scholarly journals Neurochemical Profile of Effects of 28 Neurotoxic Chemicals on the Central Nervous System in Rats. (1). Effects of Oral Administration on Brain Contents of Biogenic Amines and Metabolites.

1994 ◽  
Vol 32 (3) ◽  
pp. 145-164 ◽  
Author(s):  
Megumi KANADA ◽  
Muneyuki MIYAGAWA ◽  
Mitsuo SATO ◽  
Hiromichi HASEGAWA ◽  
Takeshi HONMA
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Oral Administration ◽  
Biogenic Amines ◽  
The Central Nervous System ◽  
Neurochemical Profile

Effect of amobarbital on the course of human dark adaptation

1961 ◽  
Vol 16 (2) ◽  
pp. 361-366 ◽  
Author(s):  
G. W. Granger
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Oral Administration ◽  
White Light ◽  
Dark Adaptation ◽  
Light Adaptation ◽  
Visual Adaptation ◽  
Test Field ◽  
The Central Nervous System ◽  
The Stability

Following light adaptation to a luminance of 120 mL for 5 minutes, absolute thresholds for a centrally fixated, 7-degree test field in 'white' light were measured during the course of 30 minutes' dark adaptation. Viewing was monocular and the measuring light was exposed in 0.018-second flashes. The resulting curves, defining the relation between log threshold luminance and time in the dark, displayed the typical features of 'rod' dark adaptation and were found to be highly reproducible in three experienced observers. Neither the shape of the curves nor their position along the log luminance axis was affected by the oral administration of a sedative dose (0.30 gm/70 kg) of amobarbital. It was concluded that the results supported the views of Hecht and other photochemical theorists concerning the stability of human dark adaptation and its resistance to fluctuations in the state of the central nervous system, but were not necessarily incompatible, as was sometimes supposed, with the hypothesis of a neural component in visual adaptation. Submitted on May 23, 1960

scholarly journals Brain Targeting of anti-HIV Nucleosides: in vitro and in vivo Evaluation of 6-chloro-2′,3′-dideoxypurine, a Lipophilic Prodrug of 2′,3′-dideoxyinosine

1994 ◽  
Vol 5 (5) ◽  
pp. 304-311 ◽  
Author(s):  
K. J. Doshi ◽  
F. D. Boudinot ◽  
J. M. Gallo ◽  
R. F. Schinazi ◽  
C. K. Chu
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Oral Administration ◽  
Intravenous Administration ◽  
Brain Targeting ◽  
The Central Nervous System ◽  
Intravenous And Oral Administration ◽  
The Brain

Lipophilic 6-halo-2′,3′-dideoxypurine nucleosides may be useful prodrugs for the targeting of 2′,3′-dideoxyinosine (ddl) to the central nervous system. The purpose of this study was to evaluate the potential effectiveness of 6-chloro-2′,3′-dideoxypurine (6-CI-ddP) for the targeting of ddl to the brain. In vitro studies indicated that the adenosine deaminase-mediated biotransformation of 6-CI-ddP to ddl was more rapid in mouse brain homogenate than in mouse serum. The brain distribution of 6-CI-ddP and ddl was assessed in vivo in mice following intravenous and oral administration of the prodrug or parent drug. Brain concentrations of ddl were similar after intravenous administration of 6-CI-ddP or ddl. However, after oral administration of the 6-CI-ddP prodrug, significantly greater concentrations of ddl were seen in the brain compared to those found after oral administration of ddl. The brain:serum AUG ratio (expressed as a percentage) of ddl after intravenous administration of 50 mg kg−1 of the active nucleoside was 3%. Following oral administration of 250 mg kg−1 ddl, low concentrations of ddl were detected in the brain. Brain:serum AUC ratios following intravenous and oral administration of the prodrug 6-CI-ddP were 19–25%. Thus, brain:serum AUC ratios were 6- to 8-fold higher after prodrug administration than those obtained after administration of the parent nucleoside. Oral administration of 6-CI-ddP yielded concentrations of ddl in the brain similar to those obtained following intravenous administration. The results of this study provide further evidence that 6-CI-ddP may be a useful prodrug for delivering ddl to the central nervous system, particularly after oral administration.

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