We have demonstrated that central administration of zinc in minute amounts induces a significant antidipsogenic action in dehydrated rats as well as in rats under central cholinergic and angiotensinergic stimulation. Here we show that acute third ventricle injections of zinc also block water intake induced by central ß-adrenergic stimulation in Wistar rats (190-250 g). Central inhibition of opioid pathways by naloxone reverses the zinc-induced antidipsogenic effect in dehydrated rats. After 120 min, rats receiving third ventricle injections of isoproterenol (160 nmol/rat) exhibited a significant increase in water intake (5.78 ± 0.54 ml/100 g body weight) compared to saline-treated controls (0.15 ± 0.07 ml/100 g body weight). Pretreatment with zinc (3.0, 30.0 and 300.0 pmol/rat, 45 min before isoproterenol injection) blocked water intake in a dose-dependent way. At the highest dose employed a complete blockade was demonstrable (0.54 ± 0.2 ml/100 g body weight). After 120 min, control (NaAc-treated) dehydrated rats, as expected, exhibited a high water intake (7.36 ± 0.39 ml/100 g body weight). Central administration of zinc blocked this response (2.5 ± 0.77 ml/100 g body weight). Naloxone pretreatment (82.5 nmol/ rat, 30 min before zinc administration) reverted the water intake to the high levels observed in zinc-free dehydrated animals (7.04 ± 0.56 ml/ 100 g body weight). These data indicate that zinc is able to block water intake induced by central ß-adrenergic stimulation and that zincinduced blockade of water intake in dehydrated rats may be, at least in part, due to stimulation of central opioid peptides. Correspondence

Introduction: Lower urinary tract dysfunction (LUTD) is a common clinical condition. Emotional and behavioral issues are increasing among children and adolescents, with stress indicating diffi culties in personal and social functioning. This study evaluated whether urinary tract symptoms (LUTS) is associated with stress. Materials and Methods: A cross-sectional, analytical study with 6-14-year-old patients with LUTS and no anatomical/neurogenic urinary tract abnormalities was conducted using the Dysfunctional Voiding Scoring System, a psychological assessment and the Child Stress Scale. The overall stress score was analyzed in relation to the psychological assessment data. Answers to the seven specifi c DVSS urinary questions were compared with those for the four Child Stress Scale domains. Univariate and multivariate analyses were performed. The chi-square test and Pearson's correlation were used to determine associations. Signifi cance was defi ned as p <0.05. Results: Most children were male (56%). Mean age was 9.0±2.25 years. Stress was detected in 20 out of 98 patients (20.4%; 95% CI: 13-30%).Of these, 90% were born from unplanned pregnancies and 67% were upset about their disorder. All the Child Stress Scale domains were signifi cantly associated with urinary dysfunction, with dysuria being signifi cantly associated with all four domains. In the multivariate analysis, dysuria was the only symptom that remained associated with stress. Associations with stress strengthened as the frequency of dysuria increased: physical reactions (p <0.01), emotional reactions (p <0.05), psychological reactions with a depressive component (p <0.01) and psychophysiological reactions (p <0.05). Conclusion: Stress levels are higher in children and adolescents with LUTS who have more severe symptoms. Dysuria was the symptom most associated with stress, both in the physical reactions domain, in the psychological reactions domains with or without a depressive component and in the psychophysiological reactions domain.

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We have demonstrated that acute third ventricle injections of lead acetate (PbAc) exert a powerful antidipsogenic effect and induce a significant increase in renal sodium excretion. In the present study we confirm the antidipsogenic effect of lead and demonstrate that central administration of this metal, in minute amounts, significantly reduces salt intake both during dehydration and after central angiotensinergic stimulation. Adult male Wistar rats had the third ventricle cannulated seven days before the experiments. During this period they had free access to distilled water and hypertonic saline solution (1.5%). After a 24-h period of fluid deprivation, experimental animals received third ventricle injections of PbAc (0.3, N = 8 and 3.0 nmol/rat, N = 14) while controls received sodium acetate (NaAc; 3.0 nmol/rat, N = 10). Rats treated with PbAc at the highest dose showed a significant reduction (P<0.05) both in water and hypertonic saline intake when compared to controls. When the effect of lead administration on angiotensin II-induced water and salt intake was studied, normohydrated animals received third ventricle injections of angiotensin II (9.6 nmol/rat) after pretreatment with 3.0 nmol/rat of PbAc (experimental group, N = 10) or NaAc (controls, N = 8). The group pretreated with PbAc presented a significant reduction (P<0.05) in both water and salt intake compared to controls. Thus, this study confirms the antidipsogenic effect of central lead injections and demonstrates that the presence of lead in the brain exerts a significant inhibition of sodium appetite. Correspondence