Incorporation of Thyroxin Carbon in Protein Fractions of<i>Rana catesbiana</i>Tadpole Nervous System, Liver and Tail

Dratman, Mary B.; Richter, Mabel E.; Lynch, Helen A.

doi:10.1210/endo-86-2-217

Cited by 22 publications

(5 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fractional rate of disappearance of NEI from plasma and tissue was extremely slow in comparison to the initial fractional metabolic removal of exchangeable T4 and T3. In previous studies we have reported [4][5][6][7]. In this experiment T3-15I only was injected in animals sacrificed 1, .2, and 4 days after injection, but both T3-OI and T4-'1I were injected in the animals sacrificed on days 6, 11, and 20.…”

Section: Resultsmentioning

confidence: 92%

See 1 more Smart Citation

Slow fractional removal of nonextractable iodine from rat tissue after injection of labeled l-thyroxine and 3,5,3′-triiodo-l-thyronine

Oppenheimer¹,

Surks²,

Schwartz³

1972

J. Clin. Invest.

View full text Add to dashboard Cite

A B S T R A C T Previous studies have shown that a small but significant proportion of radioiodine from labeled L-thyroxine (T4) and 3,5,3'-triiodo-L-thyronine (Ts) is incorporated into plasma and tissue proteins and is not, therefore, extractable with ethanol or other organic solvents. Other studies have shown that the complex consists, at least in part, of the iodothyronine in apparent covalent linkage with protein. In the present series of experiments the disappearance rate of nonextractable iodine (NEI) was determined in plasma, liver, and kidney after the injection of rats with a single dose of T4 and Ts labeled with radioiodine in the phenolic ring.The ti of NEI decay was substantially longer than the tj of the initial metabolic removal of T4 (16 hr) and Ts (4-6 hr). Thus, between days 3 and 11 the average tj of plasma NEI derived from T4 was 2.2 days, from T3, 1.9 days; kidney NEI from T4, 7.4 days, from Ts, 6.1 days; hepatic NEI from T4, 4.3 days, from Ts, 5.2 days.The slow disappearance of liver NEI was of special interest in connection with an analysis of previously published data by Tata and associates dealing with the sequential tissue effects after the injection of a single dose of Ts into thyroidectomnized rats. The tj of decay of the various biological effects measured, primarily in the liver, appeared similar to each other, averaging between 4 and 6 days. jected with 25 iyg of T3) was found to be 4.5 days. The coincidence in the slow fractional disappearance rates of hepatic NEI and the dissipation of hormonal tissue effects raises the distinct possibility that T3 interacts with specific cellular receptor sites to form covalent complexes which are slowly removed and serve both to initiate and to perpetuate hormonal action. A mathematical analysis of hormonal reaction mechanisms, based on the assumption of a linearly responsive system, a tA of Ts of 4 hr, and a tj of 4.5 days for the postulated long-lived "messenger" suggests that maximal expression of hormonal activity cannot be attained before 20 hr after the injection of a hormone pulse. This value is broadly consonant with the observed data accumulated by Tata and associates. The existence of a long-lived messenger, possibly a species of NEI, would therefore explain not only the slow dissipation of hormonal effects but also the wellrecognized "lag-time" in the expression of hormonal action.Efforts were also made to define the relationship between extractable and nonextractable radioactivity in the plasma and tissue samples analyzed. The ratio of extractable radioactivity in plasma to extractable radioactivity in tissue became constant shortly after the injection of T8 and T4. The fractional disappearance of extractable radioactivity showed a progressive slowing over the course of the first 10 days after the injection. The distribution of extractable radioactivity between plasma and tissues was compatible with the known partition of exchangeable To and Ts. In the case of Ts, di- 2796The Journal of Clinical Investigation Volume 51 November 1972 ...

show abstract

Section: Resultsmentioning

confidence: 92%

“…This moiety has been designated "nonextractable iodine" (NEI) and appears to consist, at least in part, of a covalent complex between iodothyronine molecules and protein (3,4).…”

Section: Introductionmentioning

confidence: 99%

Slow fractional removal of nonextractable iodine from rat tissue after injection of labeled l-thyroxine and 3,5,3′-triiodo-l-thyronine

Oppenheimer¹,

Surks²,

Schwartz³

1972

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

“…The extracts were prepared for paper chromatography after neutralization with HC104, centrifugation, and application on Whatman 3MM paper according to Dratman et at. (14). The results in Table 1 show that most of the labeled material has an RF value similar to the standard unlabeled and radioactive thyroxine.…”

Section: Methodsmentioning

confidence: 86%

Temperature-Dependent Intracellular Distribution of Thyroxine in Amphibian Liver

Griswold

Fischer

Cohen

1972

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Rana catesbeiana tadpoles were injected with [14Cjthyroxine, and the subeellular distribution of the labeled hormone was determined. At 250 the amount of isotope found in the liver was maximal after 1-2 hr and then rapidly decreased to a relatively constant value. A large percentage of the hormone was found associated with the purified nuclei isolated 24 hr after injection of ["Cithyroxine. Injection of ['4Cjthyroxine into tadpoles maintained at 50 resulted in a much slower but constant accumulation of isotope in the liver, with virtuallyno movement of thyroxine into the cell nucleus. Thyroxine was bound very tightly to the chromatin fraction of the nucleus, but extraction and chromatography revealed no chemical modification of the thyroxine itself. These results suggest the presence of two temperature-dependent processes: one concerned with the transport of thyroxine into the liver cell and a second concerned with the transport of the intracellular thyroxine into the-cell nucleus. It is proposed that the latter process is involved in the lowtemperature inhibition of thyroxine-induced metamorphosis.The consequences of the action of thyroxine in amphibian liver tissue are similar to those of the action of steroid hormones on their respective target tissues in that RNA polymerase activity is increased, the RNA product is altered both qualitatively and quantitatively, and eventually de novo protein synthesis results (1-4). The action of steroid hormones on their target tissues involves intracellular receptor proteins that strongly and specifically bind the hormone and transport it into the nucleus, where the hormone-receptor complex interacts with components of the chromatin (5, 6). For rat uterus treated with estrogen this transport to the nucleus appears to be a temperature-dependent process (S, 5). In contrast, very little is known about the intracellular transport of thyroxine or the ultimate subcellular target of the hormone in amphibians.The induction of amphibian metamorphosis by exogenous thyroxine exhibits a very pronounced low-temperature inhibition (2, 7). Tadpoles treated with thyroxine and maintained for months at 50 will show no response to the hormone (2). If at any time during this period the water temperature is raised to 250, a response is apparent with a very short lag phase (2). The mechanism involved in this temperature sensitivity and the nature of its reversibility are unknown. The change from 25 to 5' has little effect on total protein and RNA synthesis in the tadpole (8). The experiments on Rana catesbeiana liver reported here indicate that a hormone-transport process may be involved in this temperature sensitivity, and suggest that the initiation of metamorphosis is dependent on the movement of thyroid hormone into the cell nucleus. MATERIALS AND METHODSTadpoles of Taylor-Kollros stages XII-XIV (9) were divided into two groups, one of which was maintained for 24 hr at 25°a nd the other at 5°. After the animals were maintained at the respective temperatures, each tadpole was inject...

show abstract

“…skin) are difficult to breakdown nonenzymatically. However, there is evidence in amphibians and mammals, that enzymatic digestion may liberate iodomaterials from protein compounds into which they have been covalently incorporated (Dratman et al 1970;Surks and Oppenheimer 1970). These iodomaterials were found in homogenates after alcohol extractions were performed and were therefore termed non-extractable iodide (NEI).…”

Section: Discussionmentioning

confidence: 99%

Determination of 3,5,3′-triiodo-L-thyronine (T3) levels in tissues of rainbow trout (Salmo gairdneri) and the effect of low ambient pH and aluminum

Fok

Eales

Brown

1990

Fish Physiol Biochem

View full text Add to dashboard Cite

Tissue T3 (3,5,3'-triiodo-L-thyronine) concentrations were measured in rainbow trout, Salmo gairdneri, after digestion by Pronase or collagenase and extraction with ethanolic ammonia (99:1, v/v) followed by 2N NH4OH and chloroform. Recoveries of [(125)I]T3 administered in vivo or in vitro were high and consistent and there was close parallelism between sample dilutions and the radioimmunoassay curve, but recoveries of unlabeled T3 administered in vitro were low and variable. Alternatively, trout were brought to isotopic equilibrium by [(125)I]T3 infusion for 96 h, the extracted [(125)I]T3 determined by gel filtration and the tissue T3 content calculated from the specific activity of plasma [(125)I]T3. By the latter method, tissue T3 concentrations were: intestine (4.2 ng/g), kidney (2.5), liver (2.8), stomach (1.5), heart (1.0), muscle (0.7), gill (0.6) and skin (0.3). Muscle (67% of body weight) comprised the largest tissue T3 pool (82% of all tissues examined). Seven days exposure of trout to water acidified with H2SO4 (pH 4.8) or acidified water containing aluminum (21.6 mM), decreased tissue T3 content generally and particularly in muscle (14% of controls). In conclusion, skeletal muscle is the largest T3 tissue pool and seems highly responsive to altered physiologic state.

show abstract

Incorporation of Thyroxin Carbon in Protein Fractions ofRana catesbianaTadpole Nervous System, Liver and Tail

Cited by 22 publications

References 1 publication

Slow fractional removal of nonextractable iodine from rat tissue after injection of labeled l-thyroxine and 3,5,3′-triiodo-l-thyronine

Slow fractional removal of nonextractable iodine from rat tissue after injection of labeled l-thyroxine and 3,5,3′-triiodo-l-thyronine

Temperature-Dependent Intracellular Distribution of Thyroxine in Amphibian Liver

Determination of 3,5,3′-triiodo-L-thyronine (T3) levels in tissues of rainbow trout (Salmo gairdneri) and the effect of low ambient pH and aluminum

Contact Info

Product

Resources

About