Cardio-vascular and metabolic alterations caused by hemorrhage in fed and starved rats.

Non-starved (fed) and starved rats, sedated with a neurolept analgesic, were subjected to 45 min of hemorrhagic hypotension. The hemorrhage inflicted did not cause hypoxic changes, and left fed and starved animals with the same residual blood volume. Fed animals developed a state of hyperglycemic hyperosmolality and their free fatty acids tended to rise, while these observations were modified among starved animals. After 15 min of hemorrhage the cardiovascular parameters were the same in fed and starved animals, but at 45 min striking differences were observed. In fed animals, cardiac output, stroke volume, skin and muscle flows were substantially higher than starved animal values, while the latter animals had a higher heart rate and peripheral resistance. These effects are attributed to the state of hyperosmolality developed by the fed animals, and can explain the association between nutritional status and survival in hemorrhage.