Background: The diuretic effect of valproates and its relation to urinary potassium (K + ) and chloride (Cl -) excretion have not yet been investigated, so the aim of this study was to evaluate the influence of a single dose of sodium valproate (NaVPA) on 24-h urinary K + and Cl -excretion in young adult Wistar rats of both genders. For measurement of K + in urine, the same animals and samples as in our earlier publication were used (Pharmacology 2005 Nov, 75:111-115). The authors propose a new approach to the pathophysiological mechanisms of NaVPA effect on K + and Cl -metabolism.

Objective. To define 24-h characteristics of arterial blood pressure in healthy adolescent girls and boys; to determine gender-related differences of blood pressure, its circadian pattern. Material and methods. The 24-h blood pressure was monitored hourly in healthy girls (n=22, without no account for the menstrual cycle phase) and boys (n=22). Additionally, blood pressure of adolescent girls (n=15) was examined during different phases of their menstrual cycle (follicular, ovulation, and luteal). Blood pressure was monitored with an auto-cuff automatic outpatient blood pressure monitor. Results. Investigation showed gender-related differences in 24-h blood pressure. Study results revealed the circadian blood pressure rhythm characterized by a period of low values during nighttime and an early morning increase in both adolescent groups. Nocturnal systolic blood pressure was higher (P<0.05) in boys than in girls in all phases of their menstrual cycle. Diurnal systolic blood pressure in boys was higher than in girls in their follicular phase (P<0.05). The day and night blood pressure differed between boys and girls (P<0.05). A dipping blood pressure pattern as a decrease in mean nighttime blood pressure as compared with mean daytime blood pressure was defined: 10.02±6.7% in girls (n=22) and 13±6.3% in boys (n=22), without genderrelated differences (P>0.05). There were no differences in blood pressure dipping among girls’ groups in different menstrual cycle phases (P>0.05). Adolescent boys showed a significant positive correlation between their mean diurnal blood pressure and height (P<0.05). Conclusion. The study proved gender-related arterial blood pressure differences in healthy adolescents. The results demonstrate the gender-specific circadian blood pressure rhythm pattern in both gender groups.