EFFECTS OF MANNITOL AND IOHEXOL INFUSIONS ON THE RENAL CORTICAL BLOOD-FLOW IN DEHYDRATED MICE

In vivo fluorescence microscopy was used in experimental studies of re nal cortical microcirculation in mice. The effects of intravenous infu sions of equimolar concentrations of mannitol and iohexol were studied in normal lean mice and obese/hyperglycemic mice after dehydration ov ernight. All infusions produced marked effects in distribution and vel ocity of renal cortical blood flow. Initially increased blood flow was seen in a number of capillaries after infusion of both mannitol and i ohexol, and renal cortical blood flow was inhomogeneous for different capillaries. A significantly (p<0.05) larger number of capillaries wit h decreased blood flow, within the first minutes after start of infusi on, was observed after infusion of iohexol to normal mice when the ani mals had been dehydrated overnight. Our results indicate that the mino r adverse effects on renal cortical blood flow caused by the infusion of contrast medium are potentiated by dehydration.