title: Regional blood flow in sciatic nerve, biceps femoris muscle, and truncal skin in response to hemorrhagic hypotension.
abstract: Regional blood flow was measured simultaneously in rat sciatic nerves (NBF), truncal skin (SBF), and biceps femoris muscles (MBF) after graded hemorrhages. A modified 14C-butanol "indicator-fractionation" technique was used. In controls NBF was 11.4 +/- 1.38 ml X min-1 X 100 gm-1 and did not differ significantly between limbs. After hypotension, NBF was: 101 mm Hg, 7.7 +/- 1.3; 83 mm Hg, 5.3 +/- 0.6; 62 mm Hg, 4.1 +/- 0.6; 38 mm Hg, 3.1 +/- 0.3. The relationship between NBF and MAP was linear: (r = 0.56; p less than 0.001). SBF also declined linearly in hypotension (r = 0.54; p less than 0.01), but MBF did not change significantly. No significant change in nerve vascular resistance occurred with hypotension but muscle vascular resistance declined progressively. The data indicate a striking absence of autoregulation of NBF, but MBF, as expected, displayed close autoregulation. The vascular mechanisms which regulate resting NBF following hemorrhage differ from those in both muscle and skin: during hypotension, the calculated neurovascular resistance was unchanged, while the resistance in muscle fell and that in the skin increased.
authors: Department of Surgery Washington University School of Medicine, St. Louis, Missouri.
authors: H
authors: H
authors: Sugimoto
authors: W W
authors: WW
authors: Monafo
mesh_terms: D000818:Animals; D006470:Hemorrhage / Q000150:complications* / Q000503:physiopathology; D007022:Hypotension / Q000209:etiology / Q000503:physiopathology*; D009132:Muscles / Q000098:blood supply*; D051381:Rats; D012039:Regional Blood Flow; D012584:Sciatic Nerve / Q000098:blood supply*; D012867:Skin / Q000098:blood supply*; D013848:Thigh