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To provide a systematic review of epidemiological data regarding the association between erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) in men.A research has been conducted on the Medline database using the keywords: ("erectile dysfunction" or "sexual dysfunction") and ("benign prostatic hyperplasia" or "lower urinary tract symptoms"). The eligibility of studies was defined using the PICOS method in accordance with the PRISMA statement. Cross-sectional studies and prospective cohorts assessing the association between LUTS and ED in the primary care setting or in general practice (i.e. exclusion of patients seen in outpatient urology or andrology) were included.Among 898 reports assessed, seven studies were included in this systematic review (whole cohort: 1,196,393 men). There were five cross-sectional studies and two prospective cohorts. The whole seven studies reported an association between LUTS and ED (range of odds-ratio: 1.52-4.03). Four common pathogenic mechanisms were found in the literature, all of them being somewhat related with metabolic syndrome and cardiovascular risk factors: reduced nitric oxide (NO) pathway signalling, increased RhoA-Rho kinase signalling, autonomic nervous system hyperactivity and pelvic atherosclerosis.The main limitations of this review were: a possible publication bias, the relatively low number of included studies and the lack of assessment of potential confounders such as factors related to sexual partner.The close epidemiological and pathogenic links between LUTS and ED have given rise to a new nosological entity: the erectile urogenital dysfunction, which should be assessed globally with special considerations to frequently associated comorbidities such as metabolic syndrome and cardiovascular risk factors.

The mechanisms involved in the physiology of pregnancy and in the pathophysiology of preeclampsia are still largely unknown. Prostaglandins metabolism, especially an imbalance between thromboxane A2 and prostacyclin does not appear sufficient to explain all the observed changes. Recent studies have shown that nitric oxide (NO), a vasodilating and a platelet anti-aggregating factor, could play a pivotal role in inducing hemodynamic changes during pregnancy. NO is produced in excess during pregnancy, mainly in uterine and renal vascular beds. Similarly, NO is in part responsible for the non-responsiveness of the vessels to vasoactive agents and plays a relevant role in peripheral vasodilation and in lowering systemic blood pressure. Furthermore, NO improves blood supply to the fetal-placental unit and to maternal kidneys. An impaired NO metabolism in pregnant rats induces changes similar to those observed in human preeclampsia. NO pathway represents a new approach to the physiology of pregnancy and to the pathophysiology of preeclampsia. Moreover, NO donors might be carefully proposed as new therapeutic agents in this disorder.

Dysfunctions of EDRF/L-arginine-NO pathway have been demonstrated in genetic and experimental hypertension. NO is produced through the conversion of L-arginine to L-citruline by NO synthases (NOS) which exist at least in two isoforms. The first termed constitutive (NOSc) and located in the endothelium of the vascular wall results in the basal and stimulated NO production. The second termed inducible (NOSi), which produces large amounts of NO, can be expressed in both smooth muscle and endothelial cells. The aim of the study was to examine and compare in isolated aortic rings of WKY and SHR rats, the activity of the two isoforms of endothelial NO synthases and their influence on the constrictor response induced by angiotensin II. On phenylephrine preconstricted endothelium intact aortic rings (10(-6) M, WKY = 1.2 +/- 0.04 g; SHR = 1.2 +/- 0.07 g; n = 7), carbachol (10(-5) M) induced a greater relaxation in WKY (84 +/- 2.5%) than in SHR (63 +/- 8.5%) rat. This suggests the presence of a low NOSc stimulated activity in the hypertensive strain. When the incubation period was limited to 30 min after equilibration period, L-arginine (3.10(-4) M) did not induce relaxation. When the incubation period was prolonged (180 min), L-arginine induced a relaxation (WKY = 75 +/- 8%; SHR = 58 +/- 10%; n = 7). This relaxation was not observed in a medium containing actinomycin D (10(-6) M) or after endothelium removal, indicating the induction of an endothelial NOSi in the two strains.(ABSTRACT TRUNCATED AT 250 WORDS)