Katalin Halasy | Szent István University (original) (raw)
Papers by Katalin Halasy
The sensory pleasure of a good soup represents a complex synthesis of molecular and cellular inpu... more The sensory pleasure of a good soup represents a complex synthesis of molecular and cellular inputs of ions. Here we are focusing on the intake of potassium ions affecting the muscles along with the sensorineural science of eating a satisfying bowl of soup. Unbalanced ionic homeostasis and modified expression of ion channels is presumably involved in the inhibition of normal physiological functions. Salts are necessary components of soup with the flavorful broth that the salt complements turn out to activate another components of the sense of taste, the sense of savoury. Here we show the properties, molecular composition and pharmacological effects of potassium ions for the main channels of Kv-type, Kir and connexin channels in the ear system and the muscle components under physiological concentration of K-ions. However, the high concentration of K +-and Na +-ions evokes an aversive response, which is curiously not well understood at molecular level that respond to sour or bitter flavors. The ionic homeostasis has the main role to keep the cell tone in the muscle cells and, within all cells, what is supported by soup containing a wide variety of ions and flavors.
Connexins, Kv-type ion channels, and pannexins have a dominant role in maintaining the potassium ... more Connexins, Kv-type ion channels, and pannexins have a dominant role in maintaining the potassium ion homeostasis in the cochlea. The cellular background currents are sustained by Kir2.1 ion channels; however, their involvement in the hearing system is less clear. In this study, the mutations of gap junction proteins beta 2 (GJB2), beta 3 (GJB3) and beta 6 (GJB6) were screened in the white Caucasian population in Hungary using gene mapping and immunofluorescence methods from translated proteins of these genes—connexins on blood cells. Expression of connexins and Kir2.1 ion channels was investigated in the blood cells of deaf patients prior to cochlear implantation, and the results show significantly decreased amounts of connexin26 and connexin43. In addition, the coexpression of Kir2.1 ion channels with synapse-associated 97 proteins was partially impaired. Our investigation revealed a reduced level of Kir2.1 channels in deaf patients indicating a crucial role for the functional Shak...
Journal für Hirnforschung, 1993
The dentate gyrus has been shown to receive a laminated and target selective GABAergic input (Han... more The dentate gyrus has been shown to receive a laminated and target selective GABAergic input (Han et al., 1993; Halasy and Somogyi, 1993), but the numerical parameters of this innervation are not known. In order to establish the relative weight of GABAergic inputs to the dendritic versus somatic regions of granule cells the numerical density and proportion of GABA-immunopositive and immunonegative synaptic boutons and their postsynaptic targets were determined in the molecular and granule cell layers of the dentate gyrus using the postembedding immunogold method. The granule cell layer contained 9% of all synapses with the remaining 91% being in the molecular layer. Altogether 17% of all synaptic boutons were GABA-immunoreactive, and they formed either type 1 or type 2 synaptic junctions. About 88% of synaptic boutons in the granule cell layer and 7-8% in the molecular layer were GABA-positive. However, the numerical density (number of synapses per unit volume) of GABA-immunoreactiv...
Ophiobolins are important members of the family of phytotoxic metabolites, and they possess antit... more Ophiobolins are important members of the family of phytotoxic metabolites, and they possess antitumor, antibacterial, antifungal activities. At the same time, the knowledge on the effect of ophiobolins on ion channels is very limited. The voltage-dependent transient outward currents (Ito) are determined by kv4.2 and kv4.3 ion channels. Increasing evidence points to a role of HMGB1 and synapse-associated protein 97 (Sap97) as underlying factors related to inflammation. The Sap97 associates with kv4.x type channels in the complex and modulating their kinetic properties. Our hypothesis was that Sap97 mainly localizes in the intercalated discs of the cardiac muscle, therefore the altered expression of ion channels is presumably involved in the inhibition of normal mechanical parameters and physiological function of transient outward current (Ito). Our approach was to use purified 6-epi-ophiobolin A as effective molecular tools in the investigation of ion channels on cardiomyocytes. In t...
Pesticide Biochemistry and Physiology, 1994
Aquatic Toxicology, 1995
The in vitro and in vivo effects of the insecticides methidathion (MD) and deltamethrin (DM) on a... more The in vitro and in vivo effects of the insecticides methidathion (MD) and deltamethrin (DM) on acetylcholinesterase (AChE, EC 3.1.1.7) in different tissues were examined in adult carp (Cyprinus carpio L.). The changes in biochemical blood parameters, such as the levels of glutamic-oxaloacetic transaminase (GOT, EC 2.6.1. l), lactate dehydrogenase (LDH, EC 1.1.2.3) and glucose, were also studied in DM-treated fish. The in vitro kinetic results for both insecticides showed that the inhibition of brain AChE was of mixed type, with K,(MD) = 6.0 + 1 .O ,uM and K,(DM) = 15.6 I!I 2.4 ,BM. In vivo treatment with 2 mgll MD for 5 days caused a 70-90% decrease in the AChE activity of different organs, while treatment with 2 pg/l DM for 3 days did not result in such a drastically inhibited AChE. The relative distribution of the AChE molecular forms in the liver of MD-treated carps was significantly different from that in the control animals. The content of the G, form increased, while that of G, decreased. The extents of the differences were much lower in the other tissues investigated for both MD and DM treatments. In vivo DM treatment for 3 days caused a 20% decrease in the AChE activity of the blood serum, while the GOT and LDH activities increased 2.5-fold (72-h sample) and 1.5-fold (6-h sample) as compared with those of the control carp. The blood glucose level was 30%' higher (6-h sample) than that of the control fish. After the fish were returned to clean water, the parameters revealed that the recovery took only 2448 h. The accumulation of MD was highest in the liver and the roe, while the content of the skeletal muscle could not be detected by the methods used. No DM could be detected in any of the tissues, though the sensitivity of the measurement was 0.0005 mg/lOOO g wet tissue. Electronmicroscopy indicated subcellular changes in the hepatocytes. All the observed changes demonstrate the effects of MD and DM on different fish enzymes under laboratory conditions. The changes in AChE indicate how serious the neuronal damage is, while the other parameters relate to the stressed state of the fish.
Acta biologica Hungarica, 1987
Authors studied the fine structural characteristics of the neuromuscular junctions in the aliment... more Authors studied the fine structural characteristics of the neuromuscular junctions in the alimentary tract of phylogenetically different animal species. Nearly in each studied species the so-called close contacts were observable, where the sarcolemma and axolemma establish a junction; the gap of this contact is 10-100 nm wide, and the neurotransmitters can affect the muscles through non-synaptic release (exocytosis). The junctional gap is widest in the gut wall of earthworm: 100-200 nm. Only close contacts are to be found in the alimentary canal of snail, and here, the junctional gap is as narrow as 10-15 nm. Beside close contacts synaptic neuromuscular junctions also occur in the locust gut. Their fine structural organization refer to that of chemical synapses. As in the tench intestine both striated and smooth muscular elements can be found, motor endplates as well as close contacts take part in their innervation. Only close contacts are in the smooth muscular layer of domestic fo...
Histological studies on the marsupium of two terrestrial isopods... 81
Brain Research, Sep 1, 2010
European Journal of Neuroscience
Acta biologica Hungarica, 1987
Authors studied the fine structural characteristics of the neuromuscular junctions in the aliment... more Authors studied the fine structural characteristics of the neuromuscular junctions in the alimentary tract of phylogenetically different animal species. Nearly in each studied species the so-called close contacts were observable, where the sarcolemma and axolemma establish a junction; the gap of this contact is 10-100 nm wide, and the neurotransmitters can affect the muscles through non-synaptic release (exocytosis). The junctional gap is widest in the gut wall of earthworm: 100-200 nm. Only close contacts are to be found in the alimentary canal of snail, and here, the junctional gap is as narrow as 10-15 nm. Beside close contacts synaptic neuromuscular junctions also occur in the locust gut. Their fine structural organization refer to that of chemical synapses. As in the tench intestine both striated and smooth muscular elements can be found, motor endplates as well as close contacts take part in their innervation. Only close contacts are in the smooth muscular layer of domestic fo...
The sensory pleasure of a good soup represents a complex synthesis of molecular and cellular inpu... more The sensory pleasure of a good soup represents a complex synthesis of molecular and cellular inputs of ions. Here we are focusing on the intake of potassium ions affecting the muscles along with the sensorineural science of eating a satisfying bowl of soup. Unbalanced ionic homeostasis and modified expression of ion channels is presumably involved in the inhibition of normal physiological functions. Salts are necessary components of soup with the flavorful broth that the salt complements turn out to activate another components of the sense of taste, the sense of savoury. Here we show the properties, molecular composition and pharmacological effects of potassium ions for the main channels of Kv-type, Kir and connexin channels in the ear system and the muscle components under physiological concentration of K-ions. However, the high concentration of K +-and Na +-ions evokes an aversive response, which is curiously not well understood at molecular level that respond to sour or bitter flavors. The ionic homeostasis has the main role to keep the cell tone in the muscle cells and, within all cells, what is supported by soup containing a wide variety of ions and flavors.
Connexins, Kv-type ion channels, and pannexins have a dominant role in maintaining the potassium ... more Connexins, Kv-type ion channels, and pannexins have a dominant role in maintaining the potassium ion homeostasis in the cochlea. The cellular background currents are sustained by Kir2.1 ion channels; however, their involvement in the hearing system is less clear. In this study, the mutations of gap junction proteins beta 2 (GJB2), beta 3 (GJB3) and beta 6 (GJB6) were screened in the white Caucasian population in Hungary using gene mapping and immunofluorescence methods from translated proteins of these genes—connexins on blood cells. Expression of connexins and Kir2.1 ion channels was investigated in the blood cells of deaf patients prior to cochlear implantation, and the results show significantly decreased amounts of connexin26 and connexin43. In addition, the coexpression of Kir2.1 ion channels with synapse-associated 97 proteins was partially impaired. Our investigation revealed a reduced level of Kir2.1 channels in deaf patients indicating a crucial role for the functional Shak...
Journal für Hirnforschung, 1993
The dentate gyrus has been shown to receive a laminated and target selective GABAergic input (Han... more The dentate gyrus has been shown to receive a laminated and target selective GABAergic input (Han et al., 1993; Halasy and Somogyi, 1993), but the numerical parameters of this innervation are not known. In order to establish the relative weight of GABAergic inputs to the dendritic versus somatic regions of granule cells the numerical density and proportion of GABA-immunopositive and immunonegative synaptic boutons and their postsynaptic targets were determined in the molecular and granule cell layers of the dentate gyrus using the postembedding immunogold method. The granule cell layer contained 9% of all synapses with the remaining 91% being in the molecular layer. Altogether 17% of all synaptic boutons were GABA-immunoreactive, and they formed either type 1 or type 2 synaptic junctions. About 88% of synaptic boutons in the granule cell layer and 7-8% in the molecular layer were GABA-positive. However, the numerical density (number of synapses per unit volume) of GABA-immunoreactiv...
Ophiobolins are important members of the family of phytotoxic metabolites, and they possess antit... more Ophiobolins are important members of the family of phytotoxic metabolites, and they possess antitumor, antibacterial, antifungal activities. At the same time, the knowledge on the effect of ophiobolins on ion channels is very limited. The voltage-dependent transient outward currents (Ito) are determined by kv4.2 and kv4.3 ion channels. Increasing evidence points to a role of HMGB1 and synapse-associated protein 97 (Sap97) as underlying factors related to inflammation. The Sap97 associates with kv4.x type channels in the complex and modulating their kinetic properties. Our hypothesis was that Sap97 mainly localizes in the intercalated discs of the cardiac muscle, therefore the altered expression of ion channels is presumably involved in the inhibition of normal mechanical parameters and physiological function of transient outward current (Ito). Our approach was to use purified 6-epi-ophiobolin A as effective molecular tools in the investigation of ion channels on cardiomyocytes. In t...
Pesticide Biochemistry and Physiology, 1994
Aquatic Toxicology, 1995
The in vitro and in vivo effects of the insecticides methidathion (MD) and deltamethrin (DM) on a... more The in vitro and in vivo effects of the insecticides methidathion (MD) and deltamethrin (DM) on acetylcholinesterase (AChE, EC 3.1.1.7) in different tissues were examined in adult carp (Cyprinus carpio L.). The changes in biochemical blood parameters, such as the levels of glutamic-oxaloacetic transaminase (GOT, EC 2.6.1. l), lactate dehydrogenase (LDH, EC 1.1.2.3) and glucose, were also studied in DM-treated fish. The in vitro kinetic results for both insecticides showed that the inhibition of brain AChE was of mixed type, with K,(MD) = 6.0 + 1 .O ,uM and K,(DM) = 15.6 I!I 2.4 ,BM. In vivo treatment with 2 mgll MD for 5 days caused a 70-90% decrease in the AChE activity of different organs, while treatment with 2 pg/l DM for 3 days did not result in such a drastically inhibited AChE. The relative distribution of the AChE molecular forms in the liver of MD-treated carps was significantly different from that in the control animals. The content of the G, form increased, while that of G, decreased. The extents of the differences were much lower in the other tissues investigated for both MD and DM treatments. In vivo DM treatment for 3 days caused a 20% decrease in the AChE activity of the blood serum, while the GOT and LDH activities increased 2.5-fold (72-h sample) and 1.5-fold (6-h sample) as compared with those of the control carp. The blood glucose level was 30%' higher (6-h sample) than that of the control fish. After the fish were returned to clean water, the parameters revealed that the recovery took only 2448 h. The accumulation of MD was highest in the liver and the roe, while the content of the skeletal muscle could not be detected by the methods used. No DM could be detected in any of the tissues, though the sensitivity of the measurement was 0.0005 mg/lOOO g wet tissue. Electronmicroscopy indicated subcellular changes in the hepatocytes. All the observed changes demonstrate the effects of MD and DM on different fish enzymes under laboratory conditions. The changes in AChE indicate how serious the neuronal damage is, while the other parameters relate to the stressed state of the fish.
Acta biologica Hungarica, 1987
Authors studied the fine structural characteristics of the neuromuscular junctions in the aliment... more Authors studied the fine structural characteristics of the neuromuscular junctions in the alimentary tract of phylogenetically different animal species. Nearly in each studied species the so-called close contacts were observable, where the sarcolemma and axolemma establish a junction; the gap of this contact is 10-100 nm wide, and the neurotransmitters can affect the muscles through non-synaptic release (exocytosis). The junctional gap is widest in the gut wall of earthworm: 100-200 nm. Only close contacts are to be found in the alimentary canal of snail, and here, the junctional gap is as narrow as 10-15 nm. Beside close contacts synaptic neuromuscular junctions also occur in the locust gut. Their fine structural organization refer to that of chemical synapses. As in the tench intestine both striated and smooth muscular elements can be found, motor endplates as well as close contacts take part in their innervation. Only close contacts are in the smooth muscular layer of domestic fo...
Histological studies on the marsupium of two terrestrial isopods... 81
Brain Research, Sep 1, 2010
European Journal of Neuroscience
Acta biologica Hungarica, 1987
Authors studied the fine structural characteristics of the neuromuscular junctions in the aliment... more Authors studied the fine structural characteristics of the neuromuscular junctions in the alimentary tract of phylogenetically different animal species. Nearly in each studied species the so-called close contacts were observable, where the sarcolemma and axolemma establish a junction; the gap of this contact is 10-100 nm wide, and the neurotransmitters can affect the muscles through non-synaptic release (exocytosis). The junctional gap is widest in the gut wall of earthworm: 100-200 nm. Only close contacts are to be found in the alimentary canal of snail, and here, the junctional gap is as narrow as 10-15 nm. Beside close contacts synaptic neuromuscular junctions also occur in the locust gut. Their fine structural organization refer to that of chemical synapses. As in the tench intestine both striated and smooth muscular elements can be found, motor endplates as well as close contacts take part in their innervation. Only close contacts are in the smooth muscular layer of domestic fo...