{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,20]],"date-time":"2026-02-20T22:57:38Z","timestamp":1771628258367,"version":"3.50.1"},"reference-count":0,"publisher":"American Physiological Society","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Applied Physiology"],"published-print":{"date-parts":[[1986,5,1]]},"abstract":"<jats:p> Nine unanesthetized, chronically instrumented, female miniature swine (MS) (avg wt, 39.7 kg) were exposed to head-to-tail inertial load (+Gz) levels of +3, +5, and +7 Gz for 60 s, with and without anti-G-suit inflation. Venous flow (VF) was measured by an electromagnetic flow sensor around the inferior thoracic vena cava at the diaphragm. Central venous pressure (CVP), abdominal venous pressure (AVP), eye-level blood pressure (ELBP), and esophageal pressure (EP) were also measured before, during, and after +Gz. There was a progressive significant decrease from control of both ELBP (P less than 0.001) and VF (P less than 0.05) during the three +Gz exposures, both with and without G-suit inflation. Without G-suit inflation, most of the MS were unable to tolerate +5 and +7 Gz. Although VF was significantly (P less than 0.02) improved by G-suit inflation during +Gz there was no significant difference in VF between the three +Gz levels, with or without G-suit inflation. The MS does a spontaneous straining maneuver (cyclic Valsalva) during +Gz with G-suit support. Using EP as a trigger, the data were grouped as strain or no strain (relaxation). A continuous AVP-to-CVP gradient existed during G-suit inflation, which increased dramatically during no strain with increasing +Gz, and was associated with an increase in VF. Thus, the majority of VF occurred during relaxation between strains, even though relaxation time was shortened as +Gz increased. Although ELBP is obviously dependent on cardiac output and venous return, the progressive reduction in ELBP with increased +Gz loads was not significantly related to changes in VF at the diaphragm which was maintained, although at a reduced rate, by the AVP-to-CVP gradient during G-suit inflation. <\/jats:p>","DOI":"10.1152\/jappl.1986.60.5.1628","type":"journal-article","created":{"date-parts":[[2017,12,21]],"date-time":"2017-12-21T05:54:00Z","timestamp":1513835640000},"page":"1628-1637","source":"Crossref","is-referenced-by-count":6,"title":["Hemodynamics of miniature swine during +Gz stress with and without anti-G support"],"prefix":"10.1152","volume":"60","author":[{"given":"J. W.","family":"Burns","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M. J.","family":"Parnell","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R. R.","family":"Burton","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"24","container-title":["Journal of Applied Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/jappl.1986.60.5.1628","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,9,8]],"date-time":"2019-09-08T10:58:20Z","timestamp":1567940300000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/jappl.1986.60.5.1628"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1986,5,1]]},"references-count":0,"journal-issue":{"issue":"5","published-print":{"date-parts":[[1986,5,1]]}},"alternative-id":["10.1152\/jappl.1986.60.5.1628"],"URL":"https:\/\/doi.org\/10.1152\/jappl.1986.60.5.1628","relation":{},"ISSN":["8750-7587","1522-1601"],"issn-type":[{"value":"8750-7587","type":"print"},{"value":"1522-1601","type":"electronic"}],"subject":[],"published":{"date-parts":[[1986,5,1]]}}}