No abstract available.
Animals ; Medulla Oblongata* ; Putrescine* ; Rats*

OBJECTIVETo investigate the effects of putrescine on the growth and differentiation of human bone marrow mesenchymal stem cells (MSC) to develop a new inductive medium mixture for their osteogenic differentiation.

METHODSHuman bone marrow MSC were collected from three healthy donors and were used to observe the growth-promoting activity of putrescine with MTT test. Experiments were divided into 3 groups: (1) putrescine group, (2) positive control group (presence of dexamethasone, ascorbate, and glycerol phosphate) and negative group (d-alpha with 5% FCS). The cellular expression level of Runx-2 was detected by PCR assay after the culture was maintained for 1 week. After 2 weeks, the intracellular activity of alkaline phosphatase was revealed by histochemistry staining, the phosphatase activity, and the protein concentration in the cell lysates were also detected. Furthermore, MSC were cultured in the presence of putrescine for 2 weeks and Oil-red O staining was performed to reveal the differentiated adipocytes; the cells induced by the standard agent cocktail were used as the positive control.

RESULTSPutrescine promoted the proliferation of human marrow MSC in a dose-dependent manner. MSC exposed to putrescine at a concentration of 100 µmol/L for 1 week expressed greatly higher level of Runx-2, compared with the negative control. Alkaline phosphatase activity was evidently observed after MSC were maintained in the presence of putrescine for 2 weeks. The phosphatase activity contrasted to the protein content in putrescine-treated MSC was significantly higher than that of the control cells (0.87±0.012 vs 0.52±0.010) (P<0.01), and also greatly higher than that of the positive control (0.83±0.029) (P=0.02). Oil red O staining showed that MSC treated by putrescine did not differentiate into adipoblasts.

CONCLUSIONPutrescine can promote the proliferation and osteogenic differentiation of MSC, suggesting the potential application of putrescine as a novel inductive agent for in vitro osteogenesis of MSC.

Bone Marrow ; Cell Differentiation ; Humans ; Mesenchymal Stromal Cells ; Osteogenesis ; Putrescine

OBJECTIVETo explore the effect of exogenous putrescine on renal function and cell apoptosis in rats.

METHODSNinety SD rats were randomized into control group (n=10), high-dose putrescine group (P1 group, n=40), and low-dose putrescine group (P2 group, n=40) with intraperitoneal injections of 2 ml of normal saline, 50 µg/g putrescine, and 25 µg/g putrescine, respectively. At 24, 48, 72 and 96 h after the injections, 10 rats from each group were sacrificed to examine serum Cr and BUN levels, histological changes in the kidneys, and renal cell apoptosis (TUNEL assay).

RESULTSThe rats in the two putrescine- treated groups showed mild edema in some renal tissues without obvious necrosis. In P1 and P2 groups, serum Cr and BUN levels differed significantly at each time point of measurement (P<0.01 and P<0.05, respectively), and were significantly higher than the levels in the control group (P<0.01 and P<0.05, respectively). The two putrescine-treated groups showed gradually increased renal cell apoptosis with time, reaching the peak levels at 96 h and 48 h, respectively. The peak renal cell apoptosis rates in P1 [(24.78∓2.19)%] and P2 [(26.27∓2.13)%] group were significantly higher than the rate in the control group [(4.47∓0.33)%, P<0.01].

CONCLUSIONExogenous putrescine can lead to renal function impairment and induce renal cell apoptosis in rats, and the severity of these changes appeared to be associated with the blood concentration of exogenous putrescine.

Animals ; Apoptosis ; drug effects ; Kidney ; drug effects ; physiopathology ; Putrescine ; adverse effects ; blood ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: The present study was designed to identify the stress-induced polyamine (PA) response and its modulation by chronic treatment of lithium in brain (hippocampus) and periphery (liver). METHOD: For immobilization stress, rats (230-250 g, male) were placed in restrainer once daily, for 3h. All biochemical measurements were done 5h after the beginning of immobilization stress application. Stress application was done for 5 days and, after a resting interval of 7 days, rats were subjected to an additional stress. Additional groups were subjected to same stress schedule, but during the 7 day interval, one group received once daily injections of 2.5 mmol/kg lithium chloride subcutaneously, and other received saline. RESULTS: The putrescine (PU) level was increased after each stress episode. After cessation of the intermittent stress period, an additional stress 7 days later led again to an increase in PU level in brain but not in liver. The later increase in PU level was blocked by lithium treatment during the intervening 7 day interval between stressors. CONCLUSION: The results suggest that long-term lithium treatment can inhibit an overreactive PA response in brain. So, maladjustment of a stress induced PA response may be a factor to the affective illness and can be target of lithium.
Animals ; Appointments and Schedules ; Brain* ; Immobilization ; Lithium Chloride ; Lithium* ; Liver ; Putrescine ; Rats

PURPOSE: This study was designed to investigate the effects of polyamines on rabbit seminal vesicular contractility. MATERIALS AND METHODS: The polyamines; putrescine, spermidine and spermine, were added to deepithelized and precontracted seminal vesicle strips, with either 10 4M norepinephrine (NE), 10 4M acetylcholine (ACh) or 70mM KCl, in organ chambers to obtain cumulative concentration response curves. A whole cell mode patch clamp study was also performed to observe the effects of the polyamines on the L-type calcium channel activities. RESULTS: The polyamines elicited concentration-dependent relaxations of the precontracted strips with the NE, ACh and KCl. The spermine showed the most potent relaxation response. Both extracellular and intracellular application of the spermine decreased the L-type calcium channel currents. CONCLUSIONS: Spermine more potently inhibited the seminal vesicle contraction than putrescine or spermidine, which suggests the polyamines may play a role in maintaining the basal tonicity of seminal vesicle in a flaccid state. The spermine-induced relaxation response seems to be related with an inhibition of the L-type calcium channel activities.
Acetylcholine ; Calcium Channels, L-Type ; Norepinephrine ; Polyamines* ; Putrescine ; Relaxation* ; Seminal Vesicles* ; Spermidine ; Spermine

The effects of DFMO or/and putrescine on the dexamethasone-induced apoptosis of CEM cells were studied to investigate the role of polyamines in anti-leukemic glucocorticoid action. Dexamethasone-induced apoptosis was preceded by significant decreases of cellular polyamine contents and putrescine uptake activity. But DFMO produced decreases of putrescine and spermidine contents and marked increase of putrescine uptake activity, but did not induce apoptosis. However, dexamethasone and DFMO, respectively, induced G|1-arrest in cell cycle and hypophosphorylation of pRb, resulting in the increase of G|1 to S ratio and decrease of CEM cell count. DFMO enhanced the dexamethasone-induced apoptosis and G|1-arrest. On the other hand, putrescine little affected the apoptotic and G|1-arresting activities of dexamethasone, but almost suppress the effects of DFMO and also the DFMO-dependent enhancement of dexamethasone effects. These results suggested that the dexamethasone-induced apoptosis to be associated with pRb hypophosphorylation and G|1-arrest in CEM cells might be ascribed to the concomitant decreases of cellular polyamine contents and putrescine uptake activity.
Apoptosis* ; Cell Count ; Cell Cycle ; Dexamethasone ; Hand ; Humans* ; Polyamines ; Putrescine ; Spermidine

Interactions among dexamethasone, dehydroepiandrosterone (DHEA), lipopolysaccharide (LPS), and antimycin A on the glutamate uptake and the polyamine uptake were investigated in primary cultures of rat cerebral cortical astrocytes to examine the effects of dexamethasone and DHEA on the regulatory role of astrocytes in conditions of increased extracellular concentrations of glutamate or polyamines. 1. (3H)Glutamate uptake: LPS and antimycin A decreased Vmax, but both drugs had little effect on Km. Dexamethasone also decreased basal Vmax without any significant effect on Km. And dexamethasone further decreased the antimycin A-induced decrease of Vmax. DHEA did not affect the kinetics of basal glutamate uptake and the change by LPS or antimycin A. 2. (14C)Putrescine uptake: LPS increased Vmax, and antimycin A decreased Vmax. They showed little effect on Km. Dexamethasone decreased Vmax of basal uptake and further decreased the antimycin A-induced decrease of Vmax, and also decreased Vmax to less than control in LPS-treated astrocytes. DHEA did not affect Km and the change of Vmax by LPS or antimycin A. 3. (14C)Spermine uptake: Antimycin A decreased Vmax, and LPS might increase Vmax. Km was little affected by the drugs. Dexamethasone decreased basal Vmax and might further decrease the antimycin A-induced decrease of Vmax. And dexamethasone also decreased Vmax to less than control in LPS-treated astrocytes. DHEA might increase basal Vmax and Vmax of LPS-treated astrocytes. 4. Vmax of glutamate uptake by astrocytes was increased by putrescine (1000 muM & 2000 muM) and spermidine (200 muM, 500 muM & 2000 muM). Spermine, 200 muM (and 100 muM), also increased Vmax, but a higher dose of 2000 muM decreased Vmax. Km of glutamate uptake was not significantly changed by these polyamines, except that higher doses of spermine showed tendency to decrease Km of glutamate uptake. In astrocytes, dexamethasone inhibited the glutamate uptake and the polyamine uptake in normal or hypoxic conditions, and the polyamine uptake might be stimulated by LPS and DHEA. Polyamines could aid astrocytes to uptake glutamate.
Animals ; Antimycin A* ; Astrocytes* ; Dehydroepiandrosterone* ; Dexamethasone* ; Glutamic Acid* ; Kinetics ; Polyamines ; Putrescine ; Rats* ; Spermidine ; Spermine

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 (VDCCL). In this study, we also studied the effect of spermidine on mechanical contractions and calcium channel current (IBa), 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 (IC50=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 IBa 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 Ca2+-induced Ca2+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 VDCCL and Ca2+releasing mechanism in guinea-pig stomach.
Acetylcholine ; Caffeine ; Calcium ; Calcium Channels ; Carbachol ; Contracts ; Muscle, Smooth ; Putrescine ; Relaxation ; Spermidine ; Spermine ; Stomach

Ornithine decarboxylase (ODC) is a key enzyme in the biosynthetic pathway of polyamines and catalyzes the decarboxylation of ornithine to produce putrescine. Inhibition of ODC activity is a potential approach for the prevention and treatment of many diseases including cancer, as the expression levels and the activities of ODC in many abnormal cells and tumor cells are generally higher than those of normal cells. The discovery and evaluation of ODC inhibitors rely on the monitoring of the reaction processes catalyzed by ODC. There are several commonly used methods for analyzing the activity of ODC, such as measuring the yield of putrescine by high performance liquid chromatography, or quantifying the yield of isotope labelled carbon dioxide. However, the cumbersome operation and cost of these assays, as well as the difficulty to achieve high-throughput and real-time detection, hampered their applications. In this work, we optimized a real-time label-free method for analyzing the activity of ODC based on the macromolecule cucurbit[6]uril (CB6) and a fluorescent dye, DSMI (trans-4-[4-(dimethylamino) styryl]-1-methylpyridinium iodide). Finally, the optimized method was used to determine the activities of different ODC inhibitors with different inhibition mechanisms.
Bridged-Ring Compounds ; Imidazoles ; Ornithine ; Ornithine Decarboxylase ; Ornithine Decarboxylase Inhibitors ; Putrescine

OBJECTIVE: The present study was designed to identify the acute and chronic immobilization stress-induced polyamine (putrescine) responses and their modulation by administration of melatonin in brain regions (frontal cortex and hippocampus) and gastrointestinal tract regions (GIT, gastric mucosa and duodenal mucosa). METHOD: For immobilization stress (3 or 14 days), rats (250-300 g, male Sprague-Dawley rats) were placed in restrainers once daily, for 3 h. Melatonin (10 mg/kg, i.p.) was administered once daily immediately after stress. Rats were sacrificed 2 h after the final application of stress for the measurement of putrescine levels. RESULTS: The putrescine levels of frontal cortex, hippocampus, gastric mucosa and duodenal mucosa were significantly increased by acute stress (p<0.05, p<0.05, p<0.0005 and p<0.01, respectively). The putrescine levels of frontal cortex and duodenal mucosa were significantly increased by chronic stress (p<0.05, respectively). In chronic stress group, animals showed adaptation tendency. The changes of putrescine level in gastric and duodenal mucosa induced by chronic stress were significantly lower than those by acute stress (p<0.05, respectively). The putrescine responses to acute stress in frontal cortex, hippocampus, gastric mucosa and duodenal mucosa were attenuated by administration of melatonin (p<0.01, p<0.05, p<0.05 and p<0.05, respectively). The putrescine response to chronic stress in frontal cortex was attenuated by melatonin administration (p<0.05, respectively). CONCLUSION: The results suggested that putrescine may play a role in stress response of brain regions (frontal cortex and hippocampus) and GIT regions (gastric and duodenal mucosa). Melatonin can inhibit the stress-induced putrescine responses in the brain and GIT.
Animals ; Brain* ; Gastric Mucosa ; Gastrointestinal Tract* ; Hippocampus ; Humans ; Immobilization* ; Male ; Melatonin* ; Mucous Membrane ; Putrescine ; Rats ; Rats, Sprague-Dawley