Response of the rabbit cutaneous microcirculation to prostanoid modifiers as determined by laser Doppler flowmetry

The cutaneous microvascular flow of the rabbit epigastric island flap under the influence of various prostanoid modifiers has been determined semiquantitatively with a Laser Doppler flowmeter. Infused prostacyclin, diluted with arterial blood to an estimated concentration of 2.5 ng/ml in the microvasculature, increased the microvascular blood flow to approximately 130% of the buffer control. The three thromboxane synthetase inhibitors tested--dazoxiben hydrochloride, UK-38,485, and 7-(1-imidazolyl) heptanoic acid--at concentrations up to 3 X 10(-5) M in the microvasculature, failed to induce any change in blood flow compared to a control neutral-buffered saline infusion. Preliminary results also found that the lipoxygenase inhibitor Bay g6575 did not alter microvascular flow up to 7 X 10(-6) M, but the prostacyclin analog carbacyclin at 30 ng/ml in the microvasculature induced a similar response to 2.5 ng/ml prostacyclin. While such responses are well known for the major vessels, this is one of the few reports with semiquantitative data on the influence of prostanoid synthesis modifiers on blood flow for the microcirculation.