ABSTRACT
The development of biocompatible polymeric nanoparticles has become an important strategy for optimizing the therapeutic efficacy of many classical drugs, as it may expand their activities, reduce their toxicity, increase their bioactivity and improve biodistribution. In this study, nanoparticles of Amphotericin B entrapped within poly (lactic-co-glycolic) acid and incorporated with dimercaptosuccinic acid (NANO-D-AMB) as a target molecule were evaluated for their physic-chemical characteristics, pharmacokinetics, biocompatibility and antifungal activity. We found high plasma concentrations of Amphotericin B upon treatment with NANO-D-AMB and a high uptake of nanoparticles in the lungs, liver and spleen. NANO-D-AMB exhibited antifungal efficacy against Paracoccidioides brasiliensis and induced much lower cytotoxicity levels compared to D-AMB formulation in vivo and in vitro. Together, these results confirm that NANO-D-AMB improves Amphotericin B delivery and suggest this delivery system as a potential alternative to the use of Amphotericin B sodium deoxycholate.
Subject(s)
Amphotericin B/chemistry , Amphotericin B/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Deoxycholic Acid/chemistry , Deoxycholic Acid/pharmacology , Drug Carriers/chemistry , Lactic Acid/chemistry , Nanoparticles/chemistry , Polyglycolic Acid/chemistry , Amphotericin B/adverse effects , Amphotericin B/therapeutic use , Animals , Antifungal Agents/adverse effects , Antifungal Agents/therapeutic use , Deoxycholic Acid/adverse effects , Deoxycholic Acid/therapeutic use , Drug Carriers/pharmacokinetics , Drug Combinations , Drug Liberation , Lactic Acid/pharmacokinetics , Materials Testing , Mice , Paracoccidioides/drug effects , Paracoccidioides/physiology , Paracoccidioidomycosis/drug therapy , Polyglycolic Acid/pharmacokinetics , Polylactic Acid-Polyglycolic Acid Copolymer , Safety , Succimer/chemistry , Tissue DistributionABSTRACT
1. The effects of restraint stress on c-fos mRNA expression in the dentate gyrus were investigated by in situ hybridization. 2. Confirming previous findings, c-fos mRNA expression increased after 30 min of forced restraint. 3. This effect was attenuated by a previous i.c.v. injection of the anxiolytic benzodiazepine midazolam (20 nmol/2 microliters) or the N-methyl-D-aspartate (NMDA) receptor antagonist 2-amino-7-phosphonoheptanoic acid (AP-7; 5 nmol/2 microliters). 4. These results suggest that the dentate gyrus is activated during restraint stress and that this activation may be modulated by benzodiazepine gamma-aminobutyric acidA (GABAA) or NMDA receptors.
Subject(s)
2-Amino-5-phosphonovalerate/analogs & derivatives , Amino Acids/pharmacology , Gene Expression Regulation/drug effects , Genes, fos , Hippocampus/drug effects , Midazolam/pharmacology , RNA, Messenger/biosynthesis , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Stress, Physiological/genetics , Animals , Hippocampus/metabolism , Hippocampus/physiopathology , Immobilization , In Situ Hybridization , Male , RNA, Messenger/genetics , Rats , Rats, Wistar , Receptors, N-Methyl-D-Aspartate/physiology , Stress, Physiological/metabolism , Stress, Physiological/physiopathologyABSTRACT
To investigate the effects of stress on c-fos mRNA expression, rats were submitted to forced immobilization for 15, 30, 60 or 120 min before sacrifice. In situ hybridization was performed on sections containing the dorsal hippocampus with a 32P-labelled 50-base oligonucleotide probe (10(7)-10(9) cpm/micrograms) complementary to nucleotides 370-319 of rat c-fos. Forced restraint induced a time-dependent increase in c-fos mRNA expression which was most pronounced in the dentate gyrus and CA1-CA3 regions of the hippocampal formation, and which peaked after 30 min of immobilization (72.7 +/- 1.0 vs 24.1 +/- 0.8 cpm/mm2 in unrestrained animals). A positive but weaker signal was also detected in the amygdala, pyriform cortex and other parts of the cerebral cortex and habenulae. These results suggest that the hippocampal formation is activated during stress.
Subject(s)
Hippocampus/physiology , Proto-Oncogene Proteins c-fos/physiology , Stress, Physiological/physiopathology , Animals , Brain/physiology , In Situ Hybridization , Male , Proto-Oncogene Proteins c-fos/genetics , RNA, Messenger/physiology , Rats , Rats, Wistar , Restraint, Physical , Stress, Physiological/metabolism , Time FactorsABSTRACT
To investigate the effects of stress on c-fos mRNA expression, rats were submitted to forced immobilization for 15, 30, 60 or 120 min before sacrifice. In situ hybridization was performed on sections containing the dorsal hippocampus with a 32P-labelled 50-base oligonucleotide probe (10(7)-10(9) cpm/micrograms) complementary to nucleotides 370-319 of rat c-fos. Forced restraint induced a time-dependent increase in c-fos mRNA expression which was most pronounced in the dentate gyrus and CA1-CA3 regions of the hippocampal formation, and which peaked after 30 min of immobilization (72.7 +/- 1.0 vs 24.1 +/- 0.8 cpm/mm2 in unrestrained animals). A positive but weaker signal was also detected in the amygdala, pyriform cortex and other parts of the cerebral cortex and habenulae. These results suggest that the hippocampal formation is activated during stress.
Subject(s)
Animals , Male , Rats , Hippocampus , Proto-Oncogene Proteins c-fos/physiology , Stress, Physiological , Cerebrum , In Situ Hybridization , Proto-Oncogene Proteins c-fos/genetics , Rats, Wistar , Restraint, Physical , RNA, Messenger , Stress, Physiological , Time FactorsABSTRACT
To investigate the effects of stressful stimuli on pineal gland activity, male Wistar albino rats (200-250 g, 2-4 per group) were submitted to 30 min of forced immobilization or to unilateral vibrissotomy 30 min before sacrifice. In situ hybridization was performed with a 35S-labelled 50-base oligonucleotide probe complementary to nucleotides 270-319 of rat c-fos on sections containing the pineal gland. Autoradiograms were quantified using a JAVA microdensitometer. Stressful stimuli induced a significant increase in the expression of c-fos mRNA in the pineal gland (restraint = 144.3 +/- 14.4 cpm/mm2; hemivibrissotomy = 206.7 +/- 29.5 cpm/mm2) as compared to no restraint animals (30.6 +/- 5.1 cpm/mm2), animals displaying tonic-clonic seizures after an ip (64 mg/kg) injection of pentylenetetrazole (34.0 +/- 4.7 cpm/mm2), or competition (70.6 +/- 11.4 cpm/mm2) and RNAase-treated (52.7 +/- 9.1 cpm/mm2) controls. These results raise the possibility that stressful stimuli may interfere with pineal gland function.
