Effects of Normobaric and Hyperbaric Oxygen on Survival, Regional Blood Flow and Tissue Oxygen Tension in Hemorrhagic Shock in Rats.
Final rept. 30 Sep 92-29 Sep 93,
CARMEL HOSPITAL HAIFA (ISRAEL)
Pagination or Media Count:
This study investigated mechanisms of the hemodynamic effects of oxygen in hemorrhagic shock induced by bleeding 35 of the total blood volume in rats. Hemorrhage induced a marked decrease in mean arterial blood pressure MABP, a 40 decrease in blood flows to the hind quarters, the biceps femoris muscle, and the small bowel, as well as a 62 decrease in superior mesenteric artery SMA flow. This was accompanied by a 73 increase in resistance in the SMA vascular bed. Inhalation of 100 oxygen induced a significant increase of 33 or -3 mmHg in MABP. This was accompanied by a significant increase in vascular resistance in the hind quarters and a concomitant decrease in blood flows in the distal aorta and the biceps femoris muscle. In contrast, oxygen did not change vascular resistance in the SMA bed, and induced a significant increase in blood flow to the SMA and small bowel. Administration of L-Arginine 100 mgkg i.v completely abolished the effects of oxygen on blood pressure and reversed its effects on blood flow and resistance in the hind quarters and biceps femoris muscle.
- Medicine and Medical Research
- Anatomy and Physiology