title: Renin, kallikrein and prostaglandin renal systems in normotensive boys with and without a family history of essential hypertension.
abstract: BACKGROUND
  The role of the kidney in the development of essential hypertension is subject of debate.
  
  
  METHODS
  We compared the renin, kallikrein and prostaglandin renal systems in two groups of normotensive boys, aged 7-16 years, with different degrees of risk for future hypertension: 27 had parents with essential hypertension and 12 had normotensive parents. Supine, standing and post-exercise plasma renin activity as well as levels of urinary kallikrein and prostaglandin E2 before and after exercise were measured.
  
  
  RESULTS
  The ratio of post-exercise plasma renin activity (ng/ml/h) to 24 h urinary sodium excretion (mEq/kg/day) was lower in children with hypertensive parents (mean +/- SEM 1.86 +/- 0.24 compared with 3.62 +/- 0.94, P = 0.02). The boys with hypertensive parents had a lower ratio of urinary kallikrein to creatinine before (0.70 +/- 0.13 compared with 1.54 +/- 0.36, P = 0.01) and after exercise (0.80 +/- 0.13 compared with 1.35 +/- 0.23, P = 0.03). The ratio of urinary prostaglandin E2 to creatinine levels did not differ between the groups before or after exercise.
  
  
  CONCLUSIONS
  The plasma renin activity response to exercise and urinary kallikrein excretion were decreased in boys at increased risk of future essential hypertension. These early abnormalities in the renin and kallikrein renal systems may be associated with the development of essential hypertension.
authors.affiliation: Section of Paediatric Nephrology, Hospital Central de Asturias and Medical School, University of Oviedo, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Rey
authors.forename: F
authors.initials: F
authors.lastname: Santos
authors.forename: S
authors.initials: S
authors.lastname: Málaga
authors.forename: G
authors.initials: G
authors.lastname: Orejas
authors.forename: M
authors.initials: M
authors.lastname: Simarro
authors.forename: M
authors.initials: M
authors.lastname: Crespo
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D016022:Case-Control Studies; D002648:Child; D003404:Creatinine / Q000097:blood / Q000652:urine; D015232:Dinoprostone / Q000652:urine*; D004198:Disease Susceptibility; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000235:genetics*; D007610:Kallikreins / Q000652:urine*; D007668:Kidney / Q000378:metabolism*; D008297:Male; D005082:Physical Exertion; D011187:Posture; D012083:Renin / Q000097:blood*; D012307:Risk Factors; D012964:Sodium / Q000652:urine; D016683:Supine Position
chemical_list: D012964:Sodium; D003404:Creatinine; D007610:Kallikreins; D012083:Renin; D015232:Dinoprostone