Autonomy extends to the arterial supply of rapidly growing tumors. Studies on the feeder vessel to carcinoma in rat testis.

There has been longstanding interest in the characteristics of "feeder vessels" to tumors. To develop a convenient model for assessing the determinants of the responsiveness of the arterial blood supply to tumors, we assessed by arteriography the response of the spermatic artery to norepinephrine, vasopressin, and ergonovine after implantation of Walker carcinoma in the testis of the rat. Loss of response to norepinephrine of the spermatic artery supply to the tumor occurred by the fourth day of tumor growth in this model, along the entire length of the spermatic artery. As expected, there was sustained vasoconstriction of the contralateral spermatic artery to the normal testis in response to norepinephrine. Vasopressin and ergonovine exerted no effect, so that the specificity of the loss of response to norepinephrine remains unclear. The spermatic artery provides an accessible and convenient model for studying the blood supply to tumors.