Effect Of Spermine Research Articles

Стрес-протекторний вплив путресцину і сперміну на рослини пшениці за ґрунтової посухи

Polyamines are considered multifunctional stress metabolites in plants. The ability of exogenous polyamines to increase plant resistance to adverse factors of various nature is well-known. At the same time, the stress-protective effects of polyamines at the level of whole plants under conditions of dehydration close to natural have not been sufficiently studied. The aim of this work was to study the effect of foliar treatment of wheat plants with solutions of putrescine and spermine on the functioning of their protective systems during drought under laboratory soil culture conditions. In the experiments, we used young wheat plants (Triticum aestivum L.), which were subjected to a 4-day drought with a gradual decrease in the water content in the soil to 25% of the total moisture capacity. Spraying plants with putrescine in a concentration range of 0,25-5 mM significantly reduced the growth-inhibiting effect of drought; the effect of spermine was less effective, but also significant at P ≤ 0,05. Putrescine significantly reduced the manifestation of water deficit caused by drought. Under the action of spermine, only a tendency towards a decrease in the water deficit of the leaves was noted. Drought caused the effect of oxidative stress, which was manifested in an increase in the content of malondialdehyde (MDA) in leaves. During the pretreatment of plants with spermine, the increase in the MDA content was partially leveled, and under the action of putrescine it was leveled almost completely. Treatment of plants with both polyamines at concentrations of 1 and 5 mM promoted preservation of the pool of chlorophylls and carotenoids in leaves under stress conditions. Moreover, when plants were treated with putrescine and spermine under drought conditions, a close to usual ratio of chlorophylls a/b was maintained. The proline content in leaves increased significantly under the influence of drought. Pretreatment with 1 and 5 mM putrescine, and 5 mM spermine reduced effect of proline content growth in leaves, caused by drought. At the same time, the treatment of plants with both polyamines caused the accumulation of sugars in the leaves. Under the influence of drought, the content of anthocyanins and flavonoids absorbing in the UV-B region significantly decreased in the leaves. Pretreatment with spermine somewhat mitigated the negative effect of drought on the anthocyanin content. Under the action of both putrescine and spermine, the content of flavonoids absorbing in UV-B stabilized in leaves. It was concluded that the protective effect of polyamines on wheat plants under drought conditions is primarily due to the regulation of water metabolism and the prevention of oxidative damage.

Molecular-scale drug delivery systems loaded with oxaliplatin for supramolecular chemotherapy

Smart strategies that can decrease the side effect and enhance the therapeutic efficacy of chemotherapy are in urgent need to meet the special demands of cancer therapy. Herein, two water-soluble macrocyclic hosts, i.e., a carboxylated leaning tower[6]arene (CLT6) and a carboxylated [2]biphenyl-extended pillar[6]arene (CBpP6), are used to load chemotherapy drug oxaliplatin (OxPt) by forming inclusion complexes (OxPt⊂CLT6 and OxPt⊂CBpP6) through host-guest interactions. Interestingly, OxPt can be released from the macrocyclic cavities of these drug delivery systems (DDSs) via the competitive binding effect of spermine (SPM) because of the stronger binding abilities of CLT6/CBpP6 toward SPM as compared with OxPt, leading to enhanced cytotoxicity on SPM-overexpressed cancer cells, such as breast cancer MCF-7 cells. Moreover, compared to free OxPt, due to the low concentration of SPM in normal cells, OxPt⊂CLT6 and OxPt⊂CBpP6 demonstrated a decreased cytotoxicity on liver L02 cells, which is beneficial for reducing the side effect of anticancer drug during chemotherapy. Such a strategy might be extended to other antitumor drugs and water-soluble macrocycles with suitable cavity sizes to achieve controllable drug delivery and enhanced anticancer ability in supramolecular chemotherapy

The Effect of Spermidine and Spermine on Chitosan-Mediated Gene Delivery

Chitosan (CS) is a biodegradable and highly positive charged polymer that can be utilized as a non-viral vector for gene delivery. However, its transfection efficiency is low. Spermidine (SPD) and spermine (SPM) are ordinary polyamines found in almost all living organisms. Their structures contain tri- and tetra-amine, respectively. The present study aims to elucidate the effect of SPD or SPM on transfection efficiency and cytotoxicity of CS/DNA complexes in human cervical carcinoma (HeLa) cells. The ternary complexes (CS, DNA and SPD or SPM) at different weight ratios and mixing orders were formulated and tested on transfection efficiency. Their particle sizes and charges were also estimated. CS that has a molecular weight of 45,000 Daltons and degree of deacetylation of 85 was able to form complete complex with plasmid DNA expressing enhanced green fluorescence protein (pEGFP-C2) at weight ratio of 4. The SPM/CS/DNA (1:4:1) and SPD/ CS/DNA (512:4:1) complexes illustrated the greatest transfection efficiency. Moreover, the transfection efficiency was affected by the mixing order between CS, DNA and SPD or SPM. For cell toxicity experiments, more than 85% the average cell survival of the complexes were detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) cell growth assay. These findings suggest that addition of either SPD or SPM to CS before forming ternary complexes with DNA may significantly improve gene delivery potential in vitro.

Effects of TiO2 nanoparticles and spermine on antioxidant responses of Glycyrrhiza glabra L. to cold stress

Licorice (Glycyrrhiza glabra L.) is known as an important medicinal plant throughout the world. Glycyrrhizin is one of the most important specialized metabolites produced by licorice. In order to study the effect of TiO2 nanoparticles (TiO2 NPs) and spermine on physiological and biochemical traits of licorice under cold stress conditions, a factorial experiment was conducted in a completely randomized design with three replications. Plants were exposed to optimum temperature (26 ºC) as control and low temperature (4 ºC) as cold stress conditions and also treated with TiO2 NPs (2 and 5 ppm) and spermine (1 mM), separately. Results from physiological and biochemical analyses of the aerial parts of licorice seedlings showed that the growth parameters and the content of photosynthetic pigments decreased in response to low temperature. TiO2 NPs and spermine treatments increased plant resistance to cold stress and decreased the level of oxidative damage by reduction of malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents. In other hand, TiO2 NPs and spermine caused increase of phenolics, total protein and osmolytes contents under cold stress conditions. An increase in glycyrrhizin content was significantly induced by low temperature, TiO2 NPs and spermine.

Effects of spermine and putrescine polyamines on capsaicin accumulation in Capsicum annuum L. cell suspension cultures

This study examined the effects of different concentrations of spermine (Spm) and putrescine (Put) elicitors on capsaicin production at different times in cell suspension culture of peper (Capsicum annuum L‘Kahramanmaraş Hat-187’.), raised from pepper seeds. Callus was obtained from hypocotyl explants of pepper seedlings germinated in vitro conditions, and cell suspensions were prepared from calluses. Spm (0.1, 0.2 and 0.4 mg l-1) and Put (0.1, 0.2 and 0.4 mg l-1) elicitors were applied on cell suspensions, and control groups free from elicitor treatment were created. The amount of capsaicin in cells was found to be higher in the control groups and samples treated with Spm elicitors when compared to filtrates. The highest increase in the capsaicin amount in cells was determined on day 12 of elicitation with 0.2 mg l-1 Spm application. The highest capsaicin amount passing into the filtrate was determined as 0.1 mg l-1 Spm on day 8. The most effective Put concentration and time on capsaicin amount were found as 0.2 mg l-1 Put on day 12 in both cells and filtrates. The highest total capsaicin was also determined in the 0.2 mg l-1 Spm application on day 12with 312.747 ± 8.70 µg g-1 of culture. Exogenous treatment of Spm and Put elicitors affected capsaicin accumulation.

Effect of exogenous spermine pretreatment on alleviating renal fibrosis in diabetic nephropathy mice and its related mechanism

Objective: To observe the protective effects of exogenous spermine on renal fibrosis induced by diabetic nephropathy (DN) and to explore its mechanism.Methods: Twenty-four male C57 mice were randomly divided into control group, type 1 diabetes group (TID) and spermine pretreatment group (TID+Sp, n=8 in each group). TID mice were induced by STZ (60 mg/kg), and TID+Sp mice were pretreated with spermine (5 mg/(kg·d)) for 2 weeks before STZ injection. The mice were killed at the 12th week. The renal function was determined by serum creatinine and urea nitrogen. HE, PAS and Masson staining were used to evaluate renal tissue injury and fibrosis. The expressions of matrix metalloproteinase (MMP-2, MMP-9) and collagen IV (Coll-IV) in the kidney of mice were detected by Western blot. Results: Compared with the control group, the blood glucose (5.67±0.22 vs 28.40±0.57 mmol/L), creatinine (14.33±1.22 vs 30.67±4.73 μmol/L) and urea nitrogen (6.93±4.94 vs 22.00±1.04 mmol/L) in the T1D group were increased significantly (P＜0.05), the glomerular basement membrane was thickened, the collagen was significantly increased, the expressions of MMP-2, MMP-9 and Coll-IV protein were increased (0.57±0.07 vs 1.06±0.20, 47.00±0.04 vs 1.29±0.09 and 0.42±0.16 vs 0.95±0.18,P＜0.05). Exogenous spermine significantly alleviates the above-mentioned changes. Conclusion: Exogenous spermine pretreatment could significantly alleviate renal fibrosis in diabetic mice by regulating the balance between MMPs and collagen.

Spermine attenuates high glucose-induced myocardial fibrosis by regulating the cell cycle

Objective: To investigate the protective effect of spermine (Sp) on diabetic cardiomyopathy (DCM) and high glucose-induced cardiac fibroblasts (CFs), and to explore its mechanism.Methods: ①Animal experiments: 24 male Wistar rats were randomly divided into control group, type 1 diabetes group (TID) and spermine group (TID+Sp, each group n=8). TID rats were induced by streptozocin (STZ, 60 mg/kg), and TID+Sp rat were pretreated with spermine (Sp, 5 mg/(kg·d)) for 2 weeks before STZ injection. After 12 weeks of modeling, blood glucose, insulin levels, ejection fraction (EF) and shortening fraction (FS) were measured, and Masson staining and Sirius red staining were performed in the rat cardiac tissues. ②Cell experiments: primary CFs were extracted from newborn (1-3 d) Wistar rat hearts, and were randomly divided into control group, high-glucose group (HG) and HG+Sp group (n=6 per group). HG group was treated with 40 mmol/L glucose, and the HG+Sp group was pretreated with 5 μmol/L Sp for 30 min before HG treatment. The cell viability of CFs was detected by CCK8, the content of collagen in culture medium was analyzed by ELISA, and protein expressions of cell cycle related proteins (PCNA, CyclinD1 and P27) were detected by Western blot. Results: Compared with control group, the blood glucose and collagen content were increased, and the insulin level and heart function were decreased in the T1D group. Meanwhile, HG induced an increasing of the cell viability, the collagen content in the medium and the expressions of PCNA and CyclinD1, while the expression of P27 was down-regulated. Spermine could reduce the above changes, manifested as improving the cardiac function, regulating the expression of cyclin and reducing the level of myocardial fibrosis. Conclusion: Spermine can alleviate myocardial fibrosis in diabetic cardiomyopathy, which mechanism is related to the regulation of cell cycle.

Effect of Germination Temperature, Spermine and Putrescine on Pollen Viability of Strawberry

Effect of Germination Temperature, Spermine and Putrescine on Pollen Viability of Strawberry

Spermidine and spermine delay brain aging by inducing autophagy in SAMP8 mice.

The natural polyamine spermidine and spermine have been reported to ameliorate aging and aging-induced dementia. However, the mechanism is still confused. An aging model, the senescence accelerated mouse-8 (SAMP8), was used in this study. Novel object recognition and the open field test results showed that oral administration of spermidine, spermine and rapamycin increased discrimination index, modified number, inner squares distance and times. Spermidine and spermine increased the activity of SOD, and decreased the level of MDA in the aging brain. Spermidine and spermine phosphorylate AMPK and regulate autophagy proteins (LC3, Beclin 1 and p62). Spermidine and spermine balanced mitochondrial and maintain energy for neuron, with the regulation of MFN1, MFN2, DRP1, COX IV and ATP. In addition, western blot results (Bcl-2, Bax and Caspase-3, NLRP3, IL-18, IL-1β) showed that spermidine and spermine prevented apoptosis and inflammation, and elevate the expression of neurotrophic factors, including NGF, PSD95and PSD93 and BDNF in neurons of SAMP8 mice. These results indicated that the effect of spermidine and spermine on anti-aging is related with improving autophagy and mitochondrial function.

Exogenous spermine attenuates rat diabetic cardiomyopathy via suppressing ROS-p53 mediated downregulation of calcium-sensitive receptor

Diabetic cardiomyopathy (DCM) is a severe complication of type 1 diabetic (T1D) patients, manifested as combined diastolic and systolic dysfunction. DCM is associated with impaired calcium homeostasis secondary to decreased calcium-sensitive receptor (CaSR) expression. Spermine, a direct agonist of CaSR, was found deficient in cardiomyocytes of T1D rats. However, the role of spermine in DCM was unclear. Here, we examined the cardioprotective effect of exogenous spermine on DCM in streptozotocin (STZ) induced-T1D rats and high-glucose (HG)-incubated neonatal rat cardiomyocytes. Exogenous spermine significantly attenuated cardiac dysfunction in T1D rats, characterized by improved echocardiography, less fibrosis, reduced myocardial endoplasmic reticulum (ER) stress and oxidative stress, and increased expression of myocardial membrane CaSR. In cultured neonatal rat cardiomyocytes, exogenous spermine attenuated myocardial injury induced by HG treatment, demonstrated by restored cellular glucose uptake capacity, reduced expression of apoptotic markers, lowered level of oxidative stress, ER stress and unfolded protein response, and upregulated cell membrane CaSR. Mechanistically, the cardioprotective effect of spermine appeared dependent upon effective elimination of reactive oxygen species (ROS) and up-regulation of CaSR expression by suppressing the Nrf2-ROS-p53-MuRF1 axis. Taken together, these results suggest that exogenous spermine protects against DCM in vivo and in vitro, partially via suppressing ROS and p53-mediated downregulation of cell membrane CaSR.

The effect of activated κ-opioid receptor (κ-OR) on the role of calcium sensing receptor (CaSR) in preventing hypoxic pulmonary hypertension development

κ-opioid receptor (κ-OR) plays a key role in preventing hypoxic pulmonary hypertension (HPH) development after activated by exogenous agonist U50,488H. Calcium sensing receptor (CaSR) activation induces HPH by promoting vasoconstriction and vascular remodeling. The activated κ-OR is reported to inhibit the expression of CaSR in pulmonary artery smooth muscle cells (PASMCs). Thus, in this study, we aimed to explore the effect of activated κ-OR on the role of CaSR in preventing HPH development. An HPH rat model was constructed using Sprague-Dawley rats. Changes in mean pulmonary arterial pressure (mPAP) and right ventricular pressure (RVP) mediated by κ-OR agonist U50,488H and CaSR inhibitor NPS2143 were observed. The effects of CaSR agonist spermine and inhibitor NPS2143 on pulmonary artery tension were tested. The expression and localization of κ-OR and CaSR were measured in isolated PASMCs. A cell-counting kit-8 assay was performed to evaluate the effect of spermine in PASMC proliferation. Expression of proliferating cell nuclear antigen (PCNA), Erk, and p-Erk was evaluated by western blot analysis. Results showed that κ-OR and CaSR were co-expressed and colocalized in PASMCs under normoxic and hypoxic conditions. Interactions between κ-OR and CaSR were also observed. Spermine improved vasoconstriction in the pulmonary artery in HPH rats, which was abolished by U50,488H. RVP and mPAP were significantly increased in HPH rats under CaSR stimulation, but were significantly reduced when the rats were pretreated with U50,488H and NPS2143 (P < 0.01). Spermine treatment significantly promoted PASMC proliferation, which was significantly inhibited by U50,488H, p38 inhibitor SB203580, JNK inhibitor SP600125, Erk inhibitor SCH772984, and MEK inhibitor U0126, especially Erk inhibitor (P < 0.01). Spermine significantly increased PCNA and P-Erk expression in hypoxic conditions, which was inhibited by U50,488H and NPS2143. κ-OR stimulation prevented HPH development via the CaSR/MAPK signaling pathway.

Effect of Spermine and Putrescine on Germination and Growth of Vigna Radiate (L.) R. Wilczek Seeds

Polyamines are polycationic hydrocarbons that is found in all plant parts that regulates growth and development. In current study, seeds treated with polyamines,Spermine and Putrescine were studied to evaluate the growth and development in terms of various physiological and biochemical parameters. For this study, seeds were soaked in different strengths of Spermine and Putrescine (0.01mM, 0.1mM and 1mM) for 48 hours and distilled water was used as control. After sprouting, seeds were transferred into half strength M.S. medium and evaluated at every 48 hours for 10 days. Highest seed germination (95%) was obtained in control after 24 hours and it was observed that germination was less in higher concentrations of polyamines. Out of all treatments, 0.01mM concentration showed maximum concentration compared to 0.1mM and 1mM polyamine concentration. First leaves were observed in Putrescine and Spermine treated seeds after 24 hours whereas, first leaves in distilled water treated seeds were observed after 30 hours. Statistical analysis using One Way ANOVA and Dunn’s Post hoc analysis were performed to check the relationship between protein concentration, shoot length, chlorophyll a and b content. It was observed that there is a significant relationship between total protein content and chlorophyll a and b content and also between shoot length and chlorophyll a and b content.However, no significant relationship was observed between shoot length and protein concentration. An attempt has been made to characterize protein profile using SDS-PAGE, however no distinct band was found in treated seeds compared to control.

Effects of spermine on ileal physical barrier, antioxidant capacity, metabolic profile and large intestinal bacteria in piglets.

Spermine, a polyamine, exerts important roles in alleviating oxidative damage, improving immunity, increasing antioxidant status and digestive enzyme activities, and promoting the development of small intestine. However, information is not available regarding the effects of spermine supplementation on gut barrier function, intestinal microbiota and metabolic profile in piglets. Therefore, this study was designed to explore the effect of spermine administration on these parameters. The experiment was conducted on twenty 12 day-old suckling piglets, which were allocated either to the group fed basal formula milk (control group) or to that fed a basal formula milk that contained spermine (0.4 mmol kg−1 BW per day) for 3 days. Caecal and colonic digesta and ileal tissues were collected at the end of the three-day feeding experiment. The results were as follows: (1) supplementation with spermine increased glutathione S-transferase (GST) capacity by 27.84% and glutathione content by 18.68% in the ileum (P < 0.05). (2) Glutathione peroxidase 1 (GPx1), catalase (CAT), GST, nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein1 (Keap1) mRNA levels in ileum were increased in the spermine-supplemented group in contrast to those in the control group (P < 0.05). (3) The spermine-supplemented group increased zonula occludens-1 (ZO-1) (by 42.0%), ZO-2 (by 101.0%), occludin (by 84.0%), claudin 2 (by 98.0%), claudin 3 (by 121.0%), claudin 12 (by 47.0%), claudin 14 (by 68.0%) and claudin 16 (by 73.0%) mRNA levels in ileum relative to the control group (P < 0.05). (4) Supplementation with spermine increased ZO-2 and occludin mRNA levels in ileum by reducing myosin light chain kinase (MLCK) (by 23.0%) mRNA level. (5) Spermine supplementation increased choline, glycerolphosphocholine, creatine and serine levels, and decrease alanine, glutamate, lysine, phenylalanine, threonine, lactate, tyrosine levels in ileum (P < 0.05). (6) The population of Lactobacilli, Bifidobacteria and total bacteria increased, but the number of Escherichia coli decreased in the caecal and colonic digesta after spermine supplementation (P < 0.05). In summary, dietary spermine supplementation promotes ileal health by enhancing antioxidant properties, improving ileal barrier function, modulating metabolic profiles, and maintaining large intestinal microbial homeostasis.

Rac1/PLC-γ1 Signalling Pathway to Mediate the Protective Effects of Spermine on Intestinal Barrier Integrity of Piglets

Rac1/PLC-γ1 Signalling Pathway to Mediate the Protective Effects of Spermine on Intestinal Barrier Integrity of Piglets

PSVII-36 Examining the effect of a physiological dose of the polyamine; spermine, on myogenic regulatory transcription factor expression

Abstract Examining the effect of a physiological dose of the polyamine; spermine, on myogenic regulatory transcription factor expression. Spermine is a micronutrient derived from amino acids. It affects cell growth, proliferation, differentiation and gene regulation in many cell types. Polyamines have long been overlooked with respect to their biological effects on muscle growth. Myogenic regulatory factors (myoD, myf5) initiate, promote and regulate myogenesis. Supporting myogenic transcription factors transcription and by such enhancing muscle production in livestock, through nutrition may be possible with dietary spermine supplementation. We examined the effect of spermine (0.5mM) in undifferentiated c2c12 muscle cells at two time points (8hr and 16hr). Using TaqMan-MGB qRT-PCR we quantified mRNA for key myogenic regulatory factors in a minimum of three experiments each containing 3 technical replicates. We report a significant increase in myoD (P = 0.02) and myf5 (P = 0.05) mRNA at 8hr following spermine treatment as compared to controls (no spermine). After 16 hr exposure to spermine (0.5mM) treatment myoD (P = 0.01) remained significantly different from controls. Our results indicate that spermine supports myogenesis through expression of increased myogenic regulatory factors at early stages of myogenesis. These findings support the need to further test the hypothesis that spermine promotes increased muscle growth and ultimately may represent a dietary means to maximize muscle growth in livestock species.

Effects of polyamines on agronomic traits and photosynthetic physiology of wheat under high temperature stress

Two spring wheat varieties were used to study alleviating effects of exogenous spermine (Spm) and spermidine (Spd) on agronomic traits and photosynthesis under high temperature treatment (HT). Our results showed that HT significantly decreased grain mass per panicle of heat-resistant variety (XC 6) by 25% and heat-sensitive variety (XC 31) by 32%. After HT, i.e., at 13 d after flowering, the decrease in net photosynthetic rate of XC 6 (38%) was lower than that of XC 31 (53%); the reason for this was related to XC 6, which could maintain correspondingly normal chlorophyll content (Chl), stomatal conductance (gs), transpiration rate (E), and intercellular CO2 concentration. Exogenous Spm and Spd could increase relative water content, Chl, gs, E, the maximal quantum yield of PSII photochemistry, effective quantum yield of PSII photochemistry, antenna conversion efficiency, and photochemical quenching coefficient of flag leaves under HT. Our results indicated that the heat resistance of XC 6 is better than that of XC 31 and exogenous Spm and Spd could alleviate the heat injury of photosynthesis of wheat flag leaves.

Influence of spermine and nitrogen deficiency on growth and secondary metabolites accumulation in Castilleja tenuiflora Benth. cultured in a RITA® temporary immersion system.

The effect of exogenous spermine (SPM) on Castilleja tenuiflora shoots developing under nitrogen deficiency (ND) stress was evaluated. Shoots cultivated in a temporary immersion system were subjected to four experimental treatments: (1) control; (2) exogenous SPM; (3) ND; and (4) ND+SPM. Shoots were longer in the ND+SPM treatment (6.3 ± 0.5 cm) than in the ND treatment (4.2 ± 0.5 cm). The total chlorophyll content was similar in the control and SPM treatments (0.41 µg mg−1 FM) and the highest values of total phenolic content were detected at 21 days in the ND+SPM treatment (84.1 ± 0.05 GAE g−1 DM). In the ND+SPM treatment, the phenylalanine ammonia lyase activity increased earlier than in ND treatment, and reached its maximum at day 21 (3.9 ± 0.2 µmol E‐CIN h−1 mg−1 protein). Compared with the control, the ND and ND+SPM treatments resulted in increased secondary metabolites contents in both root and aerial parts. The strongest effect was in the roots, where the SPM and ND+SPM treatments both resulted in increased quercetin content (4.3‐fold that in the control). Our results showed that SPM partially counteract the damage caused by ND and results in increased contents of valuable bioactive compounds.

Electrophysiological evaluation of extracellular spermine and alkaline pH on synaptic human GABAA receptors

Polyamines have fundamental roles in brain homeostasis as key modulators of cellular excitability. Several studies have suggested alterations in polyamine metabolism in stress related disorders, suicide, depression, and neurodegeneration, making the pharmacological modulation of polyamines a highly appealing therapeutic strategy. Polyamines are small aliphatic molecules that can modulate cationic channels involved in neuronal excitability. Previous indirect evidence has suggested that polyamines can modulate anionic GABAA receptors (GABAARs), which mediate inhibitory signaling and provide a direct route to reduce hyperexcitability. Here, we attempted to characterize the effect that spermine, the polyamine with the strongest reported effect on GABAARs, has on human postmortem native GABAARs. We microtransplanted human synaptic membranes from the dorsolateral prefrontal cortex of four cases with no history of mental or neurological disorders, and directly recorded spermine effects on ionic GABAARs responses on microtransplanted oocytes. We show that in human synapses, inhibition of GABAARs by spermine was better explained by alkalization of the extracellular solution. Additionally, spermine had no effect on the potentiation of GABA-currents by diazepam, indicating that even if diazepam binding is enhanced by spermine, it does not translate to changes in functional activity. Our results clearly demonstrate that while extracellular spermine does not have direct effects on human native synaptic GABAARs, spermine-mediated shifts of pH inhibit GABAARs. Potential spermine-mediated increase of pH in synapses in vivo may therefore participate in increased neuronal activity observed during physiological and pathological states, and during metabolic alterations that increase the release of spermine to the extracellular milieu.

Effect of different polyamines on some physiological traits, growth, and development of basil (Ocimum basilicum L.) in salt stress under hydroponic culture conditions

Effect of polyamines on parental and hybrid strains of Bombyx mori Aparna Yerra, Anitha Mamillapalli

Effect of multi-micronutrient and spermine Foliar Application on Yield and Fruit Quality of alphonse mango

Effect of multi-micronutrient and spermine Foliar Application on Yield and Fruit Quality of alphonse mango