Blood supply to the testis of a Brazilian marsupial (Didelphis azarae) and its abdominotesticular temperature gradient.

The testicular arteries of Didelphis azarae originate from the abdominal aorta either independently from each other or by way of a common trunk. Accessory testicular arteries may be found. At the spermatic cord they form a rete mirabile having 26.8 +/- 5.0 and 29.3 +/- 4.9 slender branches on the right and left sides, respectively. The arterial branches are intermingled with veins of similar caliber and number. Near the testis the branches of the rete reunite in a single vessel which then penetrates the parenchyma of the testis. Inside the testis the artery divides usually into two main branches that course toward the caudal pole. The rectal, scrotal and testicular temperatures were 32, 28.5 and 30.4 degrees C, respectively, appearing than an abdominotesticular gradient temperature exists in this animal. Whether this mechanism is thermoregulatory for the normal spermatogenesis cannot be inferred from the present work.