Ve druhé polovině 20. století byl jedním z ústředních témat vývojové fyziologie problém „vysoké odolnosti novorozených savců vůči kyslíkové nedostatečnosti“. Soustředilo se na něj několik tehdejších předních pracovišť. Článek přináší hlavní experimentální výsledky pracoviště autora, které by mohly inspirovat i současný výzkum.Rozsáhlá série pokusů na mláďatech potkanů naznačila existenci velmi účinného mechanismu, jenž umožňuje novorozeným savcům odolat nedostatku kyslíku. Základem přežití v hypoxickém prostředí (ve stavu kyslíkové nouze) je schopnost nezralé tkáně (nediferencované a dosud nenastavené na homeostatické podmínky při současné absenci regulačních mechanismů) snížit závislost organismu na oxidačních procesech. U nezralého organismu závisí spotřeba na podmínkách prostředí, kdy nabídka kyslíku určuje míru jeho utilizace. Jedním z mechanismů odolnosti novorozeného mozku vůči hypoxii by mohla být i zvýšená efektivita fosforylace, tj. spřaženosti oxidačních dějů s pochody tvorby ATP, která byla pozorována jak na úrovni homogenátu mozkové tkáně, tak na úrovni mitochondrií. Kyslíková nedostatečnost v experimentálních podmínkách na potkanech, ale i v paralelním pozorování u lidských novorozenců vedla k vzestupu zastoupení PUFA omega-3. To by mohlo být interpretováno jako lipogenetický proces, realizovaný elongačními a doprovázený desaturačními pochody v řadě mastných kyselin PUFA omega-3.
In the second half of the 20th century, one of the central themes of developmental physiology was the problem of “high resistance of newborn mammals to oxygen insufficiency.” Several leading laboratories at the time studied the question. The article presents the main experimental results of the author's research group, which could also inspire the current research. An extensive series of experiments on rat pups has indicated the existence of a very effective mechanism that allows newborn mammals to withstand a lack of oxygen. The basis of survival in a hypoxic environment (in a state of oxygen emergency) is the ability of immature tissue (undifferentiated and not yet adjusted to homeostatic conditions in the current absence of regulatory mechanisms), to reduce the body's dependence on oxidative processes. In the immature organism, consumption depends on envi-ronmental conditions, where the supply of oxygen determines the degree of its utilization.One of the mechanisms of resistance of the newborn brain to hypoxia could be the increased efficiency of phosphorylation, i.e. the association of oxidative processes with the processes of ATP production, which was observed both at the level of brain tissue homogenate and at the level of mitochondria.Oxygen deficiency in experimental conditions in rats, but also in parallel observations in human neonates, led to an increase in the proportion of PUFA omega-3. This could be interpreted as a lipogenetic process carried out by elongation and accompanied by desaturation processes in a number of PUFA omega-3 fatty acids..
- MeSH
- hypoxie * patofyziologie MeSH
- lipogeneze fyziologie MeSH
- mitochondrie fyziologie MeSH
- modely u zvířat MeSH
- mozková kůra fyziologie růst a vývoj MeSH
- novorozená zvířata * fyziologie růst a vývoj MeSH
- odolnost vůči nemocem fyziologie MeSH
- potkani Wistar fyziologie růst a vývoj MeSH
- savci fyziologie růst a vývoj MeSH
- spotřeba kyslíku MeSH
- statistika jako téma MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
The behaviour of the nestlings of nocturnal cavity-nesting species has relatively rarely been studied in detail because of problems connected with use of the technical devices required to provide long-term monitoring of individuals. However, long-term observation of nestling behaviour is crucial in order to identify different types of behaviour which may be caused by sibling competition at the end of nesting period. We studied behaviour of 43 Tengmalm's owl (Aegolius funereus) nestlings at 14 nests using a camera and a chip system. The nestlings perched at the nest box entrance from an average age of 28 days from hatching (range 24-34 days) until fledging, spending around 2 hours per day here in total, in periods ranging from a few seconds to 147 min (7.6±10.9 min, mean ± SD). We found that individual duration of perching at the nest box entrance was significantly influenced by nestlings' age and wing length and that the duration of perching at the nest box entrance significantly decreased with time of night. However, during daylight hours, time of day had no effect on either probability or duration of nestlings' perching. We suggest daylight perching at the nest box entrance results from nestlings' preparation for fledging, while individuals perching here during the night may gain an advantageous position for obtaining food from the parents; another possibility at all times of day is that nestlings can reaffirm their social dominance status by monopolizing the nest box entrance.
- MeSH
- audiovizuální záznam MeSH
- fotoperioda MeSH
- hnízdění fyziologie MeSH
- kompetitivní chování fyziologie MeSH
- křídla zvířecí anatomie a histologie fyziologie MeSH
- novorozená zvířata anatomie a histologie fyziologie psychologie MeSH
- Stringiformes anatomie a histologie fyziologie MeSH
- tělesná hmotnost MeSH
- věkové faktory MeSH
- velikost orgánu MeSH
- velikost těla MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim of the present study was to determine effects of methamphetamine (MA) exposure and cross-fostering on thermal nociceptive thresholds in different estrous phases in adult female rats. Rat mothers were exposed daily to injection of MA (5 mg/kg) or saline for 9 weeks: prior to impregnation, throughout gestation and lactation periods. Dams without any injections were used as an absolute control. On postnatal day 1, pups were cross-fostered so that each mother raised four pups of her own and eight pups from the mothers with the other two treatments. Offspring females were tested in adulthood (85-90 days) for thermal nociception as latency [s] of withdrawal reaction of forelimbs, hind limbs, and tail. Our results showed that prenatal MA exposure did not affect the nociception in adulthood, while postnatal MA exposure (i.e., MA administration to lactating mothers) had pro-nociceptive effects. The effect of postnatal MA exposure was apparent in both, fore- and hind limbs, while the latency to tail withdrawal reaction was the same among the groups. In addition, the pro-nociceptive effect of postnatal MA exposure did not depend on estrous cycle. This study indicates that postnatal but not prenatal exposure to MA affects nociception in adult female rats. However, it is still not clear whether the pro-nociceptive effect of postnatal MA exposure is linked to direct action of MA on neuronal organization, or to indirect action of MA mediated by impaired maternal care.
- MeSH
- diestrus účinky léků MeSH
- injekce subkutánní MeSH
- krysa rodu rattus MeSH
- methamfetamin toxicita MeSH
- neurony účinky léků MeSH
- novorozená zvířata fyziologie MeSH
- potkani Wistar MeSH
- práh bolesti účinky léků MeSH
- proestrus účinky léků MeSH
- reakční čas účinky léků MeSH
- sympatomimetika toxicita MeSH
- těhotenství MeSH
- věkové faktory MeSH
- vnímání teploty účinky léků MeSH
- zpožděný efekt prenatální expozice patofyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
The contribution of the sympathetic innervation to the postnatal development of cardiac contractility remains unclear. In this study, the postnatal maturation of cardiac contractility was compared in control rats and rats after chemical sympathectomy. The chemical sympathectomy was induced by administration of 6-hydroxydopamine to newborn rats. At days 20, 40 and 60 of postnatal life, the contractile parameters and concentrations of sympathetic neurotransmitters were measured in both right and left ventricles. In rats with chemical sympathectomy, concentrations of norepinephrine were reduced almost completely in both ventricles at all time points. The contractility of the left ventricle papillary muscles was substantially decreased at all time points. In contrast, the contractility of the right ventricle papillary muscles was decreased only transiently, showing a recovery at day 60 regardless of the permanently decreased concentration of norepinephrine. The concentration of neuropeptide Y, another neurotransmitter present in sympathetic nerves, showed the same developmental trend as contractility: permanent reduction in the left ventricle, transient reduction with a recovery at day 60 in the right ventricle. The data indicate that the sympathetic nervous system plays an important role in the postnatal development of cardiac contractility and neuropeptide Y may contribute to this effect.
- Klíčová slova
- Chemical sympathectomy, Contraction, Neuropeptide Y, Norepinephrine, Rat heart,
- MeSH
- agonisté adrenergních alfa-receptorů farmakologie MeSH
- beta blokátory farmakologie MeSH
- financování organizované MeSH
- funkce levé komory srdeční fyziologie MeSH
- funkce pravé komory srdeční fyziologie MeSH
- kontrakce myokardu fyziologie MeSH
- krysa rodu rattus MeSH
- neuropeptid Y metabolismus MeSH
- noradrenalin metabolismus MeSH
- novorozená zvířata fyziologie MeSH
- oxidopamin MeSH
- papilární svaly fyziologie MeSH
- potkani Wistar MeSH
- propranolol farmakologie MeSH
- stárnutí fyziologie MeSH
- sympatektomie chemická MeSH
- tyramin farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
Hippocampal lesions in newborn rats alter the development of mechanisms involved in the processing of nociception. The hippocampal lesion was induced by the bilateral infusion, into the lateral cerebral ventricles, of 0.25 microL of saline containing either 0.25 micromol quinolinic acid (QUIN) and/or 0.25 micromol N-acetyl-L-aspartyl-L-glutamate (NAAG) on postnatal day 12. The same amount of sterile saline was injected into the sham-operated animals (group SHAM). It was expected that the QUIN- and NAAG-lesioned rats would exhibit some differences in thermal pain perception; however, we wanted to know if the control rats would exhibit, at least in part, similar changes in pain perception as their chemically lesioned siblings with which they were housed. Young adult NAAG-injured rats exhibited increased withdrawal latencies in the tail-flick and plantar tests, whereas young adult QUIN-injured animals exhibited only marginally decreased latencies. Nociceptive responses in the SHAM rats paralleled the littermates that had been neonatally treated with QUIN or NAAG, i.e. the responses in the SHAM(QUIN) group decreased, whereas the responses in the SHAM(NAAG) group increased. No significant changes in nociception were observed in intact animals, regardless of which group they were housed with. Our results show that social factors, which were originally demonstrated only for the pain behavior, may also influence basal nociceptive sensitivity in rats. We concluded that the "sham operation" may have had a long-term, nonspecific impact on nociceptive behavior by inducing behavioral mimicry of other animals.
- MeSH
- dipeptidy farmakologie MeSH
- financování organizované MeSH
- hipokampus zranění MeSH
- interpretace statistických dat MeSH
- krysa rodu rattus MeSH
- kyselina chinolinová farmakologie MeSH
- měření bolesti účinky léků MeSH
- nociceptory fyziologie účinky léků MeSH
- novorozená zvířata fyziologie MeSH
- reakční čas účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
The first step in a study of possible cognitive side effects of topiramate in immature rats is to determine if and how topiramate (TPM) influences motor ability and spontaneous behavior. We therefore studied the effects of TPM on motor performance of 12- and 25-day-old rats using age-appropriate tests. Spontaneous behavior in the open field was studied in 25-day-old animals only. TPM was administered intraperitoneally at 80 and/or 160 mg/kg; control rats were injected with solvent (dimethylsulfoxide). A battery of motor tests was conducted before and 1, 3, and 24 hours after administration; behavior in the open field was recorded 2 and 24 hours after TPM administration. The effects of TPM on motor performance were similar to those of solvent. A few differences were found only at the 3-hour interval in 12-day-old rats. Behavior in the open field was not impaired by TPM; on the contrary, an apparent anxiolytic effect was observed. Habituation (a decrease in locomotor activity during the 5-minute observation period), a form of simple nonassociative learning, was also not compromised by TPM. A single high dose of TPM resulted only in transient changes in motor performance. A possible anxiolytic effect observed in 25-day-old rats should be studied.
- MeSH
- antikonvulziva farmakologie MeSH
- chování zvířat účinky léků MeSH
- financování organizované MeSH
- fruktosa analogy a deriváty farmakologie MeSH
- krysa rodu rattus MeSH
- metoda rotující tyčky MeSH
- novorozená zvířata fyziologie MeSH
- pátrací chování účinky léků MeSH
- pohybová aktivita účinky léků MeSH
- potkani Wistar MeSH
- psychomotorický výkon fyziologie účinky léků MeSH
- tělesná hmotnost účinky léků MeSH
- věkové faktory MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- chování zvířat účinky léků MeSH
- čich účinky záření MeSH
- finanční podpora výzkumu jako téma MeSH
- glutamát sodný toxicita MeSH
- krysa rodu rattus MeSH
- novorozená zvířata fyziologie MeSH
- pohybová aktivita účinky léků MeSH
- potkani Wistar MeSH
- rozpoznávání (psychologie) účinky léků MeSH
- sociální chování MeSH
- těhotenství MeSH
- tělesná hmotnost účinky léků MeSH
- úzkost psychologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- antagonisté excitačních aminokyselin farmakologie MeSH
- antikonvulziva aplikace a dávkování farmakologie MeSH
- finanční podpora výzkumu jako téma MeSH
- krysa rodu rattus MeSH
- novorozená zvířata fyziologie růst a vývoj MeSH
- pohybová aktivita fyziologie účinky léků MeSH
- pyridiny aplikace a dávkování farmakologie MeSH
- receptory metabotropního glutamátu MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
