Testicular peritubular myoid cells are a target for adrenomedullin

Adrenomedullin (AM) is a recently cloned vasorelaxing peptide that belongs to the calcitonin gene related peptide family. AM inhibits the contraction of several types of smooth muscle cells and is present in the testis as wel l as in many other organs. The authors investigated whether testicular peri tubular myoid cells (PMC) possess specific receptors for AM. Binding of AM to PMC was saturable in a time-dependent manner and I-125-AM binding was ef fectively displaced by cold AM. The study documents that testicular peritub ular myoid cells are a target for adrenomedullin and suggests a role for th is peptide in the paracrine regulation of the testis.