Short-term effects of spermine ingestion on the small intestine: a comparison of suckling and weaned rats

Effects of spermine supplementation on the morphology, digestive enzyme activities, and antioxidant capacity of intestine in weaning rats

The main objective of this study was to investigate the effects of different doses of spermine and its extended supplementation on the morphology, digestive enzyme activities, and intestinal antioxidant capacity in weaning rats. Nineteen-day-old male rats received intragastric spermine at doses of 0.2 and 0.4 μmol/g BW for 3 or 7 d, whereas control rats received similar doses of saline. The results are as follows: 1) In the jejunum, the seven-day supplementation with both doses of spermine significantly increased crypt depth (P < 0.05) compared with the control group; the supplementation extension of the high spermine dose increased villus height and crypt depth (P < 0.05); in the ileum, the low spermine dose significantly increased villus height and crypt depth compared with the control group for 7 days (P < 0.05). 2) The 3-day supplementation with high spermine dose increased alkaline phosphatase activity in the jejunum (P < 0.05). 3) In the jejunum, the anti-hydroxyl radical (AHR), total superoxide dismutase (T-SOD), catalase (CAT), and total antioxidant capacity (T-AOC) activities were increased (P < 0.05); however, the malondialdehyde (MDA) content was reduced (P < 0.05) in groups supplemented with the high spermine dose relative to those in the control groups after 3 and 7 d; moreover, the anti-superoxide anion (ASA) and glutathione (GSH) contents increased with the high spermine dose that lasted for 3 days (P < 0.05). Furthermore, the T-SOD and CAT activities (after 3 and 7 d), ASA (after 3 d), and AHR (after 7 d) increased with the high spermine dose compared with those of the low spermine dose (P < 0.05). Extending the supplementation duration (7 d) of the high spermine dose decreased the MDA content and ASA and T-AOC activities (P < 0.05). These results suggested that spermine supplementation can modulate gut development and enhance the antioxidant status of the jejunum in weaning rats, and a dosage of 0.4 μmol spermine/g BW had better effects than the dosage of 0.2 μmol spermine/g BW on accelerating gut development and increasing antioxidant capacity.

Spermine: new insights into the intestinal development and serum antioxidant status of suckling piglets

The present work aimed at investigating the effects of spermine supplementation and extended spermine administration on the intestinal morphology, enzyme activity, and serum antioxidant capacity of suckling piglets.

Effects of spermine on the morphology, digestive enzyme activities, and antioxidant status of jejunum in suckling rats

Spermine is a ubiquitous cellular component that plays vital roles in the maintenance of nucleic acids, regulation of kinase activities, protein synthesis, control of ion channel activities and renewal of the gut epithelium.

Polyamine levels in breast milk are associated with mothers' dietary intake and are higher in preterm than full-term human milk and formulas

BACKGROUND

Polyamine intake from milk is considered essential for post-natal maturation of the immune system and small intestine. The present study aimed to determine polyamine content in human milk after preterm delivery and the association with mothers' dietary intake. In comparison, the polyamine levels were compared with those in term breast milk and some corresponding formulas.

METHODS

Transitional breast milk was collected from 40 mothers delivering after 24-36 weeks of gestation, and from 12 mothers delivering after full term. Food intake was assessed in mothers delivering preterm babies using a 3-day diary. Polyamines were analysed by high-performance liquid chromatography.

RESULTS

The dietary intake of polyamines was significantly associated with breast milk content but weaker for spermine than for spermidine and putrescine. Total polyamine level was higher in preterm than term milk and lower in the corresponding formulas. Putrescine, spermidine and spermine contents [mean (SEM)] in preterm milk were 165.6 (25), 615.5 (80) and 167.7 (16) nmol dL⁻¹, respectively, with the levels of putrescine and spermidine being 50% and 25% higher than in term milk. The content of spermine did not differ.

CONCLUSIONS

Dietary intake of polyamines has an impact on the content in breast milk. The difference between human milk after preterm and term delivery might be considered when using donor human milk for preterm infants. The corresponding formulas had lower contents. Further studies are important for determining the relationship between tissue growth and maturation and optimal intake.

Excitatory regulation of angiotensin II on gastric motility and its mechanism in guinea pig

In the present study, we investigated the effect of Ang II on gastric smooth muscle motility and its mechanism using intracellular recording and whole-cell patch clamp techniques. Ang II dose-dependently increased the tonic contraction and the frequency of spontaneous contraction in the gastric antral circular smooth muscles of guinea pig. ZD7155, an Ang II type 1 receptor (AT(1)R) blocker, completely blocked the effect of Ang II on the spontaneous contraction of gastric smooth muscle. In contrast, TTX, a sodium channel blocker, failed to block the effect. Furthermore, nicardipine, a voltage-gated Ca(2+)-channel antagonist, did not block the effect of Ang II on the tonic contraction of gastric smooth muscle, but external free-calcium almost completely blocked this effect. Both ryanodine, an inhibitor of calcium-induced Ca(2+) release (CICR) from ryanodine-sensitive calcium stores, and thapsigargin, which depletes calcium in calcium stores, almost completely blocked the effect of Ang II on tonic contraction. However, 2-APB, an inositol trisphosphate (IP(3)) receptor blocker, significantly, but not completely, blocked the Ang II effect on tonic contraction. We also determined that Ang II depolarized membrane potential and increased slow wave frequency in a dose-dependent manner. It also inhibited delayed rectifying potassium currents in a dose-dependent manner, but did not affect L-type calcium currents or calcium-activated potassium currents. These results suggest that Ang II plays an excitatory regulation in gastric motility via AT(1)R-IP(3) and the CICR signaling pathway. The Ang II-induced inhibition of delayed rectifying potassium currents that depolarize membrane potential is also involved in the potentiation of tonic contraction and the frequency of spontaneous contraction in the gastric smooth muscle of guinea pig.

Effects of dietary polyamines at physiologic doses in early-weaned piglets

OBJECTIVE

Polyamines are essential for many cell functions, and they form part of the composition of maternal milk; despite this, their addition to infant formulas is currently under evaluation. The aim of the present study was to evaluate the effects of milk formulas designed to resemble sow milk supplemented with polyamines at maternal physiologic milk doses on the gut maturation of early-weaned piglets.

METHODS

We fed 30 newborn piglets with maternal milk (n=10), a control milk formula (n=10), or a milk formula supplemented with polyamines (5 nmol/mL of spermine and 20 nmol/mL of spermidine, n=10) for 13 d (day 2 after birth through day 15). Several growth and intestinal development parameters were measured.

RESULTS

The piglets fed the formula containing polyamine at physiologic doses showed significantly increased crypt depth in the small intestine compared with those fed with the control formula. Villus length was correlated to crypt depth. Although there were no differences in the disaccharidase activities between the animals fed the two formulas, alkaline phosphatase and gamma-glutamyl transferase activities tended to be higher in the jejunum of those fed the polyamine-supplemented diet. Dietary polyamines did not significantly modify the gut mucosal concentrations of putrescine, spermine, or spermidine.

CONCLUSION

Milk formulas supplemented with polyamines at maternal milk physiologic doses slightly enhanced gut growth and maturation in neonatal piglets.

Relaxant Effect of Spermidine on Acethylcholine and High K-induced Gastric Contractions of Guinea-Pig

In our previous study, we found that spermine and putrescine inhibited spontaneous and acetylcholine (ACh)-induced contractions of guinea-pig stomach via inhibition of L-type voltage-dependent calcium current (VDCC(L)). In this study, we also studied the effect of spermidine on mechanical contractions and calcium channel current (I(Ba)), and then compared its effects to those by spermine and putrescine. Spermidine inhibited spontaneous contraction of the gastric smooth muscle in a concentration-dependent manner (IC(50)=1.1+/-0.11 mM). Relationship between inhibition of contraction and calcium current by spermidine was studied using 50 mM high K(+)-induced contraction: Spermidine (5 mM) significantly reduced high K(+) (50 mM)-induced contraction to 37+/-4.7% of the control (p<0.05), and inhibitory effect of spermidine on I(Ba) was also observed at a wide range of test potential in current/voltage (I/V) relationship. Pre- and post-application of spermidine (5 mM) also significantly inhibited carbachol (CCh) and ACh-induced initial and phasic contractions. Finally, caffeine (10 mM)-induced contraction which is activated by Ca(2+)-induced Ca(2+) release (CICR),' was also inhibited by pretreatment of spermidine (5 mM). These findings suggest that spermidine inhibits spontaneous and CCh-induced contraction via inhibition of VDCC(L) and Ca(2+) releasing mechanism in guinea-pig stomach.

Polyamines and the intestinal tract

Owing to their high turnover, the intestinal mucosal cells have a particularly high requirement for polyamines. Therefore, they are an excellent charcol for the study of polyamine function in rapid physiological growth and differentiation. After a cursory introduction to the major aspects of polyamine metabolism, regulation, and mode of action, we discuss the contribution of the polyamines to the maintenance of normal gut function, the maturation of the intestinal mucosa, and its repair after injuries. Repletion of cellular polyamine pools with (D,L)-2-(difluoromethyl)ornithine has considerably improved our understanding of how the polyamines are involved in the regulation of normal and neoplastic growth. Unfortunately, the attempts to exploit polyamine metabolism as a cancer therapeutic target have not yet been successful. However, the selective inactivation of ornithine decarboxylase appears to be a promising chemopreventive method in familial adenomatous polyposis. Presumably, it relies on the fact that ornithine decarboxylase is a critical regulator of the proliferative response of the protooncogene c-myc, but not of its apoptotic response.

Oral administration of spermine advances intestinal maturation in sucking piglets

The objective of this study was to investigate the effect of orally administered spermine at various doses on intestinal maturation in sucking piglets. Thirty-six 11-day-old sucking piglets were assigned randomly to one of six treatments to receive via a stomach tube 0, 0·1, 0·2, 0·3, 0·4, or 0·5 mmol spermine per kg live weight (LW) per day for 3 days. At day 14 of age, duodenum, jejunum and ileum were obtained for biochemical and morphological analysis. Increasing the dose of orally administered spermine increased intestinal weight (linear effect, P<0·01), mucosal weight (linear effect, P<0·05), and mucosal protein, DNA and RNA contents of the duodenum (linear effect, P≤0·01) and jejunum (linear effect, P<0·01). Elevating spermine doses also enhanced (linear effect, P≤0·02) the specific activities of maltase and sucrase but decreased (linear effect, P<0·01) lactase specific activity in the jejunum and duodenum. Furthermore, augmenting oral doses of spermine increased crypt depth and villus width but reduced villus height in the jejunum (linear effect, P<0·05) and duodenum (linear effect, P<0·01). For most measurements, the effects were observed at the oral spermine doses of 0·3 to 0·5 mmol/kg LW per day. Collectively, the results show that oral administration of optimal doses of spermine to 11-day-old sucking piglets induces precocious intestinal maturation and promotes intestinal growth.

Effects of polyamines on contractility of guinea-pig gastric smooth muscle

This study was designed to investigate the effects of polyamines on mechanical contraction and voltage-dependent calcium current (VDCC) of guinea-pig gastric smooth muscle. Mechanical contraction and calcium channel current I(Ba) were recorded by isometric tension recording and whole-cell patch clamp technique. Spermine, spermidine and putrescine inhibited spontaneous contraction of the gastric smooth muscle in a concentration-dependent manner. Spermine (2 mM) reduced high K+ (50 mM)-induced contraction to 16+/-6.4% of the control (n=9), and significantly inhibited I(Ba) in a reversible manner (p<0.05; IC50=0.8 mM). Pre- and post-treatment of tissue with spermine (2-5 mM, n=10) also inhibited acetylcholine (10 microM)-induced phasic contraction to 5+/-6.4% of the control. Inhibitory effect of spermine on I(Ba) was observed at a wide range of test potentials of current/voltage (I/V) relationship (p<0.05), and steady-state activation of I(Ba) was shifted to the right by spermine (p<0.05). Spermidine and putrescine (1 mM each) also inhibited I(Ba) to 51+/-5.7% and 81+/-5.3% of the control, respectively. And putrescine (1 mM) inhibited I(Ba) at whole tested potentials (p<0.05) without significant change of kinetics (p<0.05). Finally, 5 mM putrescine also inhibited high K+-induced contraction to 53+/-7.1% of the control (n=4). These findings suggest that polyamines inhibit contractions of guinea-pig gastric smooth muscle via inhibition of VDCC.

Decrease in polyamines with aging and their ingestion from food and drink

Changes in polyamine levels during aging were measured in 3-, 10- and 26-week-old female mice. The level of polyamines in pancreas, brain, and uterus was maintained during these periods. The level of spermidine slightly decreased in intestine, and decreased significantly in thymus, spleen, ovary, liver, stomach, lung, kidney, heart and muscle during these periods. In skin, the level of spermidine was maximal in 10-week-old mice and markedly reduced in 26-week-old mice. The results suggest that maintenance of polyamine levels may play important roles in the function of the pancreas, brain and uterus in 3- to 26-week-old mice. We next looked for polyamine-rich food materials as a dietary source of polyamines. Foods found to be rich in polyamines included wheat germ, rice bran, black rice, Philippine mango, green pepper, Japanese pumpkin, nuts, fermented pickles, pond smelt, turban shell viscera, whelk viscera, salted salmon roe, salted cod roe, beef intestine (boiled) and liver of eel, beef, pork and chicken; and, as previously reported, soybean, fermented soybean (natto), mushrooms, orange and green tea leaf. These results offer useful information when it becomes necessary to ingest polyamines from food.

Biological significance of dietary polyamines

Polyamines are classically known by their names of putrescine, spermine, and spermidine. They are synthesized endogenously from ornithine and are interconvertible. In addition, an exogenous supply of polyamines is provided by dietary intake and by intestinal absorption from the products of bacterial metabolism. Polyamine uptake occurs almost entirely in the gut, and afterward the various forms are metabolized in different tissues under the strict regulation of ornithine decarboxylase, which is the first enzyme involved in their synthesis. Polyamines are eliminated from the organism by means of oxidation reactions, appearing in urine in all their metabolic forms. Polyamines play an important role in regulating cell growth and proliferation, the stabilization of negative charges of DNA, RNA transcription, protein synthesis, apoptosis, and the regulation of the immune response. They are components of breast milk and might be important in neonatal gut maturation, for which reason the possible supplementation of infant formulas with these compounds is under study.

Intestinal effects of long-lasting spermine ingestion by suckling rats

Spermine ingestion induces the precocious maturation of the small intestine in suckling rats. Previous observations suggest that spermine-induced intestinal maturation is a two-step phenomenon. The first step is the elimination of immature enterocytes (4-10 h post spermine ingestion) and the second step is the replacement of previous immature cells by adult-type enterocytes (2-3 days post initial spermine administration). The spermine-induced maturation is reversible when spermine administration is stopped. This work was undertaken in order to check whether the extension of polyamine administration (for 3-7 days) after the appearance of spermine-induced maturation can retain the mature state of the small intestine. Our results indicate that extension of spermine administration does not prevent some parameters (sucrase and maltase specific activities) reverting to a typical 'immature' value while others remain at a typical 'mature' level (mucosal weight and lactase specific activity). Our results show that there are at least two different mechanisms in required for the control of spermine-induced maturation of the small intestine.