[Establishment of cervical lymph node metastasis in model rats and its microcirculation characteristics]

To determine the effects of vasoactive agents on blood flow in lymph node metastases, the blood flow in the cervical lymph node metastases and normal tissue were meassured using a hydrogen clearance method, at normotensive state, angiotensin I (A I) induced hypertensive state and sodium nitroprusside (SNP) induced hypotensive state. The metastases occurred frequently in the cervical lymph nodes of 17 rats on day 11-14 after Yoshida ascites hepatoma. AH109A cells were subcutaneously inoculated into back of auricule of 20 rats. The blood flow in the liver, brain and bone marrow of normal rats was of no significant changes when the mean arterial blood pressure (MABP) was elevated to approximately 20 kPa by infusion of A I and decreased to approximately 9.06 kPa by infusion of SNP. But the blood flow in the metastatic lymph nodes was increased from 1.42 +/- 0.48 ml.kg-1/s to 3.45 +/- 1.33 ml.kg-1/s (n = 13, P < 0.05) when the MABP was elevated from 14.81 +/- 1.04 kPa to 18.93 +/- 0.92 kPa by A I. On the contrary, the blood flow in the metastatic lymph node was decreased to 0.55 +/- 0.25 ml.kg-1/s (n = 13, P < 0.05) when the MABP was decreased to 8.84 +/- 0.63 kPa by SNP. The results indicated that microcirculation characteristics in the cervical lymph node metastases were different from those in the normal tissues. A I induced hypertension was useful to selectively improve delivery of chemotherapeutic drugs to the site of metastases. On the other hand, SNP induced hypotension may be useful to suppress washout of the drugs.