Tissue kallikrein and bradykinin B₂receptors in the reproductive tract of the male rat

Abstract

The setting of a local tissue kallikrein kinin system (tKKS) within the reproductive organs of the male rat was investigated by analysing bradykinin subtype 2 receptor (B2R) gene expression and cellular distribution of B2R protein and the kinin-liberating protease tissue kallikrein (tK). Reverse transcription-polymerase chain reaction showed B2R expression in testis, epididymis and prostate from prepubertal and sexually mature rats. In mature testis, in situ hybridization and immunohistochemistry localized B2R mRNA and protein besides endothelial cells of blood vessels exclusively on pachytene spermatocytes and round and elongated spermatids. B2R expression within the seminiferous tubules was found to be dependent on the stage of the spermatogenic cycle. In pre-pubertal rat testis, B2R mRNA and protein were additionally located in peritubular cells. In the testis, specific staining for tK occurred in addition to endothelial cells of blood vessels on the acrosomal cap of round and elongated spermatids. This immunostaining was also stage-dependent. In the epididymis, tK was detected on epithelial cells near the apical surface. The stage-dependent specific expression of tK and bradykinin B2Rs in developing germ cells and peritubular cells suggests a potential role of the tKKS in the local regulation of spermatogenesis and seminiferous tubule function.

Sperm preparation for ART

“…Miska et al [191] showed that porcine pancreatic kallikrein, which is taken orally, is absorbed in unaltered form by the intestine. In the light of the recent data by Monsees et al [178-180] obtained in the rat, the kallikrein-kinin system in the male reproductive tract seems to play a role in the regulation of Sertoli cell function, the local regulation of spermatogenesis or in the function of the seminiferous tubules.…”

“…Despite all components of the kallikrein-kinin system are present in the male and female genital tract [177,178] and the localization of the bradykinin B 2 -receptor in rat testis [179,180], the function of the kallikrein-kinin system for male reproductive function is still unclear. The prostate-specific human glandular kallikrein, which is about 500-times less effective than tissue kallikrein, is present in human seminal plasma [181].…”

Transforming Growth Factor Beta 1 Induces Tight Junction Disruptions and Loss of Transepithelial Resistance Across Porcine Vas Deferens Epithelial Cells1

“…No definite evidence is yet available on whether vas deferens epithelial cells synthesize and secrete TGFB, but immunohistochemical data are available to support that epididymal epithelia do [28]. Moreover, local activation of TGFB is a key regulatory mechanism for signaling [41,42] and, interestingly, epididymal epithelia express proteases that activate TGFB [43,44]. The luminal environment of the male excurrent duct also presents segmental pH variability, which, in segments such as the cauda epididymis, reaches fairly acidic levels.…”

Pharmacological characterization of canine bradykinin receptors in prostatic culture and in isolated prostate

“…A role for kinins in the genitourinary system has been speculated upon due to the presence of prostate-specific antigen and other kallikreins (Fichtner et al, 1996;Monsees et al, 2003). Differences in the amounts of kallikreins in the prostate are being proposed as a marker to distinguish between normal, cancerous and benign prostatic hyperplasia (Scorilas et al, 2003).…”