Studies on the subsynaptosomal distribution of psychotropic drugs in rat cerebral cortex

After administration of H3-imipramine, H3-dimetacrine and S35-chlorpromazine by the direct lateral intraventricular injection, synaptosomes-rich fraction (F-B) was isolated from rat cerebral cortex by differential and 3-stepwise density gradient centrifugation. The isolated F-B fraction was treated by hyposmotic-lysis followed by freezing and thawing once or 15 times and, furthermore, fractionated into the subsynaptosomal distribution of these drugs showed the same distribution patterns, i.e., the larger portion of radioactivity was recovered in the synaptic ghost membranes-rich fractions. On the other hand, synaptic vesicles-rich fractions contained less radioactivity. On the disrupting process of F-B fraction, when the F-B fraction was treated by hyposmotic-lysis followed by freezing and thawing 15 times, only pellet (FD-6) fraction was obtained as compared with freezing and thawing once (4 interphase layers were obtained). Morphological examination revealed that the synaptic ghost membranes were located in the FD-6 fraction, but morphological damages were not observed. Under these conditions, H3-imipramine showed a 74.1% of release from the synaptosomes, while release with H3-dimetacrine and S35-chlorpromazine was 3.9 and 11.3%, respectively.

A moving spot high resolution scanning microspectrometer using focused laser illumination: illustrations with acriflavin stained sephadex beads and human fibroblast nuclei

We describe a high resolution moving spot scanning microspectrometer, capable of absorption or fluorescence detection, using focused laser illumination which is moved over the sample by rotating the laser beam direction prior to focusing. This rotation is achieved by reflecting the beam from mirrors mounted on bending mode piezoelectric transducers which, when bent by an applied voltage, cause the mirrors to rotate. The images of optically thin samples are analyzed by considering the convolution of the focused spot intensity distribution with the absorbance of a uniformly stained spherical particle. This analysis is verified experimentally with data from acriflavin stained Sephadex beads. Data from acriflavin-Feulgen stained human fibroblasts indicate that the efficiency of this type of nuclear staining is about 2 to 3 dye molecules incorporated per 100 nucleotide pairs. Quantitative data on fading of acriflavin fluorescence in stained fibroblasts indicate that fading is negligible in the time required to record the microscope images.

Beta-adrenergic receptors in rat myocardium: direct detection by a new fluorescent beta-blocker

A new fluorescent beta-blocker, 9-amino-acridin propranolol (9-AAP), was administered i.v. to rats. Multiple fluorescent 9-AAP binding sites were observed on cardiac muscle cells in frozen sections. Intensity and density of cardiac 9-AAP fluorescence were markedly reduced following pretreatment with (+/-)- and (-)-propranolol but not with (+)-propranolol. Our findings suggest that 9-AAP may label beta-adrenergic receptor sites in rat myocardium.

Colorimetric determination of isoniazid with 9-chloroacridine

A colorimetric method based on the interaction between isoniazid and 9-chloroacridine was developed. Analytical solutions are shaken for 30 min at 50 degrees, and the absorbance is measured at 500 nm. The procedure is sensitive for isoniazid in the 10(-5) M range. The method was applied to the analysis of isoniazid in pharmaceutical dosage forms and found to be comparable to the USP XVIII assay. Preliminary investigations suggested that the procedure is useful for the determination of free isoniazid in urine and plasma samples containing isoniazid metabolites.

Confirmation of iminoacridan structure of singly protonated 9-aminoacridine

The occurrence of the second absorption band of singly protonated 9-aminoacridine, which arises from an acridinium ring-localized transition, at anomalously short wavelength indicates the disruption of the aromaticity of the central ring of the singly charged cation. The shifting of the two longest wavelength absorption bands and the fluorescence band of 10-methyl-9-aminoacridine monocation, a model of singly protonated 9-aminoacridine which is constrained to dissociate from the exocyclic nitrogen atom, to shorter wavelengths, upon dissociation, indicates the imine-like nature of the 10-methyl derivative. Thes observations support the conclusion that the predominant site of positive charge in singly protonated 9-aminoacridine is the exocyclic nitrogen atom, even though the heterocyclic nitrogen atom is the site of protonation of the neutral molecule.

[Acridine-alkaloids from callus cultures of Ruta graveolens L]

Rutacridone, 1-hydroxy-N-methylacridone, and 1-hydroxy-3-methoxy-N-methylacridone have been isolated for the first time from callus cultures, which had been obtained from meristematic stem cells of Ruta graveolens L. The alkaloids were identified by co-chromatography with authentic compounds, by IR spectra, and by electronic spectra before and after addition of AlCl3. The use of the bathochromic shift by the AlCl3-complex in the analysis of acridine-alkaloids has been demonstrated for the first time.

Photoelectron microscopy: a new approach to mapping organic and biological surfaces

A general method of imaging organic and biological surfaces based on the photoelectric effect is reported. For the experiments, a photoelectron emission microscope was constructed. It is an ultrahigh vacuum instrument using electrostatic electron lenses, microchannel plate image intensifier, cold stage, hydrogen excitation source, and magnesium fluoride optics. The organic surfaces examined were grid patterns of acridine orange, fluorescein, and benzo(a)pyrene on a Butvar surface. A biological sample, sectioned rat epididymis, was also imaged by the new photoelectron microscope. Good contrast was obtained in these initial low magnification experiments. These data demonstrate the feasibility of mapping biological surfaces according to differences in ionization potentials of exposed molecules. A number of technical difficulties, such as the intensity of the excitation source, must be solved before high resolution experiments are practical. However, it is probable that this approach can be useful, even at low magnifications, in determination of the properties of organic and biological surfaces.

Chemical studies on an acriflavine-phosphotungstate complex; staining of phage deoxyribonucleic acid molecules for the electron microscope

Electrophoretic studies showed that the acriflavine-phosphotungstate (A-PTA) complex, which was formed by the reaction of acriflavine with phosphotungstic acid (PTA), contained a lower net positive charge than neutral acriflavine alone. Spectral studies from the titrations of specified aliquots of acriflavine with increasing volumes of PTA showed that the formation of A-PTA was characterized by a shift of the absorption peak of acriflavine from 452 mµ to a lower wavelength, at 446 mµ. The saturation of PTA binding sites on the acriflavine occurred when 3 molecules of dye reacted with 1 molecule of PTA. Binding curves of both neutral acriflavine and of A-PTA with "native" and with heat-denatured DNA showed shifts of λmax to longer wavelengths. A-PTA bound less native and less denatured DNA than the dye alone. The coupling of acriflavine with PTA caused a decrease in the net ability of the A-PTA complex to bind DNA. Double stranded DNA molecules from T3 bacteriophage were stained with the A-PTA complex for the electron microscope.