Skin flux and the venoarteriolar response in essential hypertension.

Vasoconstriction is considered an important factor in patients with hypertension. The presence of skin flow reduction and the decrease in the venoarteriolar response (the skin flow decrease due to postural changes such as standing of lowering the leg below heart level) were studied in normal subjects and in patients with essential hypertension with laser-Doppler flowmetry. Measurements were repeated after a period of four weeks treatment with nifedipine. Laser-Doppler skin flux when the patient was resting supine and with the foot 50 cm below heart level was significantly lower than in normals. Also the venoarteriolar response was significantly reduced in hypertensives. After nifedipine treatment a significant increase in skin flux and improvement of the venoarteriolar response were observed. In conclusion laser-Doppler flowmetry can be used in hypertensives to quantify skin flow reduction, the altered venoarteriolar response and possibly the effects of drugs on the microcirculation.