Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  acute hypoxia
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1
Content available remote

Hypoxic ventilatory profile in the anesthetized rat

100%
Marczak M., Kolesnikova E. E., Pokorski M.
Journal of Physiology and Pharmacology. Supplement
|
2004
|
tom 55
|
nr 3
89-94
In the present study we investigated whether hypocapnia that accompanies hypoxic hyperventilation might affect the biphasic, stimulatory/depressant, ventilatory response to hypoxia. The experiments were carried out in anesthetized, vagotomized, spontaneously breathing, and poikilocapnic rats. The animals were subjected to acute steady-state hypoxia consisting of 12% O2 in N2 in inspiratory mixture. Ventilation and its frequency and volume components were assessed from the integrated electromyographic activity of the diaphragm. We found that despite the development of significant hypocapnia, the hypoxic ventilatory response consisted of rapid stimulation followed by a gradual decline. The frequency component contributed more to the ventilatory increase than that of volume. The results indicate that the hypoxic ventilatory profile in the anesthetized poikilocapnic rat resembles that known to be present during isocapnia. We conclude that hypocapnia neither hampers the hypoxic ventilatory reactivity nor alters the biphasic hypoxic ventilatory profile. These observations may aid planning experimental rat model studies.
2
Content available remote

Atrial natriuretic peptide ameliorates hypoxic pulmonary vasoconstriction without influencing systemic circulation

100%
Hohne C., Drzimalla M., Krebs M. O., Boemke W., Kaczmarczyk G.
Journal of Physiology and Pharmacology
|
2003
|
tom 54
|
nr 4
Hypoxic pulmonary vasoconstriction (HPV) is encountered during ascent to high altitude. Atrial natriuretic peptide (ANP) could be an option to treat HPV because of its natriuretic, diuretic, and vasodilatory properties. Data on effects of ANP on pulmonary and systemic circulation during HVP are conflicting, partly owing to anesthesia, surgical stress or uncontrolled dietary conditions. Therefore, ten conscious, chronically tracheotomized dogs were studied under standardized dietary conditions. The dogs were trained to breathe spontaneously at a ventilator circuit. Protocol: 30min of normoxia [inspiratory oxygen fraction (FiO2)=0.21] were followed by 30min of hypoxia without ANP infusion (Hypoxia I, FiO2=0.1). While maintaining hypoxia an intravenous infusion of atrial natriuretic peptide was started with 50ng·kg body wt-1·min-1 for 30min (Hypoxia+ANP1=low dose), followed by 1000ng·kg body wt-1·min-1 for 30min (Hypoxia+ANP2=high dose). Thereafter, ANP infusion was stopped and hypoxia maintained for a final 30min (Hypoxia II). Compared to normoxia, mean pulmonary arterial pressure (MPAP) (16±0.7 vs. 26±1.3mmHg) and pulmonary vascular resistance (PVR) (448±28 vs. 764±89dyn·s-1·cm-5) increased during Hypoxia I and decreased during Hypoxia+ANP 1 (MPAP 20±1mmHg, PVR 542±55dyn·s-1·cm-5) (P<0.05). The higher dose of ANP did not further decrease MPAP or PVR, but started to have a tendency to decrease mean arterial pressure and cardiac output. We conclude that low dose ANP is able to reduce HPV without affecting systemic circulation during acute hypoxia.
3
Content available remote

Reactivity of chicken chorioallantoic arteries, avian homologue of human fetoplacental arteries

84%
Lindgren I., Zoer B., Altimiras J., Villamor E.
Journal of Physiology and Pharmacology
|
2010
|
tom 61
|
nr 5
4

Effect of MK-801 and acute prenatal hypoxia on optical density of mi-opioid receptors in developing rat brain

84%
Kraczkowski J., Smolen A., Billewicz-Kraczkowska A., Semczuk M.
Polish Journal of Environmental Studies
|
2004
|
tom 13
|
nr Suppl.2, Part 1
Hypoxia induces an elevation of excitotoxic amino acid concentrations and may influence hypoxic-in- duced basal ganglia injury. During pregnancy, hypoxia as the destructive factor of CNS alters concentration and mental retardation during childhood. The NMDA antagonist, MK-801, is known to block the effect of amino acids and protect the developing brain against hypoxic insults. To test the hypothesis that MK-801 change prenatal hypoxia affects on the optical density of the μ-opioid receptor system in the developing brain, we quantified optical density of the μ-opioid receptors in several areas of newborn rat brain. In the analysed cerebral structures of rats' brains short-lasting hypoxia leads to the decrease in optical density of n-opioid receptors. MK-801 lessens optical density of μ-opioid receptors in CPu, NA and LMPoA structures.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.