Tissue blood flow and blood flow distribution after administration of dextran 70, dihydroergotamine and their combination. A study in dogs using the radioactive microsphere technique.

The radioactive microsphere technique was used to measure tissue blood flow after administration of dextran 70 and dihydroergotamine, both separate and in combination, in normotensive dogs. Dextran 70 increased cardiac, output and tissue blood flow to most organs. Unchanged blood flow after dextran 70 to CNS, liver (hepatic artery blood flow), adrenals, genitals, uterus and lungs (bronchial artery and arteriovenous shunts) was found. Dihydroergotamine administration did not alter cardiac output. Tissue blood flow to pancreas and thyroid was reduced and CNS-tissue blood flow increased. Heart tissue blood flow was unaffected. When dihydroergotamine was given after dextran 70 had been infused, tissue blood flow returned to baseline values--except for pancreas and thyroid, where tissue blood flow was reduced, and CNS-tissue, where blood flow was increased. When dextran 70 was infused after dihydroergotamine, cardiac output and tissue blood flow remained mainly unchanged.