Collin O, Damber J E, Bergh A
Department of Anatomy, Umeå University, Sweden.
J Androl. 1996 Jul-Aug;17(4):360-6.
Endothelin-1 (ET-1), a well-known vasoconstrictor substance, is present in the testis but its functional role is unknown. The present study was undertaken to elucidate whether ET-1 may influence testicular blood flow. ET-1 (0.1, 1, 10, 100 ng), an ETA antagonist (BQ123; 0.01, 1, 100 micrograms), or saline were administered by intratesticular injections (0.1 ml) in adult rats. The effect on testicular blood flow was monitored using a laser Doppler flowmeter. The localization of immunoreactive ET-1 (irET-1) was studied by immunohistochemistry and the testicular irET-1 concentration was measured in normal and human chorionic gonadotrophin (hCG)-treated rats using a radioimmunoassay. ET-1 injection, in a dose-related way acutely decreased testicular blood flow and this effect was blocked by an ETA antagonist. The antagonist itself did not, however, influence testicular blood flow. Accumulation of polymorphonuclear leukocytes was observed in testicular venules 2 hours after ET-1 injection. Immunoreactive ET-1 was observed in Leydig, Sertoli, and endothelial cells. The testicular irET-1 content was increased 2-fold by hCG stimulation but local injection of the ET-1 antagonist did not influence testicular blood flow in hCG-treated rats. The present study suggests that ET-1 could be a hormonally regulated and locally produced modulator of testicular blood flow and microcirculation.
内皮素 -1（ET -1）是一种著名的血管收缩物质，存在于睾丸中，但其功能作用尚不清楚。本研究旨在阐明ET -1是否可能影响睾丸血流。通过向成年大鼠睾丸内注射（0.1毫升）给予ET -1（0.1、1、10、100纳克）、一种ETA拮抗剂（BQ123；0.01、1、100微克）或生理盐水。使用激光多普勒血流仪监测对睾丸血流的影响。通过免疫组织化学研究免疫反应性ET -1（irET -1）的定位，并使用放射免疫测定法测量正常和人绒毛膜促性腺激素（hCG）处理的大鼠睾丸中的irET -1浓度。ET -1注射以剂量相关的方式急性降低睾丸血流，并且这种作用被ETA拮抗剂阻断。然而，拮抗剂本身并不影响睾丸血流。ET -1注射2小时后在睾丸小静脉中观察到多形核白细胞的聚集。在睾丸间质细胞、支持细胞和内皮细胞中观察到免疫反应性ET -1。hCG刺激使睾丸irET -1含量增加2倍，但局部注射ET -1拮抗剂对hCG处理的大鼠的睾丸血流没有影响。本研究表明，ET -1可能是一种受激素调节且在局部产生的睾丸血流和微循环调节剂。
