Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0242706 (hyperoxia)
 5,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously found an age-dependent relaxing effect of furosemide in normal fetal, newborn, and adult guinea pig airways with fetal trachea exhibiting the greatest relaxation and adult tissue the least. This study was designed to expand upon this finding by determining if in vivo hyperoxic exposure would influence in vitro airway relaxation mediated by the loop diuretics, furosemide and ethacrynic acid, and the beta 2-adrenoceptor agonist, salbutamol. Newborn guinea pigs were raised in > 95% FiO2 until ill; controls in room air. Isometric relaxation to 3 x 10(-5) M furosemide, 3 x 10(-6) M ethacrynic acid, or 10(-8)-10(-6) M salbutamol was recorded in 3 x 10(-6) M histamine-constricted airway rings. Ethacrynic acid, like furosemide, relaxed newborn guinea pig airways. Hyperoxia did not alter the contractile effect of 3 x 10(-6) M histamine but did significantly decrease the relaxing effect of furosemide, ethacrynic acid, and salbutamol. Loop diuretic mediated airway relaxation was accentuated in HEPES buffer when compared with Krebs, whereas salbutamol-mediated relaxation was unaffected. These results suggest that hyperoxia nonspecifically decreases airway responsiveness to the relaxing agents studied.
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PMID:Acute hyperoxic injury attenuates the relaxing effects of "loop" diuretics and salbutamol on large airways of newborn guinea pigs. 749 47

Paraganglia resembling the carotid body have been described in the superior laryngeal nerve (SLN) of the rat and the aim of the present study was to determine if this tissue is chemosensitive. We developed a novel isolated SLN preparation superfused with HEPES-buffered Tyrode solution at 35 degrees C in vitro. A glass suction microelectrode was used to record the electrical activity of single SLN units and a micropipette was used to pressure-eject small volumes of sodium cyanide (NaCN; 250-500 ng in 5 microl) near glomus tissue located at the main bifurcation of the SLN. The duration of the NaCN response and the number of spikes evoked after application of NaCN were compared in normoxia and hyperoxia (PO2 > 300 mmHg). Hyperoxia significantly reduced the duration and spike number of the NaCN response and a negative linear correlation existed between PO2 and response duration. In addition, hypoxia (PO2 < 60 mmHg) triggered SLN firing. Therefore, we can conclude that the paraganglia of the SLN are not only morphologically similar to the carotid body but are also excited by similar stimuli.
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PMID:Arterial chemoreceptors in the superior laryngeal nerve of the rat. 1523 64