New technique for measurement of microvascular pressure in normal and tumor vessels of rats.

A new type of rat transparent chamber was developed to measure the microvascular pressure. One side of this chamber consists of an airtight space, covered with a thin plastic membrane, through which either normal or tumor microvascular pressure was measured. The microvascular pressure in tumor tissue was usually lower than that in normal subcutis. When the systemic blood pressure was elevated by continuous infusion of angiotensin II, the microvascular pressure in tumor increased markedly. The results are discussed in correlation with the mechanism of enhanced chemotherapeutic effect in cancer by angiotensin II.