Our own study as well as others have previously reported that hypoxia activates 15-lipoxygenase (15-LO) in the brain, causing a series of chain reactions, which exacerbates ischemic stroke. 15-hydroxyeicosatetraenoic acid (15-HETE) and 15-oxo-eicosatetraenoic acid (15-oxo-ETE/15-KETE) are 15-LO-specific metabolites of arachidonic acid (AA). 15-HETE was found to be rapidly converted into 15-oxo-ETE by 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in some circumstances. We have demonstrated that 15-HETE promotes cerebral vasoconstriction during hypoxia. However, the effect of 15-oxo-ETE upon the contraction of cerebral vasculature remains unclear. To investigate this effect and to clarify the underlying mechanism, we performed immunohistochemistry and Western blot to test the expression of 15-PGDH in rat cerebral tissue, examined internal carotid artery (ICA) tension in isolated rat ICA rings. Western blot and reverse transcription polymerase chain reaction (RT-PCR) were used to analyze the expression of voltage-gated potassium (Kv) channels (Kv2.1, Kv1.5, and Kv1.1) in cultured cerebral arterial smooth muscle cells (CASMCs). The results showed that the levels of 15-PGDH expression were drastically elevated in the cerebral of rats with hypoxia, and 15-oxo-ETE enhanced ICA contraction in a dose-dependent manner. This effect was more significant in the hypoxic rats than in the normoxic rats. We also found that 15-oxo-ETE significantly attenuated the expression of Kv2.1 and Kv1.5, but not Kv1.1. In conclusion, these results suggest that 15-oxo-ETE leads to the contraction of the ICA, especially under hypoxic conditions and that specific Kv channels may play an important role in 15-oxo-ETE-induced ICA constriction.

• MeSH
• 4-aminopyridin MeSH
• arteria carotis interna metabolismus   MeSH
• draslíkové kanály metabolismus   MeSH
• glibenklamid MeSH
• hydroxyprostaglandindehydrogenasy metabolismus   MeSH
• hypoxie metabolismus   MeSH
• kyseliny arachidonové metabolismus   MeSH
• potkani Wistar MeSH
• techniky in vitro MeSH
• tetraethylamonium MeSH
• vazokonstrikce * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 15-hydroxyprostaglandin dehydrogenase MeSH Prohlížeč
• 4-aminopyridin MeSH
• 5-oxo-6,8,11,14-eicosatetraenoic acid MeSH Prohlížeč
• draslíkové kanály MeSH
• glibenklamid MeSH
• hydroxyprostaglandindehydrogenasy MeSH
• kyseliny arachidonové MeSH
• tetraethylamonium MeSH

The mouse Dach1 gene, involved in the development of the neocortex and the hippocampus, is expressed by neural stem cells (NSCs) during early neurogenesis, and its expression also continues in a subpopulation of cells in the dorsal part of the lateral ventricles (LV) of the adult mouse brain. In this study we aimed to elucidate the role of Dach1-expressing cells in adult neurogenesis/gliogenesis under physiological as well as post-ischemic conditions, employing transgenic mice in which the expression of green fluorescent protein (GFP) is controlled by the D6 promotor of the mouse Dach1 gene. A neurosphere-forming assay of GFP⁺ cells isolated from the dorsal part of the LV was carried out with subsequent differentiation in vitro. To elucidate the neurogenic/gliogenic potential of GFP⁺ cells in the dorsal part of the LV, in situ immunohistochemical/electrophysiological analyses of GFP⁺ cells in adult sham-operated brains (controls) and those after middle cerebral artery occlusion (MCAo) were performed. The GFP⁺ cells isolated from the dorsal part of the LV of controls formed neurospheres and differentiated solely into a glial phenotype, while those isolated after MCAo also gave rise to cells with the properties of neuronal precursors. In situ analyses revealed that GFP⁺ cells express the phenotype of adult NSCs or neuroblasts in controls as well as following ischemia. Following MCAo we found a significantly increased number of GFP⁺ cells expressing doublecortin as well as a number of GFP⁺ cells migrating through the rostral migratory stream into the olfactory bulb, where they probably differentiated into calretinin⁺ interneurons. Collectively, our results suggest the involvement of the mouse Dach1 gene in adult neurogenesis; cells expressing this gene exhibit the properties of adult NSCs or neuroblasts and respond to MCAo by enhanced neurogenesis.

• MeSH
• 4-aminopyridin farmakologie   MeSH
• blokátory sodíkových kanálů farmakologie   MeSH
• buněčná diferenciace fyziologie   MeSH
• degenerace nervu etiologie   patologie   MeSH
• dospělé kmenové buňky fyziologie   MeSH
• infarkt arteria cerebri media komplikace   MeSH
• membránové potenciály účinky léků   MeSH
• metoda terčíkového zámku MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši transgenní MeSH
• myši MeSH
• neurogeneze fyziologie   MeSH
• neurony metabolismus   MeSH
• oční proteiny metabolismus   MeSH
• počet buněk MeSH
• proteiny nervové tkáně metabolismus   MeSH
• techniky in vitro MeSH
• tetraethylamonium farmakologie   MeSH
• tetrodotoxin farmakologie   MeSH
• ventriculi laterales patologie   MeSH
• zelené fluorescenční proteiny genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 4-aminopyridin MeSH
• blokátory sodíkových kanálů MeSH
• Dach1 protein, mouse MeSH Prohlížeč
• oční proteiny MeSH
• proteiny nervové tkáně MeSH
• tetraethylamonium MeSH
• tetrodotoxin MeSH
• zelené fluorescenční proteiny MeSH

The activation of Ca(2+)-dependent K(+) channels (BK(Ca)) leads to the attenuation of vascular contraction. Our study aimed to evaluate BK(Ca) influence on norepinephrine (NE)-induced femoral artery contraction in two forms of genetic hypertension. NE dose-response curves were studied before and after BK(Ca) blockade or after combined blockade of BK(Ca) and NO synthase (NOS) in femoral arteries with intact endothelium from normotensive Wistar (WIS), hypertensive hereditary hypertriglyceridemic (HTG), or spontaneously hypertensive rats (SHR). NE-induced contractions of femoral arteries were augmented in both hypertensive strains compared with Wistar rats, but acetylcholine-induced relaxation was impaired in HTG only. The increase of basal vascular tone of isolated arteries after BK(Ca) blockade was similar in all rat strains, but subsequent NOS inhibition increased basal vascular tone more in vessels from both hypertensive rat strains. NOS inhibition increased sensitivity to NE in all strains, but BK(Ca) blockade in SHR only. Neither treatment enhanced maximal NE-induced contraction. NO-dependent attenuation of NE-induced contractions was greater in SHR than HTG or Wistar vessels, whereas large conductance Ca(2+)-dependent K(+) channels may play a greater role in modulating vascular contraction in the severe form of hypertension.

• MeSH
• arteria femoralis účinky léků   patofyziologie   MeSH
• blokátory draslíkových kanálů farmakologie   MeSH
• cévní endotel účinky léků   patofyziologie   MeSH
• hypertenze farmakoterapie   genetika   patofyziologie   MeSH
• inhibitory enzymů farmakologie   MeSH
• krysa rodu Rattus MeSH
• modely nemocí na zvířatech MeSH
• nitroarginin farmakologie   MeSH
• noradrenalin farmakologie   MeSH
• potkani inbrední SHR MeSH
• potkani Wistar MeSH
• synthasa oxidu dusnatého antagonisté a inhibitory   metabolismus   MeSH
• tetraethylamonium farmakologie   MeSH
• vazokonstrikce účinky léků   fyziologie   MeSH
• vazokonstriktory farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• blokátory draslíkových kanálů MeSH
• inhibitory enzymů MeSH
• nitroarginin MeSH
• noradrenalin MeSH
• synthasa oxidu dusnatého MeSH
• tetraethylamonium MeSH
• vazokonstriktory MeSH

The aim of this study was to test the hypothesis that vasorelaxing action of vasonatrin peptide (VNP) is due to activation of the large-conductance Ca(2+)-activated potassium channel (BK(Ca)) via guanylyl cyclase (GC)-coupled natriuretic peptide receptors (NPRs) in vascular smooth muscle cells (VSMCs). Contraction experiments were performed using human radial artery, whereas BK(Ca) current by patch clamp was recorded in cells from rat mesenteric artery. Contractility of rings cut from human radial artery was detected in vitro. As a result, VNP induced a dose-dependent vasorelaxation of human radial artery, which could be mimicked by 8-Br-cGMP, and suppressed by TEA, a blocker of BK(Ca), HS-142-1, a blocker of GC-coupled NPRs, or methylene blue (MB), a selective inhibitor of guanylyl cyclase. Sequentially, whole-cell K(+) currents were recorded using patch clamp techniques. BK(Ca) current of VSMCs isolated from rat mesentery artery was obtained by subtracting the whole cell currents after applications of 10(-7) mol/l iberiotoxin (IBX) from before its applications. In accordance with the results of arterial tension detection, BK(Ca) current was significantly magnified by VNP, which could also be mimicked by 8-Br-cGMP, whereas suppressed by HS-142-1, or MB. Taken together, VNP acts as a potent vasodilator, and NPRA/B-cGMP-BK(Ca) is one possible signaling system involved in VNP induced relaxation.

• MeSH
• arteria radialis cytologie   účinky léků   fyziologie   MeSH
• arteriae mesentericae cytologie   účinky léků   fyziologie   MeSH
• atriální natriuretický faktor farmakologie   fyziologie   MeSH
• guanosinmonofosfát cyklický analogy a deriváty   farmakologie   MeSH
• guanylátcyklasa fyziologie   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• metoda terčíkového zámku MeSH
• peptidy farmakologie   MeSH
• receptory pro atriální natriuretický faktor fyziologie   MeSH
• svaly hladké cévní cytologie   účinky léků   fyziologie   MeSH
• techniky in vitro MeSH
• tetraethylamonium farmakologie   MeSH
• vápníkem aktivované draslíkové kanály s vysokou vodivostí agonisté   fyziologie   MeSH
• vazodilatace účinky léků   fyziologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 8-bromocyclic GMP MeSH Prohlížeč
• atrial natriuretic factor receptor A MeSH Prohlížeč
• atrial natriuretic factor receptor B MeSH Prohlížeč
• atriální natriuretický faktor MeSH
• guanosinmonofosfát cyklický MeSH
• guanylátcyklasa MeSH
• iberiotoxin MeSH Prohlížeč
• peptidy MeSH
• receptory pro atriální natriuretický faktor MeSH
• tetraethylamonium MeSH
• vápníkem aktivované draslíkové kanály s vysokou vodivostí MeSH
• ventricular natriuretic peptide, eel MeSH Prohlížeč

Hypertension due to chronic inhibition of NO synthase (NOS) by Nomega-nitro-L-arginine methyl ester (L-NAME) administration is characterized by both impaired NO-dependent vasodilation and enhanced sympathetic vasoconstriction. The aim of our study was to evaluate changes in the participation of major vasoactive systems in L-NAME-treated rats which were subjected to simultaneous antihypertensive (captopril) or antioxidant (N-acetylcysteine, NAC) treatment. Three-month-old Wistar males treated with L-NAME (60 mg/kg/day) for 5 weeks were compared to rats in which L-NAME treatment was combined with simultaneous chronic administration of captopril or NAC. Basal blood pressure (BP) and its acute responses to consecutive i.v. injections of captopril (10 mg/kg), pentolinium (5 mg/kg), L-NAME (30 mg/kg), tetraethylammonium (TEA, 16 mg/kg) and nitroprusside (NP, 20 microg/kg) were determined in conscious rats at the end of the study. The development of L-NAME hypertension was prevented by captopril treatment, whereas NAC treatment caused only a moderate BP reduction. Captopril treatment normalized the sympathetic BP component and significantly reduced residual BP (measured at full NP-induced vasodilation). In contrast, chronic NAC treatment did not modify the sympathetic BP component or residual BP, but significantly enhanced NO-dependent vasodilation. Neither captopril nor NAC treatment influenced the compensatory increase of TEA-sensitive vasodilation mediated by endothelium-derived hyperpolarizing factor in L-NAME-treated rats. Chronic captopril treatment prevented L-NAME hypertension by lowering of sympathetic tone, whereas chronic NAC treatment attenuated L-NAME hypertension by reduction in the vasodilator deficit due to enhanced NO-dependent vasodilation.

• MeSH
• acetylcystein farmakologie   terapeutické užití   MeSH
• antihypertenziva farmakologie   terapeutické užití   MeSH
• hypertenze chemicky indukované   prevence a kontrola   MeSH
• kaptopril farmakologie   terapeutické užití   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• NG-nitroargininmethylester antagonisté a inhibitory   farmakologie   MeSH
• nitroprusid farmakologie   terapeutické užití   MeSH
• pentoliniumtartrát farmakologie   terapeutické užití   MeSH
• potkani Wistar MeSH
• tetraethylamonium farmakologie   terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylcystein MeSH
• antihypertenziva MeSH
• kaptopril MeSH
• NG-nitroargininmethylester MeSH
• nitroprusid MeSH
• pentoliniumtartrát MeSH
• tetraethylamonium MeSH

The expression patterns of plasma membrane transporters and channels undergo developmental changes during cell differentiation and postnatal development. Until now, little is known about cell membrane conductances during maturation of intestinal crypts even though it is accepted that the crypts undergo dramatic changes during this period of life. Using the whole-cell patch clamp technique, we investigated the developmental changes of potassium conductance (GK) in rat colonic crypts and its heterogeneity along the crypt-surface axis. The resting membrane potential of immature crypts was sensitive to Ba2+ and was higher than in mature crypts. The whole cell conductance during outward currents was higher in immature crypts than in the crypts of adult animals and was reduced by Ba2+ and tetraethylammonium (TEA). With Na+-containing Ringer solution in the bath and K+-containing solution in the pipette, Ba2+- and TEA-sensitive outward currents and conductances were higher in immature than in mature crypts. The TEA-sensitive conductance in immature crypts was distributed heterogenously along the crypt-surface axis with higher values in undifferentiated cells of the crypt base than in differentiated cells of the crypt surface. These data indicate that (1) both colonocyte differentiation and maturation of colonic crypt epithelium are associated with decreasing GK and (2) the axial heterogeneity already exists early in postnatal life when the colonic epithelium undergoes rapid proliferation and growth associated with elongation and bifurcation of the crypts.

• MeSH
• baryum farmakologie   MeSH
• buněčná membrána účinky léků   fyziologie   MeSH
• elektrická vodivost MeSH
• kolon cytologie   účinky léků   růst a vývoj   MeSH
• krysa rodu Rattus MeSH
• metoda terčíkového zámku MeSH
• novorozená zvířata MeSH
• stárnutí fyziologie   MeSH
• tetraethylamonium farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• baryum MeSH
• tetraethylamonium MeSH

The effects of Sr2+ on contraction and action potential were studied in rabbit papillary muscles and compared with effects of tetraethylammonium (TEA+). The membrane potential was measured with KCl-filled microelectrodes and the contraction was simultaneously recorded using a mechanoelectrical transducer. A partial (90%) substitution of extracellular Ca2+ (Ca2+e) by Sr2+ produced stimulation frequency-dependent prolongation of the action potential (AP) with a dominant phase "plateau" as well as prolongation of the contraction. At low frequencies where the AP prolongation was well pronounced, the contraction became biphasic. The effect of Sr2+ on both AP and contraction was blocked by nifedipine (10 mumol/l) or by increasing Ca2+e. Ryanodine suppressed the early contraction component only. AP was prolonged to a similar extent and in the same frequency-dependent manner by TEA+ (20 mmol/l). Despite similar AP configuration, no biphasic contraction developed in the presence of TEA+. High Ca2+e (10 mmol/l) or low Na+e (70 mmol/l) suppressed the TEA+ effect on AP. The data indicate that the two components of the biphasic contraction are of different origin; the early one is activated by activator cation released from the sarcoplasmic reticulum while the late one results from the Sr2+ entry across the sarcolemma via L-type Ca2+ channels.

• MeSH
• akční potenciály fyziologie   MeSH
• elektrofyziologie MeSH
• ionty * MeSH
• králíci MeSH
• myokard metabolismus   MeSH
• papilární svaly metabolismus   MeSH
• pumpa pro výměnu sodíku a vápníku metabolismus   MeSH
• stroncium farmakologie   MeSH
• svalová kontrakce fyziologie   MeSH
• tetraethylamonium farmakologie   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• ionty * MeSH
• pumpa pro výměnu sodíku a vápníku MeSH
• stroncium MeSH
• tetraethylamonium MeSH

Changes in the ability of substances to diffuse in the intersticial space of the brain are important factors in the pathophysiology of cerebrovascular diseases. Extracellular space (ECS) volume fraction alpha (alpha = ECS volume/ total tissue volume), tortuosity lambda (lambda 2 = free diffusion coefficient/apparent diffusion coefficient), and nonspecific uptake (k')-three diffusion parameters of brain tissue were studied in cortex and subcortical white matter (WM) of the developing rat during anoxia. Changes were compared with the rise in extracellular potassium concentration ([K+]e), extracellular pH (pHe) shifts, and anoxic depolarization (AD). Diffusion parameters were determined from extracellular concentration-time profiles of tetramethylammonium (TMA+) or tetraethylammonium (TEA+), TMA+, TEA+, K+, and pH changes were measured using ion-selective microelectrodes. In the cortex and WM of animals at 4-12 postnatal days (P4-P12), the volume fraction, alpha, is larger than that of animals at > or = P21. Anoxia evoked by cardiac arrest brought about a typical rise in [K+]e to approximately 60-70 mM, AD of 25-30 mV, decrease in alpha, increase in lambda, and increase in k'. At P4-P6, alpha decreased from approximately 0.43 to 0.05 in cortical layer V and from approximately 0.45 to 0.5 in WM. Tortuosity, lambda, increased in the cortex from 1.50 to 2.12 and in WM from approximately 1.48 to 2.08. At P10-P12 and at P21-P23, when alpha in normoxic rats is lower than at P4-P6 by approximately 25 and 50%, respectively, the final changes in values of alpha and lambda evoked by anoxia were not significantly different from those in P4-P6. However, the younger the animal, the longer the time course of the changes. On P4-P6 final changes in alpha, lambda and k' in cortex and WM were reached after 37 +/- 3 min and 54 +/- 2 min; on P10-P12, after 24 +/- 2 and 27 +/- 3 min; and on P21-P23 at 15 +/- 1 and 17 +/- 3 min, respectively (mean +/- SE, n = 6). The time course of the changes was longer in WM than in gray matter (GM), particularly during the first postnatal week, i.e., in the period during which WM is largely unmyelinated. Changes in diffusion parameters occurred in three phases. The first slow and second fast changes occurred simultaneously with the rise in [K+]e and AD. Peaks in [K+]e and AD were reached simultaneously; the younger the animal, the longer the time course of the changes. The third phase outlasted the rise in [K+]e and AD by 10-15 min and correlated with the acid shift in pHe. Linear regression analysis revealed a positive correlation between the normoxic size of the ECS volume and the time course of the changes. Slower changes in ECS volume fraction and tortuosity in nervous tissue during development can contribute to slower impairment of signal transmission, e.g., due to lower accumulation of ions and neuroactive substances released from cells and their better diffusion from the hypoxic area in uncompacted ECS.

• MeSH
• corpus callosum růst a vývoj   metabolismus   patologie   MeSH
• difuze MeSH
• draslík metabolismus   MeSH
• extracelulární prostor metabolismus   MeSH
• ischemie mozku komplikace   metabolismus   patologie   MeSH
• koncentrace vodíkových iontů MeSH
• krysa rodu Rattus MeSH
• kvartérní amoniové sloučeniny farmakokinetika   MeSH
• mozková hypoxie etiologie   metabolismus   MeSH
• mozková kůra růst a vývoj   metabolismus   patologie   MeSH
• neuroglie metabolismus   patologie   MeSH
• neurony metabolismus   patologie   MeSH
• potkani Wistar MeSH
• tetraethylamoniové sloučeniny farmakokinetika   MeSH
• tetraethylamonium MeSH
• velikost buňky MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• draslík MeSH
• kvartérní amoniové sloučeniny MeSH
• tetraethylamoniové sloučeniny MeSH
• tetraethylamonium MeSH
• tetramethylammonium MeSH Prohlížeč

Extracellular space (ECS) volume fraction (alpha), ECS tortuosity (lambda), and nonspecific uptake (k'), three parameters affecting the diffusion of substances in nervous tissue, were studied during ischemia and anoxia in the rat spinal cord gray matter in vivo. Progressive ischemia evoked by exsanguination, as well as anoxia evoked by respiratory or cardiac arrest, produced prominent extracellular K+ and pH changes closely related to a decrease in blood pressure and amplitude of field potentials. With use of ion-selective microelectrodes, the changes in the diffusion parameters were measured by quantitative analysis of concentration-time profiles of tetramethylammonium (TMA+) applied by iontophoresis concomitantly with ionic shifts. Under normoxic conditions (in rats with blood pressure of 80-110 mm Hg) diffusion parameters in the dorsal horn gray matter at depth 500-900 microns were as follows: alpha = 0.20 +/- 0.019, lambda = 1.62 +/- 0.12, k' = 4.6 +/- 2.5 x 10(-3) s-1 (mean +/- SD, n = 39). Extracellular K+, pH, and diffusion properties gradually changed during progressive ischemia. As the blood pressure fell to 50-60 mm Hg and field potential amplitude to 20-60%, K+ rose to 6-12 mM, pHe fell by approximately 0.05-0.1 pH unit, and volume fraction of the ECS significantly decreased, to alpha = 0.16 +/- 0.019 (n = 22). Even though the tortuosity remained virtually constant, the nonspecific uptake significantly decreased to k' = 3.4 +/- 1.8 x 10(-3) s-1. As the blood pressure fell to 20-30 mm Hg and field potential amplitude to 0-6%, K+ rose to 60-70 mM, pHe fell by approximately 0.6-0.8 pH unit, and all three diffusion parameters significantly changed. The ECS volume fraction decreased to alpha = 0.05 +/- 0.021, tortuosity increased to lambda = 2.00 +/- 0.24, and TMA+ uptake decreased to k' = 1.5 +/- 1.6 x 10(-3) s-1 (n = 12). No further increase in extracellular K+ or changes in the alpha were found during and up to 120 min after the death of the animal. However, there was a further significant increase in lambda = 2.20 +/- 0.14 and decrease in k' = 0.4 +/- 0.3 x 10(-3) s-1 (n = 24). The acid shift reached its maximum level at approximately 5-10 min after respiratory arrest and then the pHe gradually increased by approximately 0.2 unit. Full recovery to "normoxic" diffusion parameters was achieved after reinjection of the blood or after an injection of noradrenaline during severe ischemia, if this resulted in a rise in blood pressure above 80 mm Hg and a decrease in extracellular K+ below 12 mM.(ABSTRACT TRUNCATED AT 400 WORDS)

• MeSH
• difuze MeSH
• draslík metabolismus   MeSH
• extracelulární prostor metabolismus   MeSH
• hypoxie metabolismus   MeSH
• ischemie metabolismus   MeSH
• krysa rodu Rattus MeSH
• mícha krevní zásobení   metabolismus   MeSH
• potkani Wistar MeSH
• referenční hodnoty MeSH
• tetraethylamoniové sloučeniny farmakokinetika   MeSH
• tetraethylamonium MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• draslík MeSH
• tetraethylamoniové sloučeniny MeSH
• tetraethylamonium MeSH

After 3-7 days in culture, chicken myotubes possess five types of K+ channel: two high-conductance channels of 195 and 105 pS which are sensitive to tetraethylammonium (TEA), an ATP-sensitive channel of 64 pS and two low-conductance channels of 40 and 15 pS which are insensitive to TEA and ATP. The same population of channels is to be found in EGTA-treated muscle cells with blocked fusion and, with the exception of the ATP-sensitive channel, also in 1-day-old myoblasts. There are differences between myoblasts and myotubes in the percentage of incidence of individual channel types. High-conductance K+ channels are most frequently to be observed in myotubes, but they are rare in myoblasts and EGTA-treated cells where low-conductance K+ channels predominate.

• MeSH
• adenosintrifosfát farmakologie   MeSH
• buněčná membrána fyziologie   MeSH
• draslíkové kanály účinky léků   fyziologie   MeSH
• EGTA farmakologie   MeSH
• elektrická vodivost MeSH
• elektrofyziologie přístrojové vybavení   metody   MeSH
• kultivované buňky MeSH
• kuřecí embryo MeSH
• membránové potenciály MeSH
• svaly fyziologie   MeSH
• tetraethylamoniové sloučeniny farmakologie   MeSH
• tetraethylamonium MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenosintrifosfát MeSH
• draslíkové kanály MeSH
• EGTA MeSH
• tetraethylamoniové sloučeniny MeSH
• tetraethylamonium MeSH