Human Fetal Insulin Secretion in Response to Maternal Glucose and Leucine Administration

Abstract

Departments OF Hmtbld Anatomy. O b r t c t r i c r and Gynmcology 11".and P e d i a t r i c s . U n l v e r a i c y ot h t a n l a , Cmtmnla, t t r l g . M a t r r n a l and l e t m l serum i n~u l i n r t s p o n s r t o g l u t o~~. ImucIno and l e u c i n e p l u s glucose uma oxamtncd by I n f u a l o n e t o n a t w l prcg,runt -m e n a t term l m cd l a r @ I r b e f o r e calmrean r e c t l o n . The ~t a m . 1 Lnfumlon o i s l u c o s t (M 8 ) f o r 30 m r 60 minutes vaa asmocinted w i t h rmrkad hypaqlycomi. m d u l t h n r l t e I n r e r v a I n m u l i n i n m t k e r and f~t u . . Thm f e r a l Lnawlln reaponme t o t h e admin l s t r a t l o n o f g1uto.c f o r 60 minutea was h i g h e r Ip+O.OlS t h a n when the maat dose war g l v r n t o r 30 minutes. u h l l m r h e b l o o d g l u c n r e urns Lorsr (14 0.01).The m a t e r n a l i e t u s i o n o t a r m l l e r dose o f glucose 125 g ) et Leuclne 0 5 g) t o r 40 minute# productd an increane ill sti n r u 1 L n o n l y ln t h e w r h e r s .Houever the almultanrous ~d n i n i s t r * t t o n o f these aubrtanccs s t i m u l a t e d r u r c rn a l and f e t a l L n a u l i n accretion. Tha f e t a l l n r u l l n l e v a 1 produced war a i m l l~r t o t h n t a c r n a f t e r the n r t e r~l l n f u s i o n o r 50 g ~f glucose t o r f.0 ~i e u t t s .v h l l s t h e c o r d b i o o d ~l u c o r e wan r l l g h t l y h l g h e r b u t m l g n i l i c s n t l q d t t l e r e n t (pd0.01) than r h a r e r s n I n t h e r a l t n c lntuaed group.I t 1 1 swg8aatcd tbt amino mcidr u l t h glucome r t s u l r t e f c t m l L n s u l l n metret i a n .C l u c o s t r a p i d l y c r e r l e a t h c pl#ranrm I n t h e prssenca o l a concentration g r a d l e n t betvcen mthmr and f e t u s and i t has bean s u g e e t t d rhst f e t a l plasma g l u c o r e is c o n t r o l l e d i n d i r e c t l y v i a t h e u t m m m l c n d o c r l n * #yetem (31. Inau-I I n i r preeent I n t h e f e t a l pancreas as e a r l y aa zhe 1 0 t h g c a t s t l o n s l week and i n l t t m l p l u s s Irm t h e 1 2 t h vemk (15. 11. 201. The ImmulIn l a o f i e t m l o r lg i n sinc. t h e hursle plntentm i s e i t h e r I m p e m a b l e o r t h e amount ~r a n a f t r r t di s p h y a i o l~~l c a l l y inmignLficmnt (18). Houauer. l l s t l e I n f o m t i o n i s c v a i l ab l e r c g m r d l n~ t h e development of thm m e f h a n l~n s t h t c o n t r o l I t s s e f r r t l o n by t h e feral bee4 c e l l * o r i t s p h y a i o l g l c a l eftectm. S t u d l e r hauc decmnstrattd t h t e a r l y I n 8c.tation (12 t o 20 wtcka) t e t m l L n r u l t n r t r p o n s a r o u t e r n m l b y p a r g l y c c a l a l a n e g l e g l b l c (15). By t e n t h e l e f u l i n u t e r o 14 cmpable af r e a p o d I n a t o ~t e r n m l hypcrglycemia w i t h a n e l t v a r l o n -I s a r m 1nmulin.though t h e renponaes a r e mttenuatmd coaparrd w l r h chote o f a d u l t 5 (151.Tha o b j e c t o f t h e p r e r s n c ntudy 1s co p r o v i d e evidence t h a t soae anln...

Inhibition of Glucagon Secretion in the Human Newborn by Glucose Infusion

“…18 In our study the insulin response to glucose was variable, but in most of the subjects examined insulin increased gradually with a peak at 60 and 90 min. Similar findings have been described by several authors in fetuses at term in response to maternal administration of glucose 19 and in newborn infants. 20 Gentz et al 21 observed that insulin response as measured in the peripheral plasma is extremely variable in low-birth-weight infants and cannot be used to explain the removal rate of plasma glucose.…”

Arterial Hypoxemia and Hyperinsulinemia in the Chronically Hyperglycemic Fetal Lamb

“…Fetal insulin secretion, although quantitatively and qualitatively different from the adult (20), does occur after an appropriate glucose stimulus in a variety of species (8,15,20). Hyperglycemia in the present preparations was generally associated with a modest but variable increase in plasma insulin concentration.…”

Effect of maternal intrapartum glucose therapy on neonatal blood glucose levels and neurobehavioral status of hypoglycemic term newborn infants

“…An alteration in the normal circulating levels of one or both of these hormones in the immediate postnatal period may greatly hamper the metabolic adaptation [13]. Maternal glucose infusion by raising maternal blood glucose level facilitates diffusion of higher amounts of glucose across the placenta to the fetus and causes fetal hyperglycemia [2,5,17, 24] which in turn stimulates fetal insulin [2,9] and inhibits glucagon secretion [10]. Thus a significant increase in fetal/cord plasma insulin [4,11,15] and decrease in glucagon levels [3,11] occurs.…”