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212. Age, genetic characteristics and number of cycles are critical factors to consider for successful protection of the murine heart with postconditioning
- Creator:
- Somers, S. J., Lacerda, L., Opie, L., and Lecour, S.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, ischemie, ischemia, reperfusion, postconditioning, 14, and 612
- Language:
- English
- Description:
- Postconditioning (PostC) is a re cently discovered phenomenon whereby brief repetitive cycles of ischaemia with intermittent reperfusion following prolonged is chaemia elicit cardioprotection. This study investigated whether the age, genetic characteristics or number of repetitive cycles influenced the protective effect of PostC in mice. C57BL/6 floxed or non-floxed STAT-3 mice aged between 14-16 weeks (young) or 18-20 weeks (older) were perfused on a Langendorff apparatus and subjected to 35 min global ischaemia and 45 min reperfusion. PostC was elicited by either 3 (PostC-3) or 6 cycles (PostC-6) of 10s ischaemia and 10 s reperfusion. PostC-3 and PostC-6 in both young and older non-floxed mice reduced the myocar dial infarct size. In contrast, only PostC-3 reduced myocardial infarct size in young floxed mice. Neither PostC-3 nor PostC-6 reduced the in farct in older floxed mice. Our data reveal that genetic characteristics, a minute difference in age or the nu mber of postconditioning cycles are critical factors to be consid ered for the successful effect of ischaemic postconditioning in a murine model. Moreover, these factors should be taken into consideration for future experimental research or clinical applications of this protective phenomenon., S. J. Somers ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
213. Age-associated endothelial dysfunction in rat mesenteric arteries: roles of calcium-activated K+ channels (Kca)
- Creator:
- Zhou, E., Qing, D., and Li, J.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, stárnutí, endoteliální dysfunkce, acetylcholin, aging, endothelial dysfunction, acetylcholine, potassium channels, mesenteric artery, 14, and 612
- Language:
- English
- Description:
- Age-associated changes in large blood vessels were characterized by increased arterial wall thickness, luminal dilation and impaired endothelial function. But little is known about the effect of age on structural and functional changes in small resistance arteries. The mechanisms underlying age-associated endothelial dysfunction in rat mesenteric resistance arteries were investigated in the present study. Small rat mesenteric arteries were excised and cannulated, and vascular endothelial functions were tested by acetylcholine (ACh). Our experiments showed (1) endotheliumdependent vasorelaxation induced by ACh was reduced in aged mesenteric arteries; (2) blockade of Kca channels markedly reduced the vasodilation in young and adult rats, the resultant reduction in aged rats was much smaller compared with young and adult rats; (3) inhibition of endothelial nitric oxide synthase (NOS) resulted in a significant reduction of vasodilation in young and adult, but there was a smaller reduction in aged rats. The results suggest that (1) endothelial function was impaired in mesenteric arteries of aged rats; (2) both Kca channels and nitric oxide (NO) contribute together to the ACh-induced vasorelaxation in small mesenteric arteries, and (3) both the impairment of Kca channel function and decreased NO account for the age-related endothelial dysfunction., E. Zhou, D. Qing, J. Li., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
214. Age-dependent effect of long-term microwave radiation on postnatal neurogenesis in rats: morphological and behavioral study
- Creator:
- Raček, A., Katarína Beňová, Arnoul, P., Závodská, M., Angelidis, A., Cigánková, V., Šimaiová, V., and Enikö Račeková
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- mikrovlnné záření, buněčná smrt, microwave radiation, cell death, adult neurogenesis, proliferation, rostral migratory stream, 14, and 612
- Language:
- English
- Description:
- Processes of adult neurogenesis can be influenced by environmental factors. Here, we investigated the effect of microwave radiation (MWR) on proliferation and cell dying in the rat rostral migratory stream (RMS) - a migration route for the neuroblasts of the subventricular zone. Adult and juvenile (two weeks old) rats were exposed to a pulsed-wave MWR at the frequency of 2.45 GHz for 1 or 3 h daily during 3 weeks. Adult rats were divided into two groups: without survival and with two weeks survival after irradiation. Juvenile rats survived till adulthood, when were tested in the light/dark test. Proliferating cells in the RMS were labeled by Ki-67; dying cells were visualized by Fluoro-Jade C histochemistry. In both groups of rats irradiated as adults we have observed significant decrease of the number of dividing cells within the RMS. Exposure of juvenile rats to MWR induced only slight decrease in proliferation, however, it strikingly affected cell death even two months following irradiation. In addition, these rats displayed locomotor hyperactivity and decreased risk assessment in adulthood. Our results suggest that the long-lasting influence of radiation is manifested by affected cell survival and changes in animals´ behavior., A. Raček, K. Beňová, P. Arnoul, M. Závodská, A. Angelidis, V. Cigánková, V. Šimaiová, E. Račeková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
215. Age-dependent effect of oxidative stress on cardiac sarcoplasmic reticulum vesicles
- Creator:
- Eva Babušíková, Miloš Jeseňák, Dušan Dobrota, Narcisa Tribulová, and Peter Kaplán
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Experimentální medicína, kardiovaskulární fyziologie, oxidační stres, srdce, cardiovascular physiology, oxidative stress, heart, reactive oxygen species, protein damage, 14, and 616-092
- Language:
- English
- Description:
- The oxidative stress hypothesis of aging suggests that accumulation of oxidative damage is a key factor of the alterations in physiological function during aging. We studied age-related sensitivity to oxidative modifications of proteins and lipids of cardiac sarcoplasmic reticulum (SR) isolated from 6-, 15- and 26-month-old rats. Oxidative stress was generated in vitro by exposing SR vesicles to 0.1 mmol/l FeSO4/EDTA + 1 mmol/l H2O2 at 37 °C for 60 min. In all groups, oxidative stress was associated with decreased membrane surface hydrophobicity, as detected by 1-anilino-8-naphthalenesulfonate as a probe. Structural changes in SR membranes were accompanied by degradation of tryptophan and significant accumulation of protein dityrosines, protein conjugates with lipid peroxidation products, conjugated dienes and thiobarbituric acid reactive substances. The sensitivity to oxidative damage was most pronounced in SR of 26-month-old rat. Our results indicate that aging and oxidative stress are associated with accumulation of oxidatively damaged proteins and lipids and these changes could contribute to cardiovascular injury., E. Babušíková, M. Jeseňák, D. Dobrota, N. Tribulová, P. Kaplán., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
216. Age-dependent expression of 5alpha-reductase and androgen receptors mRNA by the canine prostate
- Creator:
- Shidaifat, F.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, prostata, králík, physiology, prostate, Oryctolagus, androgen receptors, 5α-reductase, 14, and 612
- Language:
- English
- Description:
- The growth of the prostate gland is androgen-dependent. Testosterone is converted to the most potent dihydrotestosterone (DHT) by 5α-reductase within the prostate. Androgen interacts with androgen receptors (AR) to regulate normal growth of the prostate and has also been implicated in both the progression of benign prostate hyperplasia and prostate cancer. This study was conducted to compare the mRNA expression of AR and 5α-reductase by the prostate gland from three age categories: immature, young-mature and old dogs. Quantitative gene expression was assessed by the real-time PCR and the results were expressed as a relative mRNA expression of the target gene. This study revealed that there was no significant difference in the mRNA expression of the AR gene by the prostate gland of immature, young and old dogs. In contrast, there is a highly significant (P<0.001) down-regulation in 5α-reductase gene by the prostate of young and old dogs as compared with immature dogs. However, there is no significant difference in mRNA expression of the 5α-reductase gene by the prostate gland from young and old dogs. This differential expression of AR and 5α-reductase genes, which are involved in the regulation of androgen effect on prostate gland, might reflect an age-dependent growth requirement of the gland for androgens., F. Shidaifat., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
217. Age-related changes of human balance during quiet stance
- Creator:
- Abrahamová, D. and František Hlavačka
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, věk, acidobazická rovnováha, physiology, age, acid-base equilibrium, human balance, body sway, quiet stance, 14, and 612
- Language:
- English
- Description:
- Certain aspects of balance control change with age, resulting in a slight postural instability. We examined healthy subjects between 20-82 years of age during the quiet stance under static conditions: at stance on a firm surface and/or on a compliant surface with eyes either open or closed. Body sway was evaluated from centre of foot pressure (CoP) positions during a 50 sec interval. The seven CoP parameters were evaluated to assess quiet stance and were analyzed in three age groups: juniors, middle-aged and seniors. The regression analysis showed evident increase of body sway over 60 years of age. We found that CoP parameters were significantly different when comparing juniors and seniors in all static conditions. The most sensitive view on postural steadiness during quiet stance was provided by CoP amplitude and velocity in AP direction and root mean square (RMS) of statokinesigram. New physiological ranges of RMS parameter in each condition for each age group of healthy subjects were determined. Our results showed that CoP data from force platform in quiet stance may indicate small balance impairment due to age. The determined physiological ranges of RMS will be useful for better distinguishing between small postural instability due to aging in contrast to pathological processes in the human postural control., D. Abrahamová, F. Hlavačka., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
218. Age-related endothelial dysfunction with respect to nitric oxide, endothelium-derived hyperpolarizing factor and cyclooxygenase products
- Creator:
- Matz, R. L., Schott, C., Stoclet, J. C., and Ramaroson Andriantsitohaina
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, endoteliální dysfunkce, cyklooxygenáza 2, endothelial dysfunction, cyclooxygenase 2, vascular aging, EDHF, 14, and 612
- Language:
- English
- Description:
- Vascular aging is associated with both structural and functional changes that can take place at the level of the endothelium, vascular smooth muscle cells and the extracellular matrix of blood vessels. With regard to the endothelium, reduced vasodilatation in response to agonists occurs in large conduit arteries as well as in resistance arteries with aging. Reviews concerning the different hypotheses that may account for this endothelial dysfunction have pointed out alterations in the equilibrium between endothelium-derived relaxing and constricting factors. Thus, a decreased vasorelaxation due to nitric oxide and, in some arteries, endothelium-derived hyperpolarizing factor as well as an increased vasoconstriction mediated by cyclooxygenase products such as thromboxane A2 are likely to occur in age-induced impairment of endothelial vasodilatation. Furthermore, enhanced oxidative stress plays a critical role in the deleterious effect of aging on the endothelium by means of nitric oxide breakdown due to reactive oxygen species. The relative contribution of the above phenomenon in age-related endothelial dysfunction is highly dependent on the species and type of vascular bed., R. L. Matz, C. Schott, J. C. Stoclet, R. Andriantsitohaina., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
219. Aged male and female spontaneously hypertensive rats benefit from n-3 polyunsaturated fatty acids supplementation
- Creator:
- Mitašíková, M., Šmidová, S., Mascaliová, A., Knezl, V., Katarína Dlugošová, Ľudmila Okruhlicová, Weismann, P., and Narcisa Tribulová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Experimentální medicína, kardiovaskulární fyziologie, fibrilace srdce, myokard, cardiovascular physiology, heart fibrillation, myocardium, spontaneously hypertensive rats (SHR), ventricular fibrilation, connexin-43, myocardial enzymes, DPP4, ultrastructure, 14, and 616-092
- Language:
- English
- Description:
- Hypertension-induced myocardial metabolic, structural and electrophysiological remodeling deteriorates with aging and contributes to both heart failure and occurrence of malignant arrhythmias. It has been shown in clinical trials that n-3 polyunsaturated fatty acids (n-3 PUFA) reduce the incidence of cardiovascular diseases and sudden cardiac death. We investigated the cardioprotective effects of n-3 PUFA in aged spontaneously hypertensive rats (SHR) and possible cellular mechanisms involved. Male and female 14-month-old SHR were fed with n-3 PUFA (Vesteralens, Norway, 20 mg/day for two months) and compared with untreated SHR. Results showed that n-3 PUFA supplementation led to 1) significant decline of blood pressure; 2) suppression of inducible ventricular fibrillation (VF) by 57 % (male) and 67 % (female) , although the arrhythmogenic substrates, like fibrosis, hypertrophy and abnormal gap junctions distribution were not eliminated; 3) preservation of the cardiomyocytes and the inte grity of their junctions; 4) enhancement of energetic metabolism enzyme activity; 5) augmentation of capillary density associated with increased alkaline phosphatase and decreased dipeptidyl peptidase-4 (DPP4) activity and 6/ increase in gap junction channel connexin-43 expression. Thus, aged male as well as female SHR benefit from n-3 PUFA supplementation that results in decrease in VF susceptibility, partly due to an improvement of myocardial metabolic state, cardiomyocyte and cell-to-cell junctions integrity and Cx43 up-regulation., M. Mitašíková, S. Šmidová, A. Mascaliová, V. Knezl, K. Dlugošová, Ľ. Okruhlicová, P. Weismann, N. Tribulová., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
220. Ageing of historical ceramics
- Creator:
- Vladimír Hanykýř, Koužková, Alexandra, Petr Bouška, and Miroslav Vokáč
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, historická keramika, historical ceramics, irreversible moisture expansion, fired roof tiles, dilatometric measurements, noncrystalline phase, 7, and 551
- Language:
- English
- Description:
- Irreversible moisture expansion of specimens made from porous ceramics of historical fired tiles is analysed here. Irreversible moisture expansion values, which reflect the rate of body ageing, were determined by heating at a temperature of 650 °C for 20 minutes and by repeated dilatometric measurement until a te mperature of 700 °C. To evaluate body ageing due to moisture expansion, it is necessary to specify the non-crystalline phase content. The causative factors influencing body ageing can be determined on bodies that have comparable non-crystalline phase content and are of similar chemical and mineralogical composition. Sufficient data set may facilitate a roughestimate of the age of historical ceramics., Vladimír Hanykýř, Alexandra Koužková, Petr Bouška and Miroslav Vokáč., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public