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PubMed2001

Distribution analysis of human two pore domain potassium channels in tissues of the central nervous system and periphery.

Potassium channels are amongst the most heterogeneous class of ion channels known and are responsible for mediating a diverse range of biological functions. The most recently described family of K+ channels, the 'two pore-domain family', contain four membrane spanning domains and two pore-forming domains, suggesting that two channel subunits associate to form a functional K+ pore. Several sub-families of the two pore domain potassium channel family have been described, including the weakly inward rectifying K+ channel (TWIK), the acid-sensitive K+ channel (TASK), the TWIK-related K+ channel (TREK) and the TWIK-related arachidonic acid stimulated K+ channel (TRAAK). However, comparison of the mRNA expression of these channels has been difficult due to the differences in methods used and the species studied. In the present study, we used a single technique, TaqMan semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), to investigate the mRNA distribution of all currently known two pore potassium channels in human central nervous system (CNS) and peripheral tissues. TWIK-1 and the TWIK-1-like channel KCNK7 were predominantly expressed in the CNS, in contrast to TWIK-2 which was preferentially expressed in peripheral tissues such as pancreas, stomach, spleen and uterus. TASK-1 was expressed in the CNS and some peripheral tissues, whereas TASK-2 was exclusively expressed in the periphery except for mRNA expression observed in dorsal root ganglion and spinal cord. In addition, mRNA expression of the recently identified TASK-3, was almost completely exclusive to cerebellum with little or no mRNA detected in any other tissues. TREK-1 and TRAAK mRNA expression was predominantly CNS specific in contrast to the closely related TREK-2, which was expressed in both CNS and peripheral tissues. Studying the mRNA expression profiles of known two pore domain K+ channels will aid in the understanding of the biological roles of these channels. Furthermore, identification of common areas of expression may help identify which channels, if any, associate to form heteromeric K+ channel complexes.

Central Nervous System↗
PubMed1988

Pandinus imperator scorpion venom blocks voltage-gated potassium channels in GH3 cells.

We examined the effects of Pandinus imperator scorpion venom on voltage-gated potassium channels in cultured clonal rat anterior pituitary cells (GH3 cells) using the gigohm-seal voltage-clamp method in the whole-cell configuration. We found that Pandinus venom blocks the voltage-gated potassium channels of GH3 cells in a voltage-dependent and dose-dependent manner. Crude venom in concentrations of 50-500 micrograms/ml produced 50-70% block of potassium currents measured at -20 mV, compared with 25-60% block measured at +50 mV. The venom both decreased the peak potassium current and shifted the voltage dependence of potassium current activation to more positive potentials. Pandinus venom affected potassium channel kinetics by slowing channel opening, speeding deactivation slightly, and increasing inactivation rates. Potassium currents in cells exposed to Pandinus venom did not recover control amplitudes or kinetics even after 20-40 min of washing with venom-free solution. The concentration dependence of crude venom block indicates that the toxins it contains are effective in the nanomolar range of concentrations. The effects of Pandinus venom were mimicked by zinc at concentrations less than or equal to 0.2 mM. Block of potassium current by zinc was voltage dependent and resembled Pandinus venom block, except that block by zinc was rapidly reversible. Since zinc is found in crude Pandinus venom, it could be important in the interaction of the venom with the potassium channel. We conclude that Pandinus venom contains toxins that bind tightly to voltage-dependent potassium channels in GH3 cells. Because of its high affinity for voltage-gated potassium channels and its irreversibility, Pandinus venom may be useful in the isolation, mapping, and characterization of voltage-gated potassium channels.

Animals↗
PubMed2000

Selective mitochondrial adenosine triphosphate-sensitive potassium channel activation is sufficient to precondition human myocardium.

OBJECTIVES: Recently, the mitochondrial adenosine triphosphate-sensitive potassium channel has been suggested to be the final common effector of myocardial preconditioning. The purpose of this study is to determine whether selective mitochondrial adenosine triphosphate-sensitive potassium channel activation alone can precondition human myocardium from an ischemia/reperfusion insult. METHODS: Isolated human right atrial trabeculae were placed in tissue baths, paced, and subjected to 30 minutes of normothermic hypoxia (ischemia) followed by 45 minutes of reoxygenation (reperfusion). Trabeculae were preconditioned with a selective mitochondrial adenosine triphosphate-sensitive potassium channel opener (diazoxide 30 micromol/L) or a nonselective purinergic agonist, adenosine (125 micromol/L), for 5 minutes (adenosine) followed by a 10-minute washout period. Developed force at end reperfusion (mean +/- standard error) was compared with baseline, and tissue creatine kinase and adenosine triphosphate levels were measured after ischemia/reperfusion. RESULTS: Trabeculae subjected to ischemia/reperfusion exhibited 30% +/- 2% of baseline developed force, whereas trabeculae subjected to selective adenosine triphosphate-sensitive potassium channel opening (diazoxide) and nonselective purinergic agonist (adenosine) recovered to 55% +/- 7% and 46% +/- 3% of baseline developed force, respectively. Tissue creatine kinase activity was preserved in both the diazoxide- and adenosine-treated trabeculae (5.4 +/- 12 and 5.4 +/- 14 micromol/L per gram wet tissue) compared with ischemia/reperfusion (1.8 +/- 0.2 U/mg wet tissue). Adenosine triphosphate levels at end reperfusion were also increased in the trabeculae treated with selective (diazoxide) and nonselective (adenosine) adenosine triphosphate-sensitive potassium channel opener (4.1 +/- 0.01 and 4. 4 +/- 0.2 micromol/L per gram wet tissue) compared with trabeculae subjected to ischemia/reperfusion (1.5 +/- 0.1 micromol/L per gram wet tissue). CONCLUSIONS: These results suggest that selective mitochondrial adenosine triphosphate-sensitive potassium channel activation preconditions human myocardium and the protection conferred is equal to that of adenosine preconditioning. Targeted openers of mitochondrial adenosine triphosphate- sensitive potassium channels promote constructive protection of myocellular energy levels, contractile function, and cellular viability in human myocardium after ischemia/reperfusion.

Adenosine↗
PubMed1998

A hyperprostaglandin E syndrome mutation in Kir1.1 (renal outer medullary potassium) channels reveals a crucial residue for channel function in Kir1.3 channels.

Loss of function mutations in kidney Kir1.1 (renal outer medullary potassium channel, KCNJ1) inwardly rectifying potassium channels can be found in patients suffering from hyperprostaglandin E syndrome (HPS), the antenatal form of Bartter syndrome. A novel mutation found in a sporadic case substitutes an asparagine by a positively charged lysine residue at amino acid position 124 in the extracellular M1-H5 linker region. When heterologously expressed in Xenopus oocytes and mammalian cells, current amplitudes from mutant Kir1.1a[N124K] channels were reduced by a factor of approximately 12 as compared with wild type. A lysine at the equivalent position is present in only one of the known Kir subunits, the newly identified Kir1.3, which is also poorly expressed in the recombinant system. When the lysine residue in guinea pig Kir1.3 (gpKir1.3) isolated from a genomic library was changed to an asparagine (reverse HPS mutation), mutant channels yielded macroscopic currents with amplitudes increased 6-fold. From single channel analysis it became apparent that the decrease in mutant Kir1.1 channels and the increase in mutant gpKir1.3 macroscopic currents were mainly due to the number of expressed functional channels. Coexpression experiments revealed a dominant-negative effect of Kir1.1a[N124K] and gpKir1.3 on macroscopic current amplitudes when coexpressed with wild type Kir1.1a and gpKir[K110N], respectively. Thus we postulate that in Kir1.3 channels the extracellular positively charged lysine is of crucial functional importance. The HPS phenotype in man can be explained by the lower expression of functional channels by the Kir1. 1a[N124K] mutant.

Amino Acid Sequence↗
PubMed1995

[ATP-sensitive potassium channel and hormone/neuropeptide].

ATP-sensitive potassium channels (KATP) are the ion channels which are closely associated with cellular metabolism. A number of chemical compounds which block KATP facilitate the release of hormones or neuropeptides. For example, KATP-blocking agents such as antidiabetic sulfonylureas and imidazolines stimulate insulin secretion from pancreatic beta-cells by decreasing KATP activity. On the other hand, so-called potassium channel openers, KATP-activating drugs which constitute a chemically diverse group of compounds, inhibit growth hormone secretion from anterior pituitary cells and release of gamma-aminobutylic acid from substantia nigra. Several endogenous substances also modulate release of hormone or neuropeptide by affecting KATP activity. Acetylcholine and histamine stimulate the release of endothelium-derived hyperpolarizing factor, which activates KATP in the plasma membrane of vascular smooth muscle cells. Both galanin and somatostatin inhibit insulin release from pancreatic beta-cells by opening KATP through the activation of G-protein. Glucagon-like peptide-1[7-36], which stimulates insulin secretion by indirectly blocking KATP in beta-cells, shows antidiabetic effects in patients with non-insulin-dependent diabetes mellitus. Endosulphine, an endogenous inhibitor of KATP, stimulates insulin secretion from pancreatic beta-cells. Accumulating knowledge of the modulation and function of KATP would help our understanding of the regulation and physiological role of hormones and neuropeptides.

Adenosine Triphosphate↗
PubMed2000

Gene structures and expression profiles of three human KCND (Kv4) potassium channels mediating A-type currents I(TO) and I(SA).

The four known members of the KCND/Kv4 channel family encode voltage-gated potassium channels. Recent studies provide evidence that members of the Kv4 channel family are responsible for native, rapidly inactivating (A-type) currents described in heart (I(TO)) and neurons (I(SA)). In this study, we cloned the human KCND1 cDNA, localized the KCND1 gene to chromosome Xp11.23-p11.3, and determined the genomic structure and tissue-specific expression of the KCND1, KCND2, and KCND3 genes, respectively. The open reading frame of Kv4. 1 is 1941 nucleotides long, predicting a protein of 647 amino acids. The deduced protein sequence of Kv4.1 shows an overall identity of 60% with Kv4.2 and Kv4.3L and corresponds to the common structure of voltage-gated potassium channels. KCND1-specific transcripts were detectable in human brain, heart, liver, kidney, thyroid gland, and pancreas, as revealed by Northern blot and RT-PCR experiments. The comparison of the expression patterns of the known Kv4 family members shows subtype specificity with significant overlaps. The KCND gene structures exhibit an evolutionarily conserved exon pattern with a large first exon containing the intracellular N-terminus and the putative membrane-spanning regions S1 to S5, as well as part of the pore region. The KCND3 gene contains an additional exon of 57 bp, which is not present in the other two KCND genes and gives rise to the C-terminal splice KCND3L variant with an insertion of 19 amino acids.

Chromosome Mapping↗
PubMed2002

Identification of a new class of inhibitors of the voltage-gated potassium channel, Kv1.3, with immunosuppressant properties.

The voltage-gated potassium channel, K(v)1.3, is a novel target for development of immunosuppressants. Using a functional (86)Rb(+) efflux assay, a new class of high-affinity K(v)1.3 inhibitors has been identified. The initial active in this series, 4-phenyl-4-[3-(2-methoxyphenyl)-3-oxo-2-azaprop-1-yl]cyclohexanone (PAC), which is representative of a disubstituted cyclohexyl (DSC) template, displays a K(i) of ca. 300 nM and a Hill coefficient near 2 in the flux assay and in voltage clamp recordings of K(v)1.3 channels in human T-lymphocytes. PAC displays excellent specificity as it only blocks members of the K(v)1 family of potassium channels but does not affect many other types of ion channels, receptors, or enzyme systems. Block of K(v)1.3 by DSC analogues occurs with a well-defined structure-activity relationship. Substitution at the C-1 ketone of PAC generates trans (down) and cis (up) isomer pairs. Whereas many DSC derivatives do not display selectivity in their interaction with different K(v)1.x channels, trans DSC derivatives distinguish between K(v)1.x channels based on their rates of C-type inactivation. DSC analogues reversibly inhibit the Ca(2+)-dependent pathway of T cell activation in in vitro assays. Together, these data suggest that DSC derivatives represent a new class of immunosuppressant agents and that specific interactions of trans DSC analogues with channel conformations related to C-type inactivation may permit development of selective K(v)1.3 channel inhibitors useful for the safe treatment of autoimmune diseases.

Alanine↗
PubMed1997

Carboxy-terminal domain mediates assembly of the voltage-gated rat ether-à-go-go potassium channel.

The specific assembly of subunits to oligomers is an important prerequisite for producing functional potassium channels. We have studied the assembly of voltage-gated rat ether-à-go-go (r-eag) potassium channels with two complementary assays. In protein overlay binding experiments it was shown that a 41-amino-acid domain, close to the r-eag subunit carboxy-terminus, is important for r-eag subunit interaction. In an in vitro expression system it was demonstrated that r-eag subunits lacking this assembly domain cannot form functional potassium channels. Also, a approximately 10-fold molar excess of the r-eag carboxy-terminus inhibited in co-expression experiments the formation of functional r-eag channels. When the r-eag carboxy-terminal assembly domain had been mutated, the dominant-negative effect of the r-eag carboxy-terminus on r-eag channel expression was abolished. The results demonstrate that a carboxy-terminal assembly domain is essential for functional r-eag potassium channel expression, in contrast to the one of Shaker-related potassium channels, which is directed by an amino-terminal assembly domain.

Amino Acid Sequence↗
PubMed1994

Potassium channel inhibitors attenuate neuromodulatory effects of atrial natriuretic factor in the rabbit isolated vas deferens.

This study tested the hypothesis that neuromodulatory effects of atrial natriuretic factor (ANF) are mediated by an activation of potassium channels in the rabbit isolated vas deferens. The neuromodulatory effects of ANF were tested in the presence of the potassium channel inhibitors, tetraethylammonium, 4-aminopyridine, glibenclamide and charybdotoxin. The effects of the first three were ascertained by their prevention of neuromodulatory effects of a cromokalim enantiomer (BRL 38227), which opens ATP-sensitive potassium channels. The nonspecific potassium channel inhibitors, tetraethylammonium (2 mM) and 4-aminopyridine (2 mM) blocked inhibitory effects of both ANF and BRL 38227 on the electrically-induced adrenergic contraction in the rabbit vas deferens. Glibenclamide (10 microM), an inhibitor of ATP-sensitive potassium channels, failed to antagonize ANF effects, but blocked the actions of BRL 38227. Charybdotoxin (100 nM) is known to block large conductance calcium-activated potassium channels, and it attenuated the neuromodulatory effects of ANF; however, the effects of BRL 38227 were sustained in the presence of charybdotoxin. These results are consistent with the hypothesis that the neuromodulatory action of ANF is mediated by the activation of potassium conductances. The potassium channel involved is not an ATP-sensitive channel, because glibenclamide failed to alter the neuromodulatory activity of ANF. We hypothesize that ANF effects could be mediated by an activation of either calcium-activated or outward rectifying potassium channels.

4-Aminopyridine↗
PubMed1989

Enhancement of potassium-sensitive current in heart cells by pinacidil. Evidence for modulation of the ATP-sensitive potassium channel.

Pinacidil belongs to a novel group of compounds that enhance the potassium permeability of vascular smooth muscle. Evidence also exists that this drug enhances the potassium permeability of cardiac tissue. The purpose of the present investigation was to determine if pinacidil alters potassium-channel activity in heart and, if so, which potassium channel is the target. We used the whole-cell arrangement of the patch voltage clamp to record membrane currents from isolated guinea pig ventricular cells. In solutions designed to isolate potassium currents, pinacidil enhances a time-independent current positive to the potassium equilibrium potential. Current measured at voltages negative to the potassium equilibrium potential are essentially unaltered by the drug. The potassium sensitivity of outward current indicates that the target for the drug is a potassium channel. Experiments designed to test for voltage-dependent channel gating strongly suggest that the pinacidil-sensitive current is not voltage gated. Pinacidil-sensitive current is blocked by externally applied Ba2+, Cs+, and tetraethylammonium ion. In addition, it is potently blocked after external application of 100 nM glibenclamide. Taken along with the time- and voltage-independent properties of pinacidil-sensitive current, this pharmacology strongly suggests that the target for pinacidil in heart is the ATP-sensitive potassium channel.

Adenosine Triphosphate↗
PubMed2002

Protection of potassium channel inhibitors against hypoxia/reoxygenation-induced death of cultured hippocampal neurons.

OBJECTIVE: To investigate the effects of potassium channel inhibitors on hypoxia/reoxygenation-induced death of cultured hippocampal neurons. METHODS: Cultured 8 d in vitro, hippocampal neurons were exposed to hypoxia (in mixture of 95% N2 and 5% CO2) for 6 h, and then reoxygenated till the 72nd hour. Different potassium channel inhibitors were applied to the culture solution separately after reoxygenation. Neuron death was analyzed with cell counting and MTT assay. RESULTS: Hypoxia/reoxygenation procedure induced a delayed death of cultured hippocampal neurons. Application of tetraethylammonium (TEA) offered concentration-dependent protection of the neurons against death. Selective high-conductance calcium-activated potassium channel (BK) inhibitor iberiotoxin (IbTX) showed significant neuron protection (P<0.001). However, A-type potassium channel inhibitor 4-aminopyridine presented no protection against neuron death (P>0.05). CONCLUSION: Following hypoxia/reoxygenation, enhanced activity of potassium channel, especially BK channel, may induce neuron death.

4-Aminopyridine↗
PubMed2003

Calnexin co-expression and the use of weaker promoters increase the expression of correctly assembled Shaker potassium channel in insect cells.

Voltage-gated potassium channels control the membrane potential of excitable cells. To understand their function, knowledge of their structure is essential. However, these channels are scarce in natural sources, and overexpression is necessary to generate material for structural studies. We have compared functional expression of the Drosophila Shaker H4 potassium channel in stable insect cell lines and in baculovirus-infected insect cells, using three different baculovirus promoters. Stable insect cell lines expressed correctly assembled channel, which was glycosylated and found predominantly at, or close to, the cell surface. In comparison, the majority of baculovirus-overexpressed Shaker was intracellular and incorrectly assembled. The proportion of functional Shaker increased, however, if the weaker basic protein promoter was used rather than the stronger p10 or polyhedrin promoters. In addition, co-expression of the molecular chaperone, calnexin, increased the quantity of correctly assembled channel protein, suggesting that calnexin can be used to increase the efficiency of channel expression in insect cells.

Animals↗
PubMed1994

Recombinant G-protein beta gamma-subunits activate the muscarinic-gated atrial potassium channel.

Acetylcholine activates inwardly rectifying potassium channels (IK.ACh) in the heart through muscarinic receptor binding and activation of pertussis-toxin-sensitive G proteins. Experiments showing that only the beta gamma-subunit (G beta gamma) activates IK.ACh (ref. 4) were challenged by reports that only the activated alpha-subunit (G alpha) was effective. Here we examine IK.ACh regulation using purified brain and recombinant G-protein subunits. Six recombinant G beta gamma-subunits activated IK.ACh with apparent half-maximal activation concentrations of 3-30 nM. Activation of IK.ACh by recombinant G alpha-GTP gamma S was observed, but this was probably due to release of GTP gamma S from the protein. Importantly, IK.ACh activity elicited by GTP gamma S was inhibited by purified brain and recombinant G alpha-GDP, suggesting that native G beta gamma plays a major role in this pathway. We conclude that G beta gamma is a primary regulator of IK.ACh activity.

Acetylcholine↗
PubMedDate not supplied

[Potassium channels and the development of new drugs].

Ion channel modulation has recently become an attractive target for experimental and clinical research in a never-ending quest for drug development. Following the decades of domination of calcium channel blockers, currently the focus is on potassium channels and their modulators; this is one of the most rapidly developing fields of research. Because potassium channels have an important role in maintaining the membrane potential in all tissues and in shaping the action potential in the heart, potassium channel modulators are expected to provide better therapies primarily in cardiology (acute coronary syndromes, arrhythmias) but also in other branches of medicine.

Animals↗
PubMed2004

Molecular cloning and partial functional characterization of Tsha3--a novel modulatory potassium channel alpha-subunit of trout CNS.

A novel Shaker-related potassium channel subunit termed Tsha3 that is widely expressed in the CNS of trout was PCR-cloned and sequenced: its deduced amino acid sequence showed an extended N-terminal domain with a high proportion of negatively charged residues and possessed highest similarity with KCNA10, a human epithelial potassium channel. Upon heterologous expression in Sf21 cells, homomeric Tsha3 did not yield voltage-activated potassium channels but produced only ohmic currents that reversed at -15 mV. After co-expression with Tsha1, a novel outward rectifier current was generated that differed from homomeric Tsha1 by its slower kinetics of activation, its partial current inactivation, and its partial blockade by 5 mM TEA as well as 1 microM DTX. Co-immunoprecipitation studies using anti-Tsha3 antibodies confirmed that Tsha3 tightly bound with Tsha1 in co-infected Sf21 cells. As revealed from GFP- and DsRed-labeling studies, the pattern of distribution of Tsha1 was profoundly altered after co-infection with Tsha3 subunits.

Animals↗
PubMed2001

Alterations in potassium channel gene expression in atria of patients with persistent and paroxysmal atrial fibrillation: differential regulation of protein and mRNA levels for K+ channels.

OBJECTIVES: Our purpose was to determine whether patients with persistent atrial fibrillation (AF) and patients with paroxysmal AF show alterations in potassium channel expression. BACKGROUND: Persistent AF is associated with a sustained shortening of the atrial action potential duration and atrial refractory period. Underlying molecular changes have not been studied in humans. We investigated whether a changed gene expression of specific potassium channels is associated with these changes in patients with persistent AF and in patients with paroxysmal AF. METHODS: Right atrial appendages were obtained from 8 patients with paroxysmal AF, 10 with persistent AF and 18 matched controls in sinus rhythm. All controls underwent coronary artery bypass surgery, whereas most AF patients underwent Cox's MAZE surgery (atrial arrhythmia surgery to cure AF) (n = 12). All patients had normal left ventricular function. mRNA (ribonucleic acid) levels were measured by semiquantitative polymerase chain reaction and protein content by Western blotting. RESULTS: mRNA levels of transient outward channel (Kv4.3), acetylcholine-dependent potassium channel (Kir3.4) and ATP-dependent potassium channel (Kir6.2) were reduced in patients with persistent AF (-35%, -47% and -36%, respectively, p < 0.05), whereas only Kv4.3 mRNA level was reduced in patients with paroxysmal AF (-29%, p = 0.03). No changes were found for Kv1.5 and HERG mRNA levels in either group. Protein levels of Kv4.3, Kv1.5 and Kir3.1 were reduced both in patients with persistent AF (-39%, -84% and -47%, respectively, p < 0.05) and in those with paroxysmal AF (-57%, -64%, and -40%, respectively, p < 0.05). CONCLUSIONS: Persistent AF is accompanied by reductions in mRNA and protein levels of several potassium channels. In patients with paroxysmal AF these reductions were observed predominantly at the protein level and not at the mRNA level, suggesting a post-transcriptional regulation.

Aged↗
PubMed1990

A family of three mouse potassium channel genes with intronless coding regions.

To understand the molecular mechanisms responsible for generating physiologically diverse potassium channels in mammalian cells, mouse genomic clones have been isolated with a potassium channel complementary DNA, MBK1, that is homologous to the Drosophila potassium channel gene, Shaker. A family of three closely related potassium channel genes (MK1, MK2, and MK3) that are encoded at distinct genomic loci has been isolated. Sequence analysis reveals that the coding region of each of these three genes exists as a single uninterrupted exon in the mouse genome. This organization precludes the generation of multiple forms of the protein by alternative RNA splicing, a mechanism known to characterize the Drosophila potassium channel genes Shaker and Shab. Thus, mammals may use a different strategy for generating diverse K+ channels by encoding related genes at multiple distinct genomic loci, each of which produces only a single protein.

Amino Acid Sequence↗
PubMed1993

Potassium channels in hypokalaemic periodic paralysis: a key to the pathogenesis?

1. A possible role for the ATP-sensitive potassium channels in the pathogenesis of hypokalaemic periodic paralysis was investigated. 2. We assessed insulin release and muscle strength after intravenous glucose loading with and without the potassium channel opener pinacidil and the potassium channel blocker glibenclamide in three patients with hypokalaemic periodic paralysis and in a pair of matched control subjects for each patient. 3. A significantly higher initial insulin response (1.5-30 min) was found in the patients with hypokalaemic periodic paralysis in comparison with the control subjects. During potassium channel blocking with glibenclamide the insulin release was more enhanced in patients than in control subjects. On the other hand, the potassium channel opener pinacidil impaired the insulin release in healthy control subjects but not in patients. The serum glucose levels showed no differences between patients and control subjects. In one of the patients with hypokalaemic periodic paralysis glucose loading resulted in a fall in muscle strength, which did not occur during the administration of pinacidil. 4. These findings suggest a disturbance in the ATP-sensitive potassium channel in patients with hypokalaemic periodic paralysis, which is not limited to pancreatic beta cells, but may be also involved in the abnormal behaviour of skeletal muscle.

Adult↗