THE DEVELOPMENT OF CELLULAR IMMUNITY TO STREPTOCOCCUS THE EFFECTS OF EXOGENOUS GLUCAGON ON FETAL METABO-

287 Haya R. Rubin and Ricardo U. Sorensen, Case'Western

Reserve University, Rainbow Babies & Childrens Hospi-
2Yu LISM IN THE SHEEP. Richard L. Schreiner, James A.
Lemons, Helen Moorehead, Rick Bohnke, Debra Reyman.
tal, Departments of pediatrics and Pathology, Cleveland. (Spon. by Jerry Bergstein), Indiana University School of Medi-
The role of antigenic exposure in the development of cellular cine, Indiana University Hospitals, Department of Pediatrics,
immunity to bacteria was evaluated analyzing the responses of Indianapolis.
neonatal and adult lymphocytes to two streptococcal antigen pre- The effect of exogenous glucagon on fetal and maternal glu-
parations. Responses to the soluble antigen SK-SD were analyzed cose, fructose, insulin and glucagon concentrations was studied
in diluted whole blood cultures (WB) and in ficoll-hypaque sepa- in the chronic fetal sheep model. Eight near-term fetuses were
rated mononuclear cells (MNC) from peripheral blood in adults infused with glucagon (40 nglmin) for 60 min via a fetal femoral
(PBL) or cord blood (CBL). Responses to whole cell, killed strep- vein catheter. Fetal plasma glucagon increased from 37.66'7.86
tococcus group A, and group B I and B 111 strains were analyzed (SEM) to 420.50'38.59 pglml (p<.001) within 15 rnin of beginning
with MNC only. Results of proliferative responses were assessed the infusion, reaching 531.80f117.54 pglml (p<.001) by 60 rnin
by 3H-thymidine incorporation, and expressed as mean counts per and returning to the baseline level 60 rnin after stopping the
minute over background for triplicate cultures (net cpm). infusion. Fetal arterial glucose increased from 12.0650.84 to
Strep-A 15.50'0.68 mg % (p<.0001) after 15 min of infusion (p<.001),
Neonates 1922 0 Results in the table show that both and reached a maximum level of 17.18f0.94 mg % by 60 rnin
Adults 4099 6917 newborns and adults responded to killed (p<.001). Fetal arterial plasma insulin was significantly in-
strep A. (Similar results were found creased within 60 rnin of infusion (16.45'3.73 to 29.38'4.41
for strep. B I and B 111.) In contrast, only adults responded uU/ml, p<.001). Fetal fructose did not change. During the 60
to SK-SD in WB (shown in table) or MNC. Normal newborns had no rnin infusion and postinfusion period, there were no changes in
responses over background to this antigen. Yet, lymphocytes from the maternal concentrations.
a newborn with strep A sepsis had a response of 7152 net cpm to These results, in addition to our previous studies demon-
SK-SD. This indicates that newborns can develop a strong SK-SD strating an increase in fetal glucagon concentration with pro-
response with exposure, but otherwise do not respond. longed maternal fasting, provide further evidence that glucagon
Neonatal lymphocytes do respond to all strains of killed strep. is an important regulator of fetal metabolism.
tested, without known prior exposure. This may reflect a pathway
of cellular immunity to non-specific bacterial components, active
before antigen-dependent responses develop.

FETAL HEPATIC VENOUS OXYGEN SATURATION AND LIVER

288 OXYGENATION. Abraham M. Rudolph and James Bristow.
Univ. Calif., Cardiovasc. Res. Inst., San Francisco.
291 DEVELOPMENT OF BETA-ADRENERGIC RECEPTORS I N FETAL RAT

School o f Med.. Strona Mem . Hosa ,D e ~ t . o f Peds. Roch. NY

LUNG,HEART,AND BRAIN TISSUE.Donald L.Shapiro,U.of Roch
Previously we showed that the left lobe of the fetal liver in Beta-adrenergic c e l l membrane-receptors were s t u d i e d i n mem-
fetal lambs receives highly saturated 02 umbilical venous (W) brane f r a c t i o n s prepared from developing r a t lung, heart, and
but no poorly saturated portal venous (PV) blood. Total left lobe b r a i n t i s s u e s . Receptors were i d e n t i f i e d u s i n g r a d i o l a b e l e d ( 3 ~ )
flow is 350 ml/min/lOOg, whilst the right lobe flow is 500ml/min/ d i h y d r o a l p r e n o l o l (DHA), a beta-adrenergic a n t a g o n i s t w i t h h i g h
lOOg and it receives PV and UV blood. To assess whether the a f f i n i t y f o r r e c e p t o r s i t e s . Developmental p r o f i l e s from 19 days
differing blood 02 sats entering the two lobes affect oxygenation, g e s t a t i o n t o 24 hours a f t e r b i r t h (TABLE) showed no s i g n i f i c i a n t
we developed methods for chronic cannulation of the hepatic venous i n c r e a s e i n t h e amounts o f beta-adrenergic r e c e p t o r s i n b r a i n
veins (HV) in fetal lambs. The left and right HV join the tissue. I n h e a r t t i s s u e , an i n c r e a s e occurred between 19 and 20
inferior vena cava (IVC) anteriorly just below the diaphragm; days g e s t a t i o n . I n l u n g t i s s u e , t h e r e was a marked i n c r e a s e i n
they were cannulated through pursestring sutures in the thoracic r e c e p t o r s between 20 and 21 days g e s t a t i o n . T h i s c o i n c i d e s w i t h
IVC through right thoracotomy. In 24 fetal lambs (116-122 d) we m a t u r a t i o n o f t h e pulmonary s u r f a c t a n t system, and i t i s specula-
placed catheters in L or R HV, PV, IVC, and descending aorta (AO). ted t h a t the increase i n lung receptors i s associated w i t h type
The 02 sat in the LHV was higher than that in RHV; it was close I 1 pneumocytes which a r e known t o have beta-adrenergic r e c e p t o r s .
to W 02 sat, but RHV 02 sat was similar to that in AO.
02 sats (percent) were:
A O U V H V IVC pmoles DHA boundlmg t i s s u e ( f S.E.)
Left HV (n5) 55.2'6.4 79.629.9 67.4'8.0 32.2'6.6
Right HV (1113) 57.9'10.8 80.8'8.1 60.0f10.5 36.0'8.3
Blood flows to the R and L lobes of the liver from hepatic artery,
W , and PV were measured with radioactive microspheres and,
together with 02 content in various vessels, we showed that
oxygen consumption in m1/100g/min were similar in left (3.4) and
right (3.9) lobes of the liver. The different 02 sats in L and
R HV could be important in determining oxygen supply to various
fetal organs. de~endinaon distribution of L and R HV blood.
(supported b; NIH granEs HL 06285 and HL 24056.)

ADIPOSE TISSUE COMPOSITION -

RELATIONSHIP TO EFFECTS OF ACUTE SALT LOADING ON BLOOD PRESSURE
289 DIET. David Schiff, George Chan, University
of Alberta, Edmonton.
292 REGULATION I N THE NEWBORN LAMB. Sharon R. S i e g e l ,
UCLA Div. o f Nephroloav, Los Anaeles, C a l i f o r n i a .
Human breast milk (EBM), Similac(SlM), SMA, and In- The normal newborn has an' impaired c o n s e r i a t i o n o f sodium;
tralipid (IL) vary in their fatty acid composition. h i g h r e n i n - a n g i o t e n s i n system (RAS) l e v e l s ; and a decreased
This study reports on the effect of dietary fat on the pressor responsiveness t o a n g i o t e n s i n 11(A-11). The purpose o f
composition of adipose tissue in infants during the t h i s study was t o determine whether i n c r e a s i n g t h e newborn s a l t
first 3 months of life. 1 8 infants ranging in age from i n t a k e would suppress t h e h i g h RAS l e v e l s and a l t e r blood pres-
1 day to 3 months and requiring surgery were studied. sure(BP) responsiveness. I n Exper 1, 8 newborn lambs were i n f u s e d
Subcutaneous adipose tissue was obtained from the inci- w i t h NaCl 1 0 mEq/kg i n 20 m l l k g 5%D/W over 60 min, f o l l o w e d by
sion site and analyzed for fatty acids. Fatty acid com s e r i a l doses o f A-11 (0.025, 0.5, 0.1, and 0.25 ug/kg/min), each
position of the diet and adipose tissue are as follows: f o r 15 min. Mean a o r t i c BP was monitored c o n t i n u o u s l y . I n Exper 2
Formula Fatty Acid Composition % Total (0.25 u g l k g l m i n ) was i n f u s e d i n t o 5 newborn lambs a f t e r a s i m i l a r
C12:O C14:O C16:O C18.0 C18:l C18:2 NaCl l o a d i n g . Plasma r e n i n a c t i v i t y (PRA) was measured b e f o r e and
EBM 7.7 12.7 25.0 9.6 33.0 5.0 a t 5, 15, and 30 min o f t h e A-11 i n f u s i o n . I n Exper 1, A-11
SIM 11.3 11.0 12.5 4.5 21.3 38.4 (0.025 u g l k g l m i n ) increased BP 30 mm Hg i n t h e ewe, caused no
SMA 7.4 6.1 14.4 8.1 43.9 18.2 change i n t h e c o n t r o l newborn, and increased BP 15 mm Hg i n t h e
IL 11.0 4.5 26.0 49.6 volume expanded newborn; (0.25 u g l k g l m i n ) increased BP 30 mm Hg
Adipose Tissue Fatty Acids % Total i n t h e c o n t r o l newborn and 40 mm Hg i n t h e volume expanded new-
NO. Diet Duration C14:O C16:O C16:l C18:O C18:l C18:2 born. I n Exper 2, PRA decreased from 22.1 + 2.1 n g l m l l h r (M and
6 NPO 1 d 3.2 45.9 12.8 3.5 29.7 2.7 SEM) t o 10.8 + 2.1 (p<.05) a f t e r t h e volume expansion alone, and
2 EBM 12 d 4.1 31.0 9.6 5.7 42.0 6.2 t o 5.2 + 1 .O Tpc.05) a f t e r 30 m i n o f t h e A-11 i n f u s i o n . BP
3 SIM 16 d 5.1 30.8 10.7 3.1 32.4 13.6 decreasFd 10 mrn Hg a f t e r t h e s a l t l o a d i n g alone. I n c o n c l u s i o n :
1 SMA 3 M 3.2 14.7 2.7 4.7 60.1 12.2 Acute s a l t loading, 1 ) increases t h e pressor responsiveness t o
2 IL 20 d 3.0 39.0 10.0 4.1 32.9 9.5 A-11; 2) suppresses t h e r e n i n - a n g i o t e n s i n system; and 3 ) de-
4.4 22.0 5.0 3.8 33.6 23.3 creases basal BP i n t h e newborn lamb. Therefore, t h e r e n i n -
IL
SIM ) 2
: i
This study shows that diet can alter an infant's adi-
a n g i o t e n s i n system c o n t r o l o f BP and A-11 responsiveness may
be r e l a t e d t o t h e newborn sodium s t a t e .
pose tissue composition in a short time.