Finasteride reduces microvessel density and expression of vascular endothelial growth factor in renal tissue of diabetic rats.

BACKGROUND: Vascular endothelial growth factor (VEGF) plays a critical role in the pathogenesis of diabetic microvascular complications. Finasteride has been confirmed to decrease VEGF expression in prostate and prostatic suburethral tissue resulting in limiting hematuria from human benign prostatic hyperplasia. The purpose of this study was to evaluate the effects of finasteride on microvessel density (MVD), VEGF protein and mRNA expressions in the renal tissue of diabetic rats. METHODS: Diabetic rats induced by streptozotocin were intragastrically given finasteride at 30 mg/kg body weight once a day for 4 weeks. Histomorphologic changes in kidney were observed under light microscope. Immunohistochemistry for CD34 and VEGF on kidney sections was performed to assess MVD and VEGF protein expression in glomeruli of rats, respectively. The VEGF mRNA expression in the renal tissue was examined using reverse transcription polymerase chain reaction analysis. RESULTS: The glomerular tuft area, glomerular volume, MVD, VEGF protein expression in glomeruli and VEGF mRNA expression in the renal cortex tissue were significantly increased in diabetic rats and finasteride-treated rats when compared with controls (P < 0.01, P < 0.05). When compared with diabetic rats, the glomerular tuft area, glomerular volume, MVD, VEGF protein expression in glomeruli and VEGF mRNA expression in the renal cortex tissue of finasteride-treated rats were significantly decreased (P < 0.05, P < 0.01). CONCLUSIONS: Finasteride reduces the VEGF expression and decreases the MVD in the renal tissue of diabetic rats, suggesting the therapeutic potential of finasteride on diabetic microvascular complications.

Effects of imidazolines on neurogenic contraction in isolated urinary bladder detrusor strips from rabbit.

Moxonidine and clonidine, which are imidazoline compounds, are sympathetic modulators used as centrally acting antihypertensive drugs. Moxonidine, clonidine, and agmatine produce extensive effects in mammalian tissues via imidazoline recognition sites (or receptors) or α(2)-adrenoceptors. To investigate the effects of imidazolines on the function of the urinary bladder, we tested the effects of moxonidine, clonidine, and agmatine on the neurogenic contraction induced by electric field stimulation, and on the post-synaptic receptors in isolated urinary bladder detrusor strips from rabbit. Both moxonidine at 1.0-10.0 µmol/L and clonidine at 0.1-10.0 µmol/L inhibited electric-field-stimulation-induced contraction in a concentration-dependent manner, but not agmatine (10.0-1000.0 µmol/L). Both moxonidine and clonidine failed to affect carbachol or adenosine-triphosphate-induced contractions; however, 1000.0 µmol/L agmatine significantly increased these contractions. Our study indicates that (i) moxonidine and clonidine produce a concentration-dependent inhibition of the neurogenic contractile responses to electric field stimulation in isolated detrusor strips from male New Zealand rabbits; (ii) post-synaptic muscarinic receptor and purinergic receptor stimulation are not involved in the responses of moxinidine and clonidine in this study; (iii) the inhibitory effects of these agents are probably not mediated by presynaptic imidazoline receptors.

Effects of (-)doxazosin on histomorphologic and cell apoptotic changes of the hyperplastic prostate in castrated rats.

BACKGROUND: (-)Doxazosin is one of the enantiomers of (+/-)doxazosin, and it was reported that (-)doxazosin possessed higher selectivity for lower urinary tract between the cardiovascular system and the urinary system in the animal experiments in comparison with that of (+/-)doxazosin and (+)doxazosin. Therefore, it is important to know whether (-)doxazosin has a therapeutic effect on the hyperplastic prostate. METHODS: (-)Doxazosin and (+/-)doxazosin were administered intragastrically to prostatic hyperplasia rats, induced by testosterone propionate for 4 weeks, and each experimental group contained 8 animals. The histomorphologic changes of the prostate were observed under light microscope, the quantitative analysis of the prostatic glandular cavity was performed using an image analysis system, and the cell apoptosis was detected by using flow cytometry. RESULTS: In comparison with model-control group, the volume index of the prostate in (-)doxazosin 3.0 mg/kg group became significantly smaller. The maximal diameter, perimeter, and area of the hyperplastic prostate glandular cavity, and the glandular epithelial cell height in (-)doxazosin (0.3, 1.0, and 3.0 mg/kg) groups and (+/-)doxazosin group were significantly reduced. (-)Doxazosin and (+/-)doxazosin did not significantly affect cell cycle distribution and cell proliferation index of the hyperplastic prostate. However, apoptotic rates of the prostatic cells in (-)doxazosin (0.3, 1.0, and 3.0 mg/kg) groups and (+/-)doxazosin group were significantly increased in comparison with those of model-control group. CONCLUSIONS: Both (-)doxazosin and (+/-)doxazosin inhibit the prostatic hyperplasia induced by testosterone propionate in castrated rats. The induction of prostate cell apoptosis might be one of the mechanisms underlying the therapeutic role of (-)doxazosin.