Search PubMed⌕ Search

Biomedical subjects

C J Cha

Publications and source records attributed to C J Cha.

At least 37 records · Page 2Linked to original sources
PubMed1987

Accelerated growth and abnormal glucose tolerance in young female rats exposed to fetal hyperinsulinemia.

This study was designed to evaluate the relationship between fetal macrosomia and postnatal growth as well as the glucose homeostasis in young female rats. We produced fetal macrosomia by fetal insulin injection at 20 1/2 days of gestation. The control subjects were injected with saline. The weights were recorded weekly from birth up to 12 wk. Only the female rats were studied. At 4, 6, 10, and 12 wk of age, oral glucose tolerance tests were performed. Also, at wk 6, 10, and 12, peri-renal-ovarian-salpingeal fat weights, the RNA, DNA, and protein contents of the abdominal muscle were determined. One-hundred seventeen control and 78 macrosomic rats were studied. The macrosomic rats showed a higher body weight (10-12%) than the control rats from birth up to 8 wk, but at 10 and 12 wk their weights were similar. The fat weights reflected the body weights, i.e. a higher fat weight in the macrosomic rats during the period of accelerated growth (from birth up to 8 wk), and a similar fat weight when the body weight of the two groups were similar at 10 and 12 wk. At 4 and 6 wk of age, the plasma glucose level measured in response to the oral glucose loading were similar in both groups. However, at 10 and 12 wk of age, the macrosomic rats had significantly higher fasting plasma glucose levels and exhibited consistently higher plasma glucose levels for the 3.5-h period of postglucose administration compared to the control rats. The plasma insulin levels rose significantly following glucose challenge. However, the values were similar in both groups at 10 and 12 wk.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Effect of respiratory acidosis on glucose homeostasis in experimental intrauterine growth retardation in rats.

Hypoglycemia and asphyxia account for a significant proportion of morbidity in the infant with intrauterine growth retardation (IUGR). The purpose of this study was to evaluate changes in glucose homeostasis in IUGR rats during acute respiratory acidosis. IUGR was produced by bilateral uterine artery ligation at 17 days of gestation in 14 pregnant rats with 23 successfully delivered pups. The normal pups (n = 31) were those whose mothers were sham operated at the same gestational period. The IUGR and normal pups were studied at 2 days of age. One group of pups was studied under room air while another was subjected to 20 min of exposure to a gas mixture of 10% O2/15% CO2, balanced with N2. Gluconeogenesis in the liver and carcass, as well as plasma glucose and catecholamines were determined before and after the exposure to the gas mixture. The results showed that the 2-day-old IUGR rats have lower body weight (P less than 0.001), liver weight (P less than 0.001), plasma glucose (P less than 0.001), and rate of gluconeogenesis (P less than 0.01) when compared with the normally grown rats. During respiratory acidosis, the normally grown rats showed an increase in plasma epinephrine (P less than 0.005) without significant change in plasma glucose and rate of gluconeogenesis. The IUGR rats on the other hand, demonstrated a decrease in rate of gluconeogenesis (P less than 0.02), an increase in plasma glucose (P less than 0.001) while the plasma epinephrine level remained unchanged. We speculate that respiratory acidosis blunted cellular metabolism in the IUGR rat resulting in decreased peripheral glucose utilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis, Respiratory↗
PubMed1986

Growth and fatty acid metabolism in experimental intrauterine growth retardation: effect of postnatal nutrition in rat.

Rats, 3 1/2 to 4 d of age, were used to study weight gain and fatty acid (FA) metabolism as a function of degree of intrauterine growth retardation (IUGR) and of postnatal nutrition. The IUGR, quantified postnatally as mild and severe, was produced by uterine artery ligation on d 17 of gestation, and controls were shamoperated. Food intake was manipulated by varying the litter size; i.e., pup number per dam was 4 or 5 for overfeeding, 8-10 for normal feeding and 13-15 for underfeeding. Fatty acid synthesis rate (FASR) (determined by tritiated water incorporation in FA) and contents were determined in selected organs at 84 to 96 h of age. The initial weights (grams) at 2 to 12 h of age were: 5.88 +/- 0.74 (mean +/- SD) for controls, 5.18 +/- 0.11 for mild IUGR and 4.18 +/- 0.24 for severe IUGR. During the first 96 h of life, weight gain was less in underfed control pups while overfeeding resulted in the same weight gain as in normally fed pups. Pups with mild IUGR showed the same effect of under- or overfeeding as control pups. In the severe IUGR groups, weight gains were similar in all three feeding groups. In the carcass, the fatty acid content was reduced as a result of both prenatal and postnatal undernutrition. Although the underfed control group had a high FASR, underfeeding had no effect on the FASR of groups with IUGR. In the liver, the FA content was also lower in the underfed controls and in IUGR groups, without any difference in FASR. Feeding did not influence the FASR of liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Relationships among maternal and fetal amino acid blood concentrations and amniotic fluid amino acid levels in pregnant rhesus monkeys.

This study was designed to explore relationships among maternal and fetal amino acid blood concentrations and amniotic fluid amino acid levels in pregnant rhesus monkeys. Although there was no constant pattern for all amino acids in the three body fluids, we observed specific patterns for most neutral amino acids, imino acids, and acidic amino acids relative to their concentrations in maternal blood, fetal blood, and amniotic fluid. Moreover, there was no correlation between fetal phenylalanine blood levels and phenylalanine concentrations in amniotic fluid indicating that amniotic fluid phenylalanine levels would not be useful to monitor fetal phenylalanine blood concentrations during pregnancy.

Amino Acids↗
PubMed1985

Cell solute composition and potassium effects in slices of the rectal gland of the dogfish shark (Squalus acanthias).

Cell solute composition and apparent intracellular ionic concentrations (subscript i) were determined in rectal gland slices of the dogfish shark (Squalus acanthias). On aerobic incubation in elasmobranch Ringer's at 15 degrees C, the steady state values were: Ki+, 151 mM, close to its apparent electrochemical equilibrium; Cai2+, 1.7 mM; Mgi2+, 7.5 mM; Cl1-, 97 mM (maintained against its electrochemical potential gradient); the sum (Nai+ + Ki+) was about 66 meq/kg cell water lower than in the medium. Of free amino acids, only the effectively impermeable anionic taurine (32 mM) and glutamate (3.7 mM) significantly contribute to the Donnan system. Variations of the Ringer's K+ concentrations, or the presence of 0.5 mM ouabain, demonstrated the permeability of the cell membrane to na+, K+, and Cl-. Cell volume changes: 0.5 mM ouabain produced a gradual swelling and ionic changes consistent with an inhibition of the sodium pump. In high-K+ media the cells swelled massively and the membrane depolarized. A linear relationship between cell volume changes and the Nernst potential for K+ was found. These properties are consistent with a pump-and-leak system for cell volume maintenance. The K+ -induced cell swelling was found to be reversible on transfer of the tissue to regular Ringer's. The extrusion of cell water was associated with an influx of Na+ into, and an efflux of K+ from, the cells (both fluxes down-hill), as well as extrusion of Cl- against its concentration gradient.2+

Amino Acids↗
PubMed1985

Postnatal growth and fatty acid synthesis in overgrown rat pups induced by fetal hyperinsulinemia.

Fetal hyperinsulinemia in the rat results in increased body weight, lipid content, and enhanced lipogenesis in liver and carcass. The purpose of our study was to determine whether the macrosomia and enhancement of fatty acid (FA) synthesis and/or content persisted postnatally in this animal model. Fetal hyperinsulinemia was produced in Sprague-Dawley rats by injecting fetuses with 2 units of insulin at 20.5 days of gestation. Alternate pups in the same litter were injected with saline. Pups were delivered surgically at 22.5 days of gestation, were weighed daily and sacrificed on day 15. FA content and synthesis rates of liver and skeletal muscle were measured. We found: (1) At birth, insulin-treated pups were 12% heavier than saline littermates, (5.88 +/- 0.14 g v 5.26 +/- 0.14 g, P less than .01); and (2) The enhanced growth associated with prenatal insulin treatment persisted during the suckling period, ie, compared with saline-treated controls, insulin pups were 15.7% heavier at 15 days of age (P less than .01); growth velocity of insulin pups, beginning on day 3, significantly exceeded that of control pups (P less than .05). FA contents of liver and muscle in insulin pups, (62.6 +/- 5.7 mumol/g and 62.7 +/- 13.2 mumol/g) were significantly greater (P less than .05) than in saline littermates (45.1 +/- 5.6 mumol/g and 30.2 +/- 4.7 mumol/g, respectively). We conclude that.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Muscle glutamine production in diabetic ketoacidotic rats.

The mechanism of activation of glutamine production by the hindlimb during diabetic ketoacidosis (DKA) was investigated in rats. Muscle glutamine production was estimated to account for over 90% of the total glutamine produced by the hindlimb. DKA produced significant increases in the concentrations of NH4+ and IMP in hindlimb muscles, suggesting that AMP deaminase is activated by DKA. NH4Cl- and HCl-induced acidosis did not produce these changes, indicating either that acidosis itself is not the stimulus for increased AMP deaminase activity or that the more severe degree of acidosis accompanying DKA is necessary for activation. Muscle glutamine concentrations were depressed in DKA. Experiments with isolated epitrochlearis muscle showed that the transport and permeability properties of the muscle cells (as judged by uptake and release of alpha-aminoisobutyrate and glutamine) were not altered by DKA. However, glutamine uptake by muscle cells was significantly inhibited by L-leucine, the concentration of which, along with other branched-chain amino acids, is markedly elevated in DKA.

Adipose Tissue↗
PubMed1983

Placental transfer of aromatic amino acids in non-human primates.

Macaca fascicularis (crab-eating monkeys) underwent an operative procedure at 120 to 130 days of pregnancy that allowed fetal blood sampling. During subsequent experiments L-phenylalanine and p-chlorophenylalanine were injected into the maternal circulation. Blood obtained from mother and fetus revealed that phenylalanine is actively transported across the placenta and hence is markedly increased in the fetus if the maternal blood phenylalanine concentration is below the "saturation" level of 1.82 mM to 2.12 mM. The results of these studies which provide a better understanding of placental transport mechanisms of aromatic amino acids will be of assistance in future management of pregnant phenylketonuric females.

Amino Acids↗
PubMed1982

Metabolism of L-lactate by LLC-PK1 renal epithelia.

LLC-PK1 renal epithelial cells do not appreciably synthesize D-glucose or glycogen from L-lactate under the conditions described. [U-14C]L-lactate is metabolized to [14C]L-alanine and [14C]L-glutamate. Synthesis of alanine but not glutamate is decreased by the transaminase inhibitor, aminooxyacetate. LLC-PK1 cells also produce unlabeled urea in the presence of [14C]L-lactate. Evidence for net gluconeogenesis has thus not been obtained for this cell line. This is interesting because the LLC-PK1 cells possess an active sugar transport system, and both active sugar transport and gluconeogenesis are localized together in vivo in the proximal tubule.

Animals↗
PubMed1981

Therapeutic attempts in infants with nonketotic hyperglycinaemia.

Identical male twins with non-ketotic hyperglycinaemia did not exhibit any development progress while on strychnine treatment. Since other therapeutic attempts with single agents previously had failed in most instances, we tried a combination of various treatment modalities. The results indicated that the administration of glycine receptor antagonist (strychnine) together with a low-protein diet (1.5 gm/kg/day), augmentation of 1-C units (N(5)-formlytetrahydrofolate), and removal of glycine from extracellular fluid (sodium salicylate and sodium benzoate) yielded some clinical improvement and positive biochemical changes in out patients.

Adrenocorticotropic Hormone↗
PubMed1980

Circulatory isolation of the liver for studying energy metabolism in trauma and sepsis.

An isolated level model was used in 25-30 kg pigs to study the uptake and/or release of various energy substrates across the liver and splanchnic bed during trauma and sepsis. This was accomplished by bypassing the hepatic portion of the inferior vena cava (IVC) using a polytetrafluoroethylene (PTFE) (IMPRA, Inc.) graphite-impregnated graft, from above the renal veins to the right atrial junction. The IVC was then ligated between the distal anastomosis and the liver. Sampling was done from inlying catheters placed in the main portal vein, hepatic vena cava, and an artery. Total hepatic blood flow was determined by the dye dilution technique. Our data showed the same pattern of metabolic derangements in both the traumatized and the septic-starved animals, but differed significantly from the normal fed controls. The correlation between glucogenesis and other energy functions of the liver and the proteolysis in skeletal muscle seen in trauma and sepsis is demonstrated. This model is functional and is applicable to the study of various kinds of shock and/or liver failure.

Amino Acids↗