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32652. Vasoactive intestinal polypeptide in rat heart atria: the effect of hyperthyroidism
- Creator:
- Jitka Kuncová and Jana Slavíková
- Format:
- print, bez média, and svazek
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, srdce, heart, vasoactive intestinal polypeptide, hyperthyroidism, rat, development, 14, and 612
- Language:
- English
- Description:
- The effects of transient and sustained hyperthyroidism on vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) levels were studied in the heart atria of developing and adult rats. Newborn rats were divided into 5 groups. Neo-T animals were treated with thyroxine (T4) during postnatal days 1-8 and sacrificed at the age of 60 days. Neo-S rats were treated with T4 during postnatal days 1-60 and sacrificed one day later. Adult-1 and Adult-2 animals received T4 during days 52-60 and were sacrificed 5-6 days and 1 day later, respectively. Control animals were injected with saline. VIP-LI concentrations were determined in extracts from the left and right atria separately. In Neo-S and Adult-2 rats, spontaneous heart rate, the weight of both atria and total T4 serum levels were significantly enhanced, while their body weight was decreased. The ratio atria weight to body weight was significantly increased in all groups except for Adult-1 animals. Hyperthyroidism led to a significant decrease in VIP-LI levels in both atria of Neo-S and Neo-T rats. Hyperthyroidism induced in adult rats also decreased VIP-LI levels in both atria. However, this change was only transient. In conclusion, our data have provided new evidence that hyperthyroidism induced during the early neonatal period interferes with the development of VIP-ergic innervation in rat atria. The period of the first few postnatal days seems to be essential for this effect, since VIP-LI concentrations in 60-day-old animals did not significantly differ between Neo-S and Neo-T atria., J. Kuncová, J. Slavíková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32653. Vasodilator action of the S-nitrosothiol, SNAP, in rat Isolated perfused lung
- Creator:
- Emery, C. J.
- Type:
- article, model:article, and TEXT
- Subject:
- SNAP, rat, and pulmonary vasodilatation
- Language:
- English
- Description:
- The pulmonary vasodilator action of an S-nitrosothiol, S-nitroso acetylpenicillamine (SNAP), was investigated in the rat pulmonary vasculature. The influence of its nitric oxide donator property was studied by comparison with the effect of acetylpenicillamine (AP), SNAP minus the nitroso group, and the blockade of nitric oxide release by the L-arginine analogue, L-NAME. In the isolated rat lung perfused with autologous blood at a constant flow rate (1PL), changes in pulmonary artery pressure (Ppa) reflect changes in pulmonary vascular resistance. Dose-response relationships to both SNAP and AP (0.1, 1, 10 and 100 /ug) were established both during normoxic ventilation (air + 5 % CO2; low Ppa) and when Ppa was raised by alveolar hypoxic vasoconstriction (2 % O2 + 5 % CO2). SNAP caused small dose-dependent fall in normoxic Ppa (mean±S.D. 17.4±3.0 mm Hg). in 11 rat IPL % fall of Ppa was 1, 3 and 4 % for 1, 10 and 100 ¡ug, respectively (p<0.01). This fall was more obvious when Ppa was raised by hypoxia (mean Ppa rise (HPV) 11.5±3.8 mm Hg); there was a 22, 55 and 79 % fall in HPV for 1,10 and 100 /ug in 11 rat IPL. The dilatation after 10 /ig SNAP was not consistently affected by 100/rg L-NAME (% fall in HPV pre L-NAME 45±22 % vs 42±23 % post L-NAME). AP had no significant effect on Ppa, causing only small falls in Ppa, equivalent to solvent (saline). There was occasionally a small rise in Ppa with 10 and 100 /tg AP. Thus, the dilator action of SNAP is most likely due to its NO donator property, and is not consistently affected by blockade of endogenous NO release.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32654. Vasopresinový nosní sprej pro lepší orientaci v sociálních vztazích
- Creator:
- Patočka, Jiří
- Type:
- article, model:article, and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32655. Vasopressin in thermoregulation - competitive demands: experimental evidence and theoretical considerations
- Creator:
- Horowitz, M., Epstein, Y., and Shapiro, Y.
- Type:
- article, model:article, and TEXT
- Subject:
- thermoregulation, osmoregulation, vasopressin, and fever
- Language:
- English
- Description:
- Previous studies have substantiated the antipyretic role played by extrahypothalamic limbic system (EXHY-LS) AVP during fever. Repeated attempts to elucidate other thermoregulatory functions of this hormone have failed. Circumstantial evidence, however, suggest central role for this hormone in thermoregulation under hypohydration. Hypohydration, hyperosmolarity and hypovolaemia induce upward shifts in temperature thresholds for activation of heat dissipating mechanisms. When hypovolaemia is superimposed on hyperosmolarity these shifts are additive. Analogously, these two stressors when combined, decrease the osmotic threshold for AVP release. In rats, the elevated temperature thresholds for evaporative cooling and peripheral vasodilation occurring with hypohydration are positively correlated with lower Hypothalamic/EXHY-LS AVP ratio. Reciprocal relations between limbic system and blood AVP contents suggest competitive interaction between central and peripheral demands. Hypothesis for the possible mode of action of central AVP in thermoregulation under hypohydration is discussed.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32656. Vasorelaxation by pinacidil in isolated perfused lungs is enhanced in rats with hypoxic pulmonary hypertension but is dependent on the constrictor
- Creator:
- Wanstall, J. C.
- Type:
- article, model:article, and TEXT
- Subject:
- pinacidil, rat perfused lungs, pulmonary hypertension, hypoxic pulmonary vasoconstriction, and noradrenaline
- Language:
- English
- Description:
- The potassium channel opening drug, pinacidil, has been examined in isolated perfused lungs taken from rats with hypoxic pulmonary hypertension (housed in 10 % oxygen for 7 days) and control rats. Inhibition by pinacidil (1 to 30 //M) of noradrenaline (NA)-induced vasoconstriction (NA infusions; /^-adrenoceptors blocked) and of hypoxic pulmonary vasoconstriction (HPV; ventilation for 3.5 -4.5 min with 0-1 % oxygen) were compared. The vasoconstrictor responses in preparations from control and hypoxic rats, respectively, were (mm Hg) NA 6.6±0.68 (6); 8.2±1.45 (9); HPV 7.8±1.03 (12); 8.8±0.93 (13). These responses were reversibly inhibited by pinacidil. In lungs from control rats pinacidil was 10-fold less potent against NA than against HPV, but in lungs from hypoxic rats it was equipotent against NA and HPV. When tested against NA, but not HPV, pinacidil was significantly more potent in lungs from hypoxic rats than control rats. It is postulated that NA-induced vasoconstriction in lungs from hypoxic rats, and HPV in both groups of rats, involve calcium influx through voltage-operated calcium channels. Consequently, these responses are readily inhibited by drugs such as pinacidil which open potassium channels and hyperpolarise the cell membrane. In contrast in lungs from control rats, NA-induced constriction may involve mainly intracellular calcium release and thus be less readily inhibited by the hyperpolarising effect of pinacidil.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32657. Vasorelaxing action of vasonatrin peptide is associated with activation of large-conductance Ca2+-activated potassium channels in vascular smooth muscle cells
- Creator:
- Yu, J., Zhu, M., Fu, Z., Zhu, X., Zhao, Y., and Chen, B.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, natriuretické peptidy, natriuretic peptides, vasonatrin peptide, vascular smooth muscle cells, calcium-activated potassium channels, cyclic guanosine monophosphate, 14, and 612
- Language:
- English
- Description:
- 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 Ca2+-activated potassium channel (BKCa) via guanylyl cyclase (GC)-coupled natriuretic peptide receptors (NPRs) in vascular smooth muscle cells (VSMCs). Contraction experiments were performed using human radial artery, whereas BKCa 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 BKCa, 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. BKCa 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, BKCa 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-BKCa is one possible signaling system involved in VNP induced relaxation., J. Yu ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32658. Vavraia culicis (Weiser, 1947) Weiser, 1977 revisited: cytological characterisation of a Vavraia culicis-like microsporidium isolated from mosquitoes in Florida and the establishment of Vavraia culicis floridensis subsp. n.
- Creator:
- Vávra, Jiří and Becnel, James J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Microsporidia, mosquitoes, Vavraia, ultrastructure, and light microscopic cytology
- Language:
- English
- Description:
- A brief nomenclatural history of Vavraia culicis (Weiser, 1947), the type species for the genus Vavraia Weiser, 1977, is presented together with a detailed description of the cytological and ultrastructural characteristics of a Vavraia culicis-like microsporidian species isolated from Aedes albopictus (Scuse) in Florida. This ''Florida isolate'', is the only known isolate of a species of the genus Vavraia from mosquitoes propagated in laboratory culture. Although the Florida isolate has been used under the name Vavraia culicis in several molecular phylogeny and host-parasite studies, it has not been structurally characterized and its relationship to the type species Vavraia culicis has never been examined. Structural data strongly support placement of the Florida isolate within the genus Vavraia and indicate its close relationship to both the type species of the genus and to other Vavraia-like mosquito microsporidia to which the name V. culicis has been applied. However, the identity of the Florida isolate with V. culicis (Weiser, 1947) Weiser, 1977 cannot be presently confirmed. Morphometric examination of spores of several Vavraia-like microsporidia isolates from mosquitoes, including the type material of Vavraia culicis, indicates that Vavraia culicis-like microsporidia probably represent not a single species, but a group of closely related organisms. Subspecies status is proposed for the Florida isolate.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32659. Vavřincova vylidněná Praha
- Creator:
- Čornej, Petr
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32660. Vázaný a nevázaný vzor písma u žáků 3. ročníku základní školy
- Creator:
- Kučerová, Olga, Kubín, Daniel, and Kuchraská, Anna
- Type:
- article, model:article, and TEXT
- Subject:
- písmo, kurzíva, Comenia Script, hodnocení písma, handwritting, italics, and handwritting assessment
- Language:
- Czech
- Description:
- Příspěvek1 je věnován popisu a srovnání písemného projevu žáka třetí třídy, který píše v běžném modelu vázaného písma (latinka) a v modelu písma nevázaného (Comenia Script). Odlišuje obtíže v psaní, které jsou pro dané období typické od těch, které by mohly naznačovat závažnější problémy. Žáci, kteří byli zapojeni do výzkumného projektu (N = 180), byli vyučováni metodou psaní Comenia Script a běžnou vázanou latinkou. Na konci třetí třídy (v roce 2013) prošli diagnostickou prověrkou, prostřednictvím které byly sledovány písařské a pisatelské dovednosti v obou modelech psaní. K hodnocení písemných produktů byla upravena hodnotící škála Veverkové a Kucharské (2012), která zahrnovala popis jevů, vážících se na grafomotorické a gramatické aspekty psaní, včetně celkové chybovosti a práce s chybou. Každá sledovaná oblast zahrnovala sérií ukazatelů, jejichž prostřednictvím bylo možno vytvořit ucelenou představu o podobě písemného projevu v daném období. Každý ukazatel byl samostatně bonifikován na tříbodové škále. Díky tomu vznikl celistvý obraz podoby písma současného školáka ve dvou vyučovaných modelech písma ve 3. ročníku. Dosažené výsledky by mohly sloužit v psychologické poradenské praxi. and This study is focused on the comparison of handwriting of pupils in the third grade of elementary school. There were two groups of subjects, the first one used ordinary handwriting and the second used the Comenia Script font. The study describes typical problems related to the learning level of both groups and pinpoints these which could be symptoms of more serious problems. The research sample was a group of 180 pupils divided equally. There was a diagnostic testing at the end of third grade (2013) focused on currently achieved handwriting skills of both groups. The methods and the differences were logged. For evaluation purposes there was used a modified assessing scale of Veverková and Kucharská (2012). It consists of four categories: graphomotoric aspects of handwriting, orthographic aspects of handwriting, the error rate and the ability of correcting errors. Every category contains number of indicators through which we completed overall apprehension of the handwriting level for examined pupils. Every indicator was independently classified at 1–3 scale. Results of this study might be used in the clinical psychological consulting.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public