMID: 9389500 DOI: 10.1210/endo.138.12.5580] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Regulation of the number of pituitary vasopressin (VP) receptors plays an important role in controlling pituitary responsiveness during alterations of the hypothalamic pituitary adrenal axis. The mechanisms regulating these VP receptors were studied by analysis of the effects of adrenalectomy and glucocorticoid administration on V1b receptor (V1b-R) messenger RNA (mRNA) by Northern blot and by in situ hybridization in the rat. Adrenalectomy transiently decreased V1b-R mRNA levels by 18 h (77% and 62% for the 3.7-kb and 3.2-kb bands in the Northern blots, and 50% by in situ hybridization), returning to basal levels after 6 days. The decrease in V1b-R mRNA after 18 h adrenalectomy was fully prevented by dexamethasone (100 microg s.c.) but not by elimination of hypothalamic CRH and VP by paraventricular nucleus lesions or median eminence deafferentation. In sham-operated rats, dexamethasone increased receptor mRNA by 50% after 6 days. In contrast to Sprague-Dawley rats, in Brattleboro rats (di/di), which lack hypothalamic VP, adrenalectomy caused a sustained decrease in V1b-R mRNA levels (<50% of controls by 6 days). The data show that pituitary V1b-R mRNA is positively regulated by glucocorticoids and that the recovery of V1b-R mRNA levels after prolonged adrenalectomy is probably mediated by VP. In addition, the data suggest that the down-regulation of VP binding after long-term adrenalectomy is due to posttranscriptional events rather than to changes in V1b-R mRNA.
Collapse
Affiliation(s)
- C Rabadan-Diehl
- Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | | | | | |
Collapse
|
29
|
Rabadan-Diehl C, Makara G, Kiss A, Zelena D, Aguilera G. Regulation of pituitary corticotropin releasing hormone (CRH) receptor mRNA and CRH binding during adrenalectomy: role of glucocorticoids and hypothalamic factors. J Neuroendocrinol 1997; 9:689-97. [PMID: 9355036 DOI: 10.1046/j.1365-2826.1997.00626.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The role of glucocorticoids and hypothalamic factors on CRH receptor expression in the pituitary were studied by analysis of the effects of adrenalectomy and suppression of CRH and VP secretion by hypothalamic lesions in the rat. Consistent with previous in situ hybridization studies, Northern blots showed that pituitary CRH receptor mRNA decreased only transiently after adrenalectomy, falling to 51% of the control levels after 18 h, and returning to control values after 6 days (112%). The early decrease was prevented by dexamethasone injection, 100 micrograms, s.c. The role of increased levels of CRH and VP in the pituitary portal circulation on the transient decrease in CRH receptor mRNA levels after adrenalectomy were studied by in situ hybridization in rats subjected in PVN lesions or median eminence deafferentation by hypothalamic anterolateral cuts (ALC). PVN lesion (12 days) or ALC (8 days) resulted in undetectable irCRH and VP in the external zone of the median eminence and had no effect on basal levels of pituitary POMC mRNA, CRH binding and CRH receptor mRNA. In sham lesioned rats, adrenalectomy for 18 h or 4 days caused the expected increases in pituitary POMC hnRNA and mRNA, and decreases in CRH binding. CRH-R mRNA levels decreased by about 50% after 18 h adrenalectomy but returned to basal by 4 days. PVN lesion or ALC fully prevented the fall in CRH binding after 18 h or 4 days adrenalectomy and the increase in POMC mRNA after 4 days adrenalectomy, whereas only attenuated the decrease in CRH receptor mRNA and increase in POMC mRNA levels after 18 h adrenalectomy. Administration of a CRH antagonist did not affect CRH receptor mRNA and POMC hnRNA and mRNA indicating that residual CRH in the median eminence after hypothalamic surgery is not responsible for the effect of adrenalectomy. These studies confirm previous in situ hybridization studies showing that adrenalectomy causes transient decreases in pituitary CRH receptor mRNA levels. The data indicate that while increases in hypothalamic CRH secretion following glucocorticoid withdrawal mediate pituitary CRH receptor binding loss and the increase in POMC expression after long-term adrenalectomy, CRH only partially accounts for the early changes in CRH receptor mRNA and POMC mRNA.
Collapse
Affiliation(s)
- C Rabadan-Diehl
- Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | | | | | | | | |
Collapse
|
30
|
Tóth B, Zelena D, Szücs K, Szöör B, Gergely P. Comparative characterization of liver glycogen metabolism in rat and guinea-pig. Comp Biochem Physiol B 1992; 103:547-52. [PMID: 1458830 DOI: 10.1016/0305-0491(92)90368-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
1. Guinea-pig liver contained more phosphorylase in the active (phosphorylated) form and less synthase in the active (dephosphorylated) form when compared with rat liver. 2. Activities of cyclic AMP-dependent protein kinase and Ca(2+)-dependent phosphorylase kinase were the same in rat and guinea-pig livers. 3. Activities of phosphorylase phosphatase and synthase phosphatase in the extract and glycogen plus microsomal fraction of guinea-pig liver were significantly lower than those of rat liver. 4. The existence of inhibitor-1 in the liver of guinea-pig can maintain a lower activity of type-1 protein phosphatase, especially when inhibitor-1 is phosphorylated by cyclic AMP-dependent protein kinase.
Collapse
Affiliation(s)
- B Tóth
- Department of Medical Chemistry, University School of Medicine, Debrecen, Hungary
| | | | | | | | | |
Collapse
|