Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ATMOSPHERIC PRESSURE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52Linked to original sources
PubMed1983

Tissue distribution of thiopental and diazepam in rats at 71 atmospheres pressure.

35S-thiopental 15 mg/kg and 14C-diazepam 5 mg/kg were injected intravenously in separate groups of rats (n = 6) at 1 ATA air and at 71 ATA air-He. Total radioactivity was measured in the brain, liver, kidney, muscle and fat after 1, 3, 5 and 15 min. The thiopental content was significantly reduced at pressure in the brain at 3, 5 and 15 min. The diazepam content of the brain was significantly reduced at pressure at 1, 5 and 15 min. The liver, muscle and kidney tissue generally contained slightly less of either drug at pressure, particularly at the earliest sampling times.

Animals↗
PubMed1990

[Transmission of changes in the external ear atmospheric pressure to the perilymph].

Using guinea pig, pressures in the external ear canal, in the middle ear and in the perilymph were registered simultaneously, while pressure was applied to the external ear canal using an impedance audiometer. In the first experiment, applied pressure was changed in the range from 200 mmH2O to -200 mmH2O with and without the opening of the otic bulla. The change in the perilymphatic pressure with the opening was smaller than that without the opening. The result indicates that the external ear pressure is transmitted to the perilymph not only via the ossicular chain but also via the middle ear cavity without the opening, while it is exclusively transmitted via the ossicular chain with the opening. Pressure transmission to the perilymph was significantly impaired either by disrupting the ossicular chain or by closing the round window niche, especially by the latter. Thus the middle ear cavity itself plays an important role in pressure transmission from the external ear canal to the perilymph mainly via the round window. In the second experiment, applied pressure to the external ear canal was changed in the range from 1000 mmH2O to -1000 mmH2O after the Eustachian tube being closed. Between 400 mmH2O and -200 mmH2O, the middle ear and perilymphatic pressures paralleled well with the applied pressure. Beyond these levels, the middle ear pressure increased or decreased in response to the applied pressure but the perilymphatic pressure reversed against the middle ear pressure. Communication between perilymph and cerebrospinal fluid via the cochlear aqueduct is thought to be a major factor causing this reversal which, in turn, aggravates pressure gradient between the middle ear and the perilymph.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗