Renal prostaglandins: Relationship to the development of blood pressure and concentrating capacity in pre-term and full term healthy infants

Abstract

The relationships between urinary prostaglandins (PGs)E2 and F2 alpha and the postnatal development of blood pressure and renal concentrating capacity were investigated in 14 pre-term and 32 full term healthy infants. Mean PGE2 and PGF2 alpha excretion was 18.9 and 10.1 ng/h/1.73 m2, respectively, in pre-term infant. In full term infants mean urinary PGE2 was significantly lower (13.4 ng/h/1.73 m2) and PGF2 alpha significantly higher (22.2 ng/h/1.73 m2). The decrease of the PGE2/PGF2 alpha ratio (P less than 0.001) was accompanied by an increase in blood pressure. High PGE2 levels in pre-term infants were inversely correlated with urinary cAMP excretion. A decreasing PGE2/PGF2 alpha ratio in full term infants was associated with increasing urinary osmolality. After intranasal administration of antidiuretic hormone (DDAVP) in 8 full term infants the increase in urinary osmolality and cAMP excretion was accompanied by a drop in PGE2 excretion to less than half the basal values. These findings suggests that the postnatal changes in urinary PG excretion are associated with a concomittant increase in blood pressure and in the concentrating capacity of the neonatal kidney.

Bartter’s Syndrome with Normal Chloride Reabsorption during Indomethacin Treatment

“…In children, espe cially those born prematurely, in whom the disease seems to be congenital, the renal PG hypersecretion might re present a persistence of fetal status, later intensified by kidney growth. This is supported by data indicating that urinary PG levels of prematurely born children are grea ter than those of full-term children [37,38]. Moreover, neonatal or early life Bartter's syndrome has been re ported to be associated with hydramnios, premature birth [39][40][41][42] and excessive renal PG overproduction [41]; the treatment of these children with indomethacin resulted in remarkable clinical and biochemical improvement.…”

Renal Response to Vasopressin in Premature Infants: What Is New?

“…In support of this assumption the PGE2/F2a ratio has been found to corre late inversely with urinary cAMP excretion and urine osmolality in healthy preterm and full-term neonates within 24 h of delivery [10]. Similarly there was a significant nega tive correlation between urinary PGE2 ex cretion and urine osmolality in healthy fullterm neonates on the 3rd and 5th day of life [25] and indomethacin administration to premature infants with patent ductus arte riosus produced a significant increase in urine osmolality.…”

24-h hydration status: parameters, epidemiology and recommendations

“…These values are just above the range of risk of hyperhydration. Mean Uosm in infants fed humanised formulas was 161 mosm/kg (104-257 mosm/kg) (Calcagno & Rubin, 1960;Janovsky et al, 1968;Saigal & Sinclair, 1977;Joppich et al, 1979;Manz, 1979) and in infants fed high-protein formulas 457 mosm/kg (334-658 mosm/kg) (Pratt et al, 1948;Pratt & Snyderman, 1953;Calcagno & Rubin, 1954;Janovsky et al, 1968). With regard to energy intake an infant fed mothers milk excreted 7.1 mosm per 100 kcal (Calcagno & Rubin, 1960;Manz et al, 1992), whereas an adult on a mixed diet excreted 30 mosm per 100 kcal (Höhler et al, 1994).…”