title: Orally applied doxazosin disturbed testosterone homeostasis and changed the transcriptional profile of steroidogenic machinery, cAMP/cGMP signalling and adrenergic receptors in Leydig cells of adult rats.
abstract: Doxazosin (Doxa) is an α1-selective adrenergic receptor (ADR) antagonist widely used, alone or in combination, to treat high blood pressure, benign prostatic hyperplasia symptoms, and recently has been suggested as a potential drug for prostate cancer prevention/treatment. This study was designed to evaluate the effect of in vivo Doxa po-application, in clinically relevant dose, on: (i) steroidogenic machinery homeostasis; (ii) cAMP/cGMP signalling; (iii) transcription profile of ADR in Leydig cells of adult rats. The results showed that po-application of Doxa for once (1×Doxa), or for two (2×Doxa) or 10 (10×Doxa) consecutive days significantly disturbed steroidogenic machinery homeostasis in Leydig cells. Doxa po-application significantly decreased circulating luteinizing hormone and androgens levels. The level of androgens in testicular interstitial fluid and that extracted from testes obtained from 1×Doxa/2×Doxa rats decreased, although it remained unchanged in 10×Doxa rats. Similarly, the ex vivo basal androgen production followed in testes isolated from 1×Doxa/2×Doxa rats decreased, while remained unchanged in 10×Doxa rats. Differently, ex vivo testosterone production and steroidogenic capacity of Leydig cells isolated from 1×Doxa/2×Doxa rats was stimulated, while 10×Doxa had opposite effect. In the same cells, cAMP content/release showed similar stimulatory effect, but back to control level in Leydig cells of 10×Doxa. 1×Doxa/2×Doxa decreased transcripts for cAMP specific phosphodiesterases Pde7b/Pde8b, whereas 10×Doxa increased Pde4d. All types of treatment reduced the expression of genes encoding protein kinase A (PRKA) regulatory subunit (Prkar2b), whereas only 10×Doxa stimulated catalytic subunit (Prkaca). Doxa application more affected cGMP signalling: stimulated transcription of constitutive nitric oxide synthases (Nos1, Nos3) in time-dependent manner, whereas reduced inducible Nos2. 10×Doxa increased guanylyl cyclase 1 transcript and PRKG1 protein in Leydig cells. Orally applied Doxa significantly disturbed the transcriptional 'signature' of steroidogenic machinery, cAMP/cGMP signalling and ADRs and β-ADRs kinases in Leydig cells, thus giving new molecular insights into the role of cAMP/cGMP/adrenalin signalling in Leydig cells homeostasis.
authors: Reproductive Endocrinology and Signaling Group, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors: N J
authors: NJ
authors: Stojkov
authors: M M
authors: MM
authors: Janjic
authors: T S
authors: TS
authors: Kostic
authors: S A
authors: SA
authors: Andric
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D000728:Androgens / Q000097:blood; D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D054757:Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit / Q000187:drug effects / Q000235:genetics; D006152:Cyclic GMP / Q000378:metabolism*; D017292:Doxazosin / Q000008:administration & dosage / Q000494:pharmacology*; D006162:Guanylate Cyclase / Q000235:genetics; D006706:Homeostasis / Q000187:drug effects; D006973:Hypertension / Q000188:drug therapy; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism; D007986:Luteinizing Hormone / Q000097:blood / Q000187:drug effects; D008297:Male; D009924:Organ Culture Techniques; D011470:Prostatic Hyperplasia / Q000188:drug therapy; D011471:Prostatic Neoplasms / Q000188:drug therapy; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects / Q000378:metabolism*; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013256:Steroids; D013739:Testosterone / Q000097:blood*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D000728:Androgens; D054757:Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit; C517837:PRKAR2B protein, human; D011941:Receptors, Adrenergic; D018340:Receptors, Adrenergic, alpha-1; D013256:Steroids; D013739:Testosterone; D007986:Luteinizing Hormone; D000242:Cyclic AMP; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D017292:Doxazosin