1210 Glucose-Lactate Relation in the Human Newborn

Abstract

We studied 125~-insulin total and non-specific binding(1B) and 3~-deoxyglucose uptake (Gu) by 30d isolated fetal rabbit-brain cells (viability of >93%;n=8), to define the significance of the IR in the fetal brain. IB and Gu by brain cells were also assessed in the presence of lOmM phenylarsine oxide (PA) (n=4; prevents IR internalization) and 10vM chloroquin (CQ) (n=5; a lysosomotropic agent), to study the internalization and intracellular degradation of the IR (extracellular degradation was constant throughout the study). Peak specific IB per 6 . 4~1 0~ cells was achieved by 1-3 min (2.74+0.18%, X S E M ) , declining by 20 min (0.48+0.15;p<0.001). A decrease in the peak binding was observed with PA (0.40f0.08;p~0.001), whereas CQ resulted in a peak IB of 1.32+0.19, with no decline in IB at 20 min (2.11+0.49;p<0.01). 1x10=~11 insulin increased the Gu from 0.03+0.002to 0.05fP03nM/ 6 . 4~1 0~ cells (p<0.01). PA inhibited Gu and the insulin induced increase in Gu by the brain cells, while CQ inhibited the insulin induced increase in Gu alone (0.02+0.0007;p~0.01). Summary: 1)In the presence of PA, IB is decreased 2)CQ delayed the decline in peak IB secondary to its lysosomotropic effects and decreased intracellular IR degradation 2)Insulin augmented Gu by fetal brain cells 4)Inhibition of IR internalization by PA or lysosomotropic effects by CQ interfered with the insulin induced Gu by the brain cells. We conclude that the insulin induced Gu by fetal brain cells is associated with internalization of the IR. GALACTOSE-I-PHOSPHATE URIDYL TRANSFERASE SCREENING.1208 Chandradhar Dwivedi and Saburo Hara (Spon. by Festus 0. Adebonojo) D e p a r t m e n t -P e d i a t r i c s , Meharry Medical Coll ege, Nashvi 1 l e , TN. 37208Galactose-1-phosphate uridlytransferase (Gal-1-PUT) deficiency i s an inborn e r r o r of metabolism transmitted as an autosomal recessive t r a i t . Gal-1-PUT Screening was performed in a l l the newborns delivered a t Hubbard Hospital of Meharry Medical College f o r an e a r l y detection of t h i s deficiency. The appearance of fluorescent NADPH a f t e r incubating the blood spot with Gal-1-P, UOPG and NADP was used a s a screening t e s t . 2134 newborns were screened during May 1979-Sept. 1984. Three abnormal t e s t s were detected i n i t i a l y . After repeating the screening t e s t and quantitating the Gal-1-PUT, one case of t h i s deficiency was established. Two f a l s e positives were presumably due t o i n s u f f i c i e n t blood on the spot. This p a t i e n t i s a f u l l term f i r s t born male t o a Black mother. Gal-1-PUT was quantitated i n erythrocytes by UDPG consumption t e s t . The p a t i e n t had 1.6 u n i t s of a c t i v i t y , however, mother and her brother had 10.7 and 6.4 units respectively. U t i l i z a t i o n of one micromole of UDPG per gram hemoglobin per hour i s defined a s one u n i t . Patient was placed on modified galactose f r e e d i e t and successfully t r e a t e d . His growth and development a r e within normal l i m i t s f o r h i s age....