Pituitary adenylate cyclase activating polypeptide (PACAP) can cross the vascular component of the blood-testis barrier in the mouse.

摘要: Pituitary adenylate cyclase activating polypeptide (PACAP), present in highest concentrations the hypothalamus and testes, affects release of LH, FSH, prolactin, as well Sertoli cell function. We examined ability 38-amino acid form PACAP labeled with 125I (I-P38) to cross vascular component blood-testis barrier. The unidirectional influx constant (Ki) was 4.23 x 10(-3) ml/g-minute, which is about 5 times faster than entry LH 17 that serum albumin. Entry occurred part by a saturable transport system, 20 micrograms/mouse unlabeled P38 inhibiting 40%. An analog peptide T, like related vasoactive intestinal has been found have its own system into brain, did not alter uptake I-P38 testes. A dose 10 micrograms/mouse, but associated contraction space HPLC confirmed small persistent percentage radioactivity recovered from testes represented intact I-P38. These results suggest circulating may contribute testicular pool PACAP, play an active role function