geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Stereospecific transport of triiodothyronine from plasma to cytosol and from cytosol to nucleus in rat liver, kidney, brain, and heart


, : Stereospecific transport of triiodothyronine from plasma to cytosol and from cytosol to nucleus in rat liver, kidney, brain, and heart. Journal of Clinical Investigation 75(1): 147-154

We have investigated the transport of L- and D-triiodothyronine (T3) from plasma to cellular cytoplasm and from cytoplasm to nucleus by estimating the concentration of free hormone in these compartments in rat liver, kidney, brain, and heart. We assessed the distribution of T3 in various tissues and its metabolism by standard isotopic techniques and measured plasma and cytosolic tissue T3 by radioimmunoassay. In addition, we determined the fraction of radiosensitive T3 associated with the cytosol in individual tissues and estimated the cytosolic volume per gram of tissue. Equilibrium dialysis allowed us to determine the binding power of cytosols and plasma, and in vitro saturation techniques provided values for the affinity (ka) for L- and D-T3 of isolated nuclei in aqueous solution at 37 degrees C. We calculated the free cytosolic hormone from the product of cytosolic T3 and the binding power of cytosol for T3, and the free intranuclear T3 from the ka and previously determined ratio of occupied-to-unoccupied binding sites under steady state conditions in euthyroid animals. Our results showed that the free cytosolic/free plasma concentrations for L-T3 and D-T3, respectively, were: liver 2.8, 21.6; kidney 1.17, 63.3; heart 1.31, 1.58; brain 0.86, 0.24. The free nuclear/free cytosolic ratios for L-T3 and D-T3, respectively, were: liver 58.2, 3.70; kidney 55.9, 1.54; heart 80.6, 24.9; and brain 251, 108.6. Our findings suggest that stereospecific transport occurs both from plasma to cytosol and from cytosol to nucleus. The high gradients from cytosol to nucleus imply that there is an energy-dependent process and appear to account for the differences in the nuclear association constant determined in vivo and in vitro.

US$19.90

PMID: 3965501

DOI: 10.1172/JCI111667


Other references

Copeland S.; Milligan J.G.L.; Harron D.W.G.; Riddell J.G., 1988: The effects of diltiazem on the affinity density and function of human lymphocyte beta adrenoceptors. British Journal of Clinical Pharmacology 25(5): 660P-661P

Bajnóczky, K.; Meggyessy, V., 1985: Coincidence of paternal 13pYq translocation and maternal increased 13p NOR activity in a child with arthrogryposis and other malformations. Cytogenetic examination of a boy with congenital multiple arthrogryposis, VSD and dysmorphic facies revealed a probable t(Y; 13)(q?; p1) translocation and three NOR-positive dots on one of the chromosomes 13. The latter variant could be followed i...

Fort, J.; Crema, E.R.; Madella, M., 2016: Modeling Demic and Cultural Diffusion: An Introduction. Identifying the processes by which human cultures spread across different populations is one of the most topical objectives shared among different fields of study. Seminal works have analyzed a variety of data and attempted to determine whether em...

Mozolevskaya, E.G., 1979: Features of the utilization of food resources by xylophagous insects. An account of a theoretical and experimental investigation based on the population of Blastophagus [Tomicus] piniperda. It is shown that the dependence of pest population on the amount of food, the number of trees suitable for colonization, or the...

Joshi, V.S.; Reinhardt, J.M.; Garvin, M.K.; Abramoff, M.D., 2015: Automated method for identification and artery-venous classification of vessel trees in retinal vessel networks. The separation of the retinal vessel network into distinct arterial and venous vessel trees is of high interest. We propose an automated method for identification and separation of retinal vessel trees in a retinal color image by converting a vess...

Sunquist, Fiona., 1993: In your face. How animals from cats to walruses see with their whiskers. International Wildlife. November-December; 236: 4-11

Morell, Virginia, 1996: Computer culture deflects women and minorities. Part of a special section on women and minorities in science. The numbers of women working in computer science have fallen since 1988, a striking statistic for a field with a reputation for openness. Even in 1988, only two African-Americans of eit...

Okagami, N.; Esashi, Y.; Nagao, M., 1977: Gibberellin-induced inhibition and promotion of sprouting in aerial tubers of Begonia evansiana Andr. in relation to photoperiodic treatment and tuber stage. GA3 treatment of B. evansiana buds on stem cuttings inhibited the formation of aerial tubers and increased sprouting of developing tubers when applied from the beginning to the 10th day of short day treatment; however, when applied after the 10th...

Dugas, J.R.; Barrett, A.M.; Beason, D.P.; Plymale, M.F.; Fleisig, G.S., 2016: Tibiofemoral contact biomechanics following meniscocapsular separation and repair. Meniscocapsular separations are often seen in knees with other intra-articular pathology. The consequences of these tears with regard to knee contact mechanics are currently unknown, and the biomechanical advantages of repair have not been measure...

Schleef, M.; Blaesen, M.; Schmeer, M.; Baier, R.; Marie, C.; Dickson, G.; Scherman, D., 2011: Production of non viral DNA vectors. After some decades of research, development and first clinical approaches to use DNA vectors in gene therapy, cell therapy and DNA vaccination, the requirements for the pharmaceutical manufacturing of gene vectors has improved significantly step b...