Effect of Jaundice Phototherapy on Intestinal Mucosal Bilirubin Concentration and Lactase Activity in the Congenitally Jaundiced Gunn Rat

Summary: The effect of phototherapy on intestinal mucosal bilirubin concentration and lactase activity in the Gunn rat was studied. Ten groups of six or seven animals each were studied. Heterozygous (Ji) and homozygous (jj) animals were given 24, 48, or 72 hr of continuous phototherapy, and Jj and jj animals were given 24− and 48-hr sham control treatments. Phototherapy reduced serum billrubin concentration by 53% at 24 hr, 59% at 48 hr and 68% at 72 hr. The mucosal concentration of bilirubin appeared to parallel the declining serum concentration and was lower in treated than in control jj animals. The jejunal and ileal lactase activity, expressed per mg protein, was not depressed by phototherapy. The lactase activity of jejunum and of ileum of treated jj as compared to treated Jj and control jj at 24 and 48 hr and as compared to treated Jj at 72 hr was never reduced; i,e., jejunal lactase activity in jj treated for 72 hr was 15.1 ± 4.2 (x ± S.D.) units/g protein as compared to 16.2 ± 4.2 for Jj treated for 72 hr and 12.0 ± 4.2 for jj 48-hr control animals. The ratio of lactase to sucrase activity demonstrated a significant increase in lactase activity relative to sucrase in all animals treated for 48 or 72 hr. This latter effect is potentially due to alteration in the circadian rhythm while under constant irradiance.These data convincingly demonstrate that the Gunn rat does not develop lactase deficiency consequent to phototherapy.Speculation: These data support the hypothesis that acute intestinal secretion is important in the mechanism of diarrhea occurring during jaundice phototherapy by arguing against the role of lactase deficiency in that mechanism.

[1]  F. Ebbesen,et al.  GUT TRANSIT TIME AND LACTOSE MALABSORPTION DURING PHOTOTHERAPY , 1980, Acta paediatrica Scandinavica.

[2]  G. Odell,et al.  INCREASED OSMOTIC FRAGILITY OF ERYTHROCYTES IN CHRONICALLY JAUNDICED RATS AFTER PHOTOTHERAPY , 1979, Acta paediatrica Scandinavica.

[3]  P. Buchan Pathogenesis of neonatal hyperbilirubinaemia after induction of labour with oxytocin. , 1979, British medical journal.

[4]  A. Mcdonagh,et al.  Jaundice phototherapy: micro flow-cell photometry reveals rapid biliary response of Gunn rats to light. , 1978, Science.

[5]  G. Odell,et al.  480 SMALL BOWEL SECRETION INDUCED BY UNCONJUGATED BILIRUBIN , 1978, Pediatric Research.

[6]  M. Cohen,et al.  EFFECTS OF PHOTOTHERAPY ON INTESTINAL DISACCHARIDASE ACTIVITY IN THE RAT , 1977, Pediatric Research.

[7]  M. Thaler,et al.  Stimulation of bilirubin formation in liver of newborn rats by fasting and glucagon. , 1977, Gastroenterology.

[8]  S. Lie,et al.  22: Temporary intestinal lactase deficiency as one etiological factor of the diarrhea of light-treated Jaundiced infants , 1976, Pediatric Research.

[9]  N. Stevenson,et al.  Circadian rhythms of intestinal sucrase and glucose transport: cued by time of feeding. , 1976, The American journal of physiology.

[10]  P. Krasilnikoff,et al.  DIAGNOSTIC VALUE OF DISACCHARIDE TOLERANCE TESTS IN CHILDREN , 1975, Acta paediatrica Scandinavica.

[11]  E. John Complications of phototherapy in neonatal hyperbilirubinaemia , 1975, Australian paediatric journal.

[12]  F. Rubaltelli,et al.  EFFECT OF LIGHT EXPOSURE ON GUT TRANSIT TIME IN JAUNDICED NEWBORNS , 1973, Acta paediatrica Scandinavica.

[13]  J. Jacobsen,et al.  INFLUENCE OF PHOTOTHERAPY ON UNCONJUGATED BILIRUBIN IN DUODENAL BILE OF NEWBORN INFANTS WITH HYPERBILIRUBINEMIA A Preliminary Study , 1972, Acta paediatrica Scandinavica.

[14]  W. Oh,et al.  Phototherapy and insensible water loss in the newborn infant. , 1972, American journal of diseases of children.

[15]  J. Ostrow,et al.  Photocatabolism of labeled bilirubin in the congenitally jaundiced (Gunn) rat. , 1971, The Journal of clinical investigation.

[16]  A. Dahlqvist Assay of intestinal disaccharidases. , 1970, Analytical biochemistry.

[17]  G. Odell,et al.  Bilirubin nephropathy in the Gunn strain of rat. , 1967, The American journal of physiology.

[18]  S. Boellner,et al.  Impairment of intestinal hydrolysis of lactose in newborn infants. , 1965, Pediatrics.

[19]  C. Cori,et al.  Purification of the hyperglycemic-glycogenolytic factor from insulin and from gastric mucosa. , 1949, The Journal of biological chemistry.

[20]  K. Evelyn,et al.  THE DETERMINATION OF BILIRUBIN WITH THE PHOTOELECTRIC COLORIMETER , 1937 .