-transparent.png){kind=logo}
Previous studies have shown the existence of specific high affinity T3 binding sites in rat cerebrocortical synaptosomes. In this study, to define the localization of the binding sites, T3 binding to disrupted synaptic membrane fractions was compared with the binding to intact synaptosomes obtained from the rat cerebral cortex. Scatchard analysis revealed two orders of T3 binding sites with almost identical apparent dissociation constant (Kd) in synaptosomes and synaptic membrane fractions. However, the maximal binding capacity (MBC) of the higher affinity binding sites for synaptic membrane fractions was significantly greater than that for intact synaptosomes (4.2 +/- 0.2 vs 3.0 +/- 0.3 pg T3/mg protein). Regional distribution of the synaptosomal T3 binding sites in various areas of the rat brain was also studied. The Kd values were not significantly different in discrete brain regions. On the other hand, the MBCs of the higher affinity binding sites were greater in the cerebral cortex and hypothalamus (72.8 +/- 1.4 and 64.8 +/- 9.5 pg T3/g tissue) than in the cerebellum (22.1 +/- 1.6 pg T3/g tissue). Similar difference was also observed in the lower affinity sites. These results indicate that the specific T3 binding sites in brain synaptosomes are localized mainly on synaptic membranes and that the MBC is different in discrete brain regions.
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
January 1983,
Biochemical and biophysical research communications,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
July 1981,
Neuroscience letters,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
January 1991,
Neuroscience,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
January 1996,
Behavioural brain research,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
August 1981,
Life sciences,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
May 1992,
Brain research bulletin,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
August 1985,
Journal of endocrinological investigation,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
September 1977,
Neuropharmacology,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
June 1982,
Journal of neurochemistry,
Y Mashio, and
M Inada, and
K Tanaka, and
H Ishii, and
K Naito, and
M Nishikawa, and
K Takahashi, and
H Imura
March 1992,
Biochemical and biophysical research communications,
