Biomedical subjects

O Peulen

Publications and source records attributed to O Peulen.

9 recordsLinked to original sources

PubMed2002

Spermine induces precocious development of the spleen in mice.

Spermine is a low molecular weight polyamine involved in the postnatal maturation of the gut. When it is administered orally to suckling rats, it induces maturation of the intestinal tract (liver, pancreas and small intestine). Here we show that this polyamine is able to induce precocious intestinal and splenic development in suckling mice. In fact, in 15-day-old mice which had received spermine orally twice daily for 3 days we observed an increase in the ratio of white pulp surface to total spleen surface in comparison with untreated mice. The two macrophage subsets of the marginal zone and the B-cell population were more developed and reached the development level of 5- or 10-week-old mice. The proliferation rate of B-cells was increased by spermine administration to pups. These observations suggest that spermine might play a role in immune system development; further investigation of its effects are intended, namely the evaluation of its capacity to enhance defence during the neonatal period.

Animals↗

PubMed2001

Spermine-Induced alteration of small intestine in suckling rat: involvement of apoptosis or Zn2+ enzymes?

Polyamines are of great importance in several physiological processes, such as cell proliferation and differentiation. The ingestion of spermine by suckling rats induces precocious maturation of their small intestine. Shortly after ingestion, spermine produces cell elimination at the villous top. The origin of this exfoliation was investigated to determine whether it was due to apoptosis. Wistar rats were orally treated with spermine. Apoptosis was analyzed in their small intestine by Tdt-mediated dUTP-fluorescein nick-end labeling reaction, caspase-3-like analysis, and DNA laddering. Polyamine content was measured by HPLC. The intestinal transitory alteration appeared as soon as 2 hr after spermine administration. Apoptosis events increased strongly at the same moment in the small intestine. They were evidenced by Tdt-mediated dUTP-fluorescein nick-end labeling analysis, DNA laddering, and caspase-3-like activity. Changes observed are consistent with apoptosis, but caspase inhibitor did not reduce intestinal alteration, as did Zn2+ chelator.

Animals↗

PubMed2001

Dietary polyamines and non-neoplastic growth and disease.

This review presents the data that are now available concerning the effects of dietary polyamines at either postnatal or adult stages in non-neoplastic growth and disease. Polyamines provided by food have a potential role in growth and development of the digestive system in neonatal mammals (and fishes). In humans, this property could be of importance in preventing the appearance of food allergies. Dietary polyamines also seem necessary for the maintenance of normal growth and general properties of adult digestive tract. Their possible therapeutic effects have been investigated in gastric, intestinal, and, more recently, whole-body healing.

Adult↗

PubMed2000

Are milk polyamines preventive agents against food allergy?

Insufficient polyamine intake could play a role in the induction of sensitization to dietary allergens. This proposal is based essentially on investigations made in sucking rats and in children. In sucking rats it has been established that oral administration of spermine can induce all the modifications occurring in the digestive tract at weaning. In the intestine events occur in two phases. The early event consists of desquamation of the epithelium resulting from an activation of apoptosis. The late event appears to involve an hormonal cascade in which adrenocorticotropic hormone, cytokines, bombesin and corticosterone are included. Observations in human subjects show that: (1) the spermine and spermidine concentrations are generally lower in infant formulas than in human breast milk. Mothers seem consistently to have relatively high or relatively low concentrations of spermine and spermidine in their milk. These individual variations may be due to diet, lifestyle or genetic background; (2) the probability of developing allergy can reach 80 % if the mean spermine concentration in the milk is lower than 2 nmol/ml milk. It is approximately 0 % if the mean spermine concentration is higher than 13 nmol/ml milk; (3) preliminary results show that the intestinal permeability to macromolecules differs in premature babies when they are fed on breast milk compared with infant formulas (J Senterre, J Rigo, G Forget, G Dandrifosse and N Romain, unpublished results). This difference does not seem to be present when powdered milk is supplemented with polyamines at the concentration found in breast milk; (4) spermine increases proliferation and differentiation of lymphocytes isolated from the tonsils of children.

Allergens↗

PubMed2000

Cyclosporine A inhibits partially spermine-induced differentiation but not cell loss of suckling rat small intestine.

The polyamines are of great importance in several biological processes, such as cell proliferation, and differentiation. The ingestion of spermine by suckling rats induces the precocious maturation of their small intestine. This phenomenon is preceded by a cell elimination at the villus tip. We hypothesize that these two phenomena could be mediated by the immune system and thus inhibited by an immunosuppressive agent such as cyclosporine A. Cyclosporine A inhibits, at least partially, the spermine-induced increase of the maltase- and sucrase-specific activities in the small intestine but failed to inhibit lactase-specific activity decrease and cell loss. Spermine does not act by the same mechanism in differentiation and in cell loss. Moreover, spermine acts in a different way on lactase-specific activity compared to maltase- or sucrase-specific activity. We hypothesize that spermine acts on differentiation by a T-cell/IL-2-dependent mechanism.

Animals↗

PubMed1999

[Statement on polyamines].

Polyamines are ubiquitous substances. Their intracellular concentration is controlled quickly and rigorously by extremely sophisticated systems. It depends on metabolism and cellular permeability. Polyamines act as structural and functional elements in the cell (nucleic acid conformation, cytoskeleton, radioprotection, apoptosis, proliferation and differentiation of cells...). They also play a role in various diseases (origin of food allergy, cancers...). They present a great therapeutic interest (oncology, molecular transfer to cell nucleus, transfer across the blood-brain barrier, parasitosis, effects on NMDA and GABA receptors in the central nervous system...).

Blood-Brain Barrier↗

PubMed1998

Comparison between the natural postnatal maturation and the spermine-induced maturation of the rat intestine.

In the suckling rats, orally provided spermine induced structural and biochemical changes in the intestine, which are characteristics of the postnatal maturation. This induced maturation was compared to that occurring spontaneously. Eight mumol spermine were administered orally once a day, for one or three days, to suckling rats which were 11 days old at the beginning of the experiment. The animals were killed 0, 2, 4, 6, 8, 10 hours or 3 days after the first treatment. Control rats from the same litter were treated in the same way but received only the vehicle. In order to complete the study of the naturally occurring maturation, another group of rats was killed when they were 12, 13, 15, 16, 17, 18, 19, 20, 21 or 30 days old. Animal and intestine weights were measured. Disaccharidase specific activity, and protein, DNA and RNA contents were estimated in the small intestine. Histological and ultrastructural aspects of the intestinal mucosa were examined. For all these parameters, the maturation induced by spermine ingestion appeared close to that occurring naturally at weaning. Consequently, dietary spermine induces all the morphological and biochemical modifications characterizing the intestinal postnatal maturation in the suckling rat suggesting a role of the polyamines in the naturally occurring processes.

Animals↗

PubMed1998

The relationship between spermine content of human milk during the first postnatal month and allergy in children.

DESIGN: Qualitative case study and mathematical model. SETTING: Belgium. OBJECTIVES: To evaluate the correlation between the polyamine mean concentration of the milk drunk during the first postnatal month and the appearance of allergy in children who drank this milk. RESULTS: A model that describes the dependence of the allergy appearance with the spermine mean concentration of milk drunk during the first postnatal month was established. CONCLUSIONS: This model shows that 5.02 nmol ml(-1) of spermine is a critical value to prevent the appearance of allergy.

Chromatography, High Pressure Liquid↗

PubMed1997

Role of interleukin-1 beta, interleukin-6, and TNF-alpha in intestinal maturation induced by dietary spermine in rats.

In the present investigation, the authors aimed to evaluate the role of cytokines in intestinal postnatal maturation induced by dietary polyamines. Neonatal rats were administered either saline (8 mumol) orally. Spermine increased interleukin-1 beta (IL-1 beta), IL-6, and TNF-alpha plasma concentration. The maximum concentrations of IL-1 beta, IL-6, and TNF-alpha were, respectively, observed at 4, 4, and 8 h posttreatment. Intraperitoneal (i.p.) injection of IL-1 beta increased the specific activity of sucrase in whole small intestine, whereas the specific activities of maltase and lactase were significantly enhanced only in the jejunum. IL-6 elicited sucrase and increased maltase specific activity in the whole small intestine, but lactase specific activity was not affected. TNF-alpha had no effect on sucrase and maltase specific activity, but a slight augmentation of lactase specific activity was detected in the jejunum. Spermine and spermidine content in the intestine was increased by i.p. injection of IL-1 beta and IL-6. Corticosterone secretion was elevated by single i.p. injection of IL-1 beta, IL-6, or TNF-alpha. These findings suggest that spermine could induce postnatal intestinal development and corticosterone secretion through a cytokine-dependent mechanism.

Animals↗