Premium
Brain Transfer Coefficients for 67 Ga: Comparison to 55 Fe and Effect of Calcium Deficiency
Author(s) -
Murphy Vincent A.,
Rapoport Stanley I.
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb09341.x
Subject(s) - albumin , chemistry , calcium , metal , medicine , serum albumin , endocrinology , analytical chemistry (journal) , biochemistry , chromatography , biology , organic chemistry
The transfer coefficients (Kia) for the uptake of gal‐lium‐67 ( 67 Ga) into brain and CSF were determined in un‐anesthetized male Fischer‐344 rats fed either a normal or a low‐Ca diet. K in for 67 Ga was also compared with transfer coefficients for the uptake of iron‐55 ( 55 Fe) and 125 I‐albumin in control animals. The value of CSF 67 Ga K in was 3 × 10 −7 ml·g −1 ·s −1 and was 50% larger in low‐Ca animals. Brain regional K in values for 67 Ga were 3‐9 × 10 −7 ml·g −1 ·s −1 with no differences in Kia between normal and low‐Ca rats. CSF Km values for 55 Fe were 40% and those for albumin were 15% of Kia for 67 Ga. For brain, K in values for 55 Fe were 15‐40% smaller than for 67 Ga, but for albumin the K in values were 85% less than for 67 Ga. 67 Ga was found to be 99% bound to plasma proteins, whereas 55 Fe was 99.9% bound. The results indicate that metals that are primarily bound to trans‐ferrin enter the CSF and brain very slowly. Uptake of both metals was faster than albumin, which may indicate that metal bound to small chelates contributes significantly to brain uptake. In addition, Ca deficiency does not enhance entry of Ga into the brain.