No abstract available.
Humans ; Polyamines*

No abstract available.
Breast Neoplasms* ; Breast* ; Cell Proliferation* ; MCF-7 Cells ; Polyamines

Dendrimers are hyperbranched, monodisperse and three dimensional macromolecules, which consist of an apolar core and polar shell have been referred to as "unimolecular micelles". This paper briefly describes the development and structural characteristics of dendrimers and also explains the feature of dendrimers as drug carrier and the dendrimer-drug interactions in details. Recently, dendrimers, which have attracted increasing attention for their applications in many fields such as drug targeted delivery systems and gene transfection, are becoming potential novel carriers.
Dendrimers ; chemistry ; Drug Delivery Systems ; Drug Design ; Polyamines ; chemistry

Air ; analysis ; Chromatography, High Pressure Liquid ; methods ; Polyamines ; analysis ; Workplace

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

No abstract available.
Breast Neoplasms* ; Breast* ; Eflornithine* ; Estrogens ; Humans* ; MCF-7 Cells ; Phosphorylation* ; Polyamines

PURPOSE: Although androgens are the main steroids controlling the growth of prostate glands, estrogens are also important in the regulation of its growth. Prostate cancer cells, like other cancer cells, maintain high levels of polyamines. In LNCaP cells, apoptosis is induced by mifepristone. During the process of cell death, the regulation of ROS production, caspase-3 activation and poly (ADP-ribose) polymerase cleavage were investigated in the presence of estrogen and polyamines to identify their possible roles. MATERIALS AND METHODS: The cell growth was assessed using the MTT assay, and the intracellular ROS production by the DCFH-DA assay. The p53 protein expression, activation of caspase-3 and PARP cleavage were checked by Western blotting, with specific antibodies to each. RESULTS: The growth and viability of the cells were significantly inhibited, in a dose- and time-dependent manners, by mifepristone (MIF) treatment. The production of ROS were dependent on the MIF dosage. The activation of caspase-3 and cleavage of PARP also increased with the duration of MIF treatment. The expression of p53 protein also increased with increases in the MIF incubation time. E2 severely inhibited the ROS production, caspase-3 activation and PARP cleavage. However, polyamines only inhibited the ROS production, without influencing the caspase-3 activation or PARP cleavage. CONCLUSION: In LNCaP cells, MIF induces apoptosis through ROS production. The expression of p53 protein, caspase-3 activation and PARP cleavage accompanied the process of apoptosis. The apoptotic processes were inhibited by E2, but polyamines only inhibited the ROS production, implying the multifunctional role of E2, in addition to its role as a free radical scavenger.
Androgens ; Antibodies ; Apoptosis* ; Blotting, Western ; Caspase 3 ; Cell Death ; Estrogens* ; Mifepristone ; Polyamines* ; Prostate* ; Prostatic Neoplasms* ; Steroids

Animals ; Biogenic Polyamines ; metabolism ; Biological Transport ; Humans ; Paraquat ; poisoning ; Pulmonary Edema ; metabolism

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