No abstract

To determine whether atrial natriuretic peptide (ANP) is a circulating hormone in the human fetus, ANP levels in umbilical cord plasma obtained at the time of delivery in 10 normal infants were measured by RIA. Plasma ANP levels were consistently higher in paired umbilical cord arterial than in cord venous samples. The mean umbilical cord arterial plasma ANP concentration [283 +/- 56 (+/- SEM) pg/ml] was significantly higher than that in cord venous plasma (165 +/- 27 pg/ml) or maternal peripheral venous plasma (155 +/- 25 pg/ml). Analyses by reverse phase high performance liquid chromatography revealed that the elution pattern of plasma ANP in cord arterial blood and that in maternal venous blood were nearly identical and that the retention time of the main ANP peak coincided with that of alpha-human ANP. These results suggest that alpha-human ANP is a circulating hormone in the human fetus.

No abstract

We report two patients with transient late neonatal hypocalcemia. Serum examination showed low calcium (Ca), high phosphorus, high parathyroid hormone (PTH), normal 25-hydroxyvitamin D and low or normal 1,25-dihydroxy vitamin D (l,25(OH) 2 vitD) levels. PTH infusion test revealed normal cyclic AMP production. In these patients, l,25(OH) 2 vitD production by PTH, or Ca mobilization from bone and Ca absorption from intestine by PTH and l,25(OH) 2 vitD might have been disturbed transiently due to developmental immaturities. This is a new type of transient late neonatal hypocalcemia with high serum PTH levels.