Cholecystokinin inhibits independent ingestion in neonatal rats

The ability of the octapeptide of cholecystokinin (CCK-8) to inhibit independent ingestion was examined in 8-h deprived 1- to 10-day-old rat pups consuming milk from the surface of a test chamber. CCK significantly reduced the volume of milk ingested in 1-day-old rat pups at a dose of 100 ng/kg. The threshold effective dosage for inhibition of intake increased with age up to 10 days of age. The specificity of this suppression was evaluated in three ways. First, behavioral observation indicated that ingestive but not noningestive behaviors were suppressed by CCK. Second, desulfated CCK-8 was ineffective in suppressing milk ingestion. Finally, CCK inhibited milk intake stimulated by deprivation but did not affect dehydration-induced milk ingestion in 3-day-old rat pups. In addition to inhibiting intake, CCK inhibited the rate of gastric emptying of saline test meals in 1- and 3-day-old rat pups, and the threshold dosages for this suppression were identical to the thresholds for the inhibition of ingestion. These results indicate that the gastrointestinal peptide CCK is both behaviorally and physiologically active in newborn rat pups and support a role for gastric inhibition in the satiety action of CCK.

Download Full-text

Effect of Breast Milk Ingestion Upon the Thyroxinemia of Suckling Rat Pups

Human Lactation 3 ◽

10.1007/978-1-4899-0837-7_51 ◽

1987 ◽

pp. 382-382

Author(s):

Linda V. Oberkotter

Keyword(s):

Breast Milk ◽

Rat Pups ◽

Milk Ingestion

Download Full-text

Behavioral evidence for cholecystokinin-opiate interactions in neonatal rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1988.255.6.r901 ◽

1988 ◽

Vol 255 (6) ◽

pp. R901-R907 ◽

Cited By ~ 2

Author(s):

A. Weller ◽

E. M. Blass

Keyword(s):

Dose Range ◽

Neonatal Rats ◽

Behavioral Measures ◽

Distress Vocalization ◽

Rat Pups ◽

Within Subjects ◽

Old Rats ◽

Behavioral Evidence ◽

Opioid Systems ◽

Mediated Reduction

In adult mammals, cholecystokinin (CCK)-opiate interactions are complex and task dependent. Specifically, CCK antagonizes opiate effects in some cases, yet acts similarly to opiate agonists in others. The present study used behavioral measures to determine how CCK interacts with opiates in neonatal rats. CCK, at doses of 1 microgram/kg and higher, markedly reduced isolation-induced distress vocalization in rat pups. Moreover, CCK selectively prevented naltrexone antagonism of opiate-mediated reduction in distress vocalization in 3- and 11-day-old rats. Yet CCK did not affect opiate-induced analgesia, as measured by the hot-plate paw-lift response. Thus CCK either did not interact with opiates or did so agonistically, with the same (low) dose range, and within subjects. These findings suggest independence of stress and pain systems in neonatal rats and demonstrate a functional interaction between CCK and opioid systems.

Download Full-text

Oxygen toxicity in newborn rats: the adverse effects of undernutrition

Journal of Applied Physiology ◽

10.1152/jappl.1982.53.5.1248 ◽

1982 ◽

Vol 53 (5) ◽

pp. 1248-1255 ◽

Cited By ~ 31

Author(s):

L. Frank ◽

E. Groseclose

Keyword(s):

Dna Content ◽

Oxygen Toxicity ◽

Lung Damage ◽

Newborn Rats ◽

Inhibitory Effects ◽

Similar Extent ◽

Newborn Rat ◽

Lung Maturation ◽

Rat Pups ◽

Growth Inhibitory

Undernutrition was found to compromise the tolerance of newborn rat pups to hyperoxia (greater than 95% O2 for 7 days). Survival rate for the normally nourished pups (11 pups/dam) was 56 of 77 (73%) but only 47 of 108 (44%) for the undernourished (18 pups/dam) group (P less than 0.005). Body growth, lung growth, and lung DNA content were significantly reduced by undernutrition. Hyperoxia inhibited these same parameters in both groups of pups. The growth inhibitory effects of O2 and undernutrition were additive, with an especially marked depression of lung DNA content (decreases 65%). Lung maturation was also markedly inhibited by O2 but to a similar extent in both nutrition groups. Despite the disparity in their O2 tolerance, 18/litter and 11/litter pups in O2 responded with equivalent increases in lung antioxidant enzymes. We suggest that the additive depressive effects of neonatal undernutrition and hyperoxia on lung DNA may compromise repair of ongoing O2-induced lung damage and help account for the compromised O2-tolerance we consistently observed even in the presence of significantly elevated antioxidant enzyme defenses.

Download Full-text

Human-derived probiotic Lactobacillus reuteri strains differentially reduce intestinal inflammation

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00124.2010 ◽

2010 ◽

Vol 299 (5) ◽

pp. G1087-G1096 ◽

Cited By ~ 107

Author(s):

Yuying Liu ◽

Nicole Y. Fatheree ◽

Nisha Mangalat ◽

Jon Marc Rhoads

Keyword(s):

Lactobacillus Reuteri ◽

Intestinal Inflammation ◽

Cow Milk ◽

Intestinal Cells ◽

Milk Formula ◽

Mrna Levels ◽

Newborn Rat ◽

Rat Pups ◽

Ifn Γ

Lactobacillus reuteri ( L. reuteri ) is a probiotic that inhibits the severity of enteric infections and modulates the immune system. Human-derived L. reuteri strains DSM17938, ATCC PTA4659, ATCC PTA 5289, and ATCC PTA 6475 have demonstrated strain-specific immunomodulation in cultured monocytoid cells, but information about how these strains affect inflammation in intestinal epithelium is limited. We determined the effects of the four different L. reuteri strains on lipopolysaccharide (LPS)-induced inflammation in small intestinal epithelial cells and in the ileum of newborn rats. IPEC-J2 cells (derived from the jejunal epithelium of a neonatal piglet) and IEC-6 cells (derived from the rat crypt) were treated with L. reuteri . Newborn rat pups were gavaged cow milk formula supplemented with L. reuteri strains in the presence or absence of LPS. Protein and mRNA levels of cytokines and histological changes were measured. We demonstrate that even though one L. reuteri strain (DSM 17938) did not inhibit LPS-induced IL-8 production in cultured intestinal cells, all strains significantly reduced intestinal mucosal levels of KC/GRO (∼IL-8) and IFN-γ when newborn rat pups were fed formula containing LPS ± L. reuteri . Intestinal histological damage produced by LPS plus cow milk formula was also significantly reduced by all four strains. Cow milk formula feeding (without LPS) produced mild gut inflammation, evidenced by elevated mucosal IFN-γ and IL-13 levels, a process that could be suppressed by strain 17938. Other cytokines and chemokines were variably affected by the different strains, and there was no toxic effect of L. reuteri on intestinal cells or mucosa. In conclusion, L. reuteri strains differentially modulate LPS-induced inflammation. Probiotic interactions with both epithelial and nonepithelial cells in vivo must be instrumental in modulating intrinsic anti-inflammatory effects in the intestine. We suggest that the terms anti- and proinflammatory be used only to describe the effects of a probiotic in the living host.

Download Full-text

Heterotransplantation of malignant human gliomas in neonatal rats

Journal of Neurosurgery ◽

10.3171/jns.1988.69.6.0928 ◽

1988 ◽

Vol 69 (6) ◽

pp. 928-933 ◽

Cited By ~ 2

Author(s):

Rafael J. Tamargo ◽

Jonathan I. Epstein ◽

Henry Brem

Keyword(s):

Human Glioma ◽

Neonatal Rats ◽

Sprague Dawley ◽

Human Gliomas ◽

Newborn Rat ◽

Content Type ◽

Sprague Dawley Rats ◽

Heterologous Transplantation ◽

Subcutaneous Space ◽

The Brain

✓ Three human glioma cell lines (TE-671 medulloblastoma, U-87 MG glioblastoma, and U-373 MG glioblastoma) were transplanted to the quadrigeminal cistern of the brain in 37 newborn Sprague-Dawley rats and to the subcutaneous space in 30 of their siblings. Two of the three gliomas (the TE-671 medulloblastoma and the U-87 MG glioblastoma) grew both intracranially and subcutaneously. The U-373 MG glioblastoma did not grow in either site. The resulting tumors expressed unique morphological features characteristic of their tissue of origin. The newborn rat represents a model for the heterologous transplantation of human gliomas, providing a biological window for the study of these lesions.

Download Full-text

TRANSFER OF MILK PROLACTIN TO THE PLASMA OF NEONATAL RATS BY INTESTINAL ABSORPTION

Journal of Endocrinology ◽

10.1677/joe.0.0790191 ◽

1978 ◽

Vol 79 (2) ◽

pp. 191-199 ◽

Cited By ~ 52

Author(s):

N. S. WHITWORTH ◽

C. E. GROSVENOR

Keyword(s):

Intestinal Absorption ◽

Mammary Glands ◽

Systemic Circulation ◽

Similar Increase ◽

Neonatal Rats ◽

Newborn Rat ◽

Young Rats ◽

Gastric Intubation ◽

Old Rats ◽

Exogenous Source

Prolactin passes from the systemic circulation of lactating rats into the milk where it can be consumed by the young rats during suckling. 131I-Labelled rat prolactin was detected in the plasma of 9- to 14-day-old rats after being nursed by mothers previously injected with 131I-labelled rat prolactin and after the pups had received 131I-labelled rat prolactin by gastric intubation. It was estimated that 16% of the 131I-labelled rat prolactin given by gastric intubation subsequently appeared in the plasma of the neonate. Gastric administration of 10·5 or 21·0 μg B-1 rat prolactin significantly raised the level of prolactin in the plasma of 13-day-old pups, but a similar increase was not observed when 27-day-old rats were given 46·2 μg B-1 prolactin by gastric intubation. The concentration of prolactin in the plasma of 13- to 14-day-old rats rose to 55 ng/ml 30 min after the onset of nursing by mothers whose mammary glands were full of milk, whereas the concentration in the plasma of offspring suckled by mothers with empty mammary glands remained at basal values. It is concluded that the intestine of the newborn rat is permeable to prolactin and that milk may constitute an exogenous source of prolactin for the suckled offspring.

Download Full-text

Behavioral displays to gustatory stimuli in newborn rat pups

Developmental Psychobiology ◽

10.1002/dev.420190303 ◽

1986 ◽

Vol 19 (3) ◽

pp. 163-174 ◽

Cited By ~ 51

Author(s):

Judith R. Ganchrow ◽

Jacob E. Steiner ◽

Silvia Canetto

Keyword(s):

Newborn Rat ◽

Rat Pups

Download Full-text

Inhaled nitric oxide decreases pulmonary endothelial nitric oxide synthase expression and activity in normal newborn rat lungs

ERJ Open Research ◽

10.1183/23120541.00060-2015 ◽

2016 ◽

Vol 2 (1) ◽

pp. 00060-2015 ◽

Cited By ~ 1

Author(s):

Thông Hua-Huy ◽

Sy Duong-Quy ◽

Hoa Pham ◽

Julien Pansiot ◽

Jean-Christophe Mercier ◽

...

Keyword(s):

Nitric Oxide ◽

Protein Expression ◽

Inhaled Nitric Oxide ◽

Control Group ◽

Enos Gene ◽

Newborn Rat ◽

Enos Expression ◽

Rat Pups ◽

Rat Lungs ◽

Expression And Activity

Inhaled nitric oxide (iNO) is commonly used in the treatment of very ill pre-term newborns. Previous studies showed that exogenous NO could affect endothelial NO synthase (eNOS) activity and expression in vascular endothelial cell cultures or adult rat models, but this has never been fully described in newborn rat lungs. We therefore aimed to assess the effects of iNO on eNOS expression and activity in newborn rats.Rat pups, post-natal day (P) 0 to P7, and their dams were placed in a chamber containing NO at 5 ppm (iNO-5 ppm group) or 20 ppm (iNO-20 ppm group), or in room air (control group). Rat pups were sacrificed at P7 and P14 for evaluation of lung eNOS expression and activity.At P7, eNOS protein expression in total lung lysates, in bronchial and arterial sections, was significantly decreased in the iNO-20 ppm versus control group. At P14, eNOS expression was comparable among all three groups. The amounts of eNOS mRNA significantly differed at P7 between the iNO-20 ppm and control groups. NOS activity decreased in the iNO-20 ppm group at P7 and returned to normal levels at P14. There was an imbalance between superoxide dismutase and NOS activities in the iNO-20 ppm group at P7.Inhalation of NO at 20 ppm early after birth decreases eNOS gene transcription, protein expression and enzyme activity. This decrease might account for the rebound phenomenon observed in patients treated with iNO.

Download Full-text