COMPARISON OF THE EFFECT OF HYPOPHYSECTOMY AND THYROXINE ADMINISTRATION ON THYROID FUNCTION IN THE RAT<sup>1</sup>

Yamada, Takashi; Uno, Satoru; Greek, Monte A.

doi:10.1210/endo-69-1-1

Cited by 24 publications

(5 citation statements)

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“…Only fragmentary quantitative data are available for other organs and tissues. A possible exception to the temporal dissociation between plasma hormone concentration and tissue effect is the pituitary which on the basis of limited published data appears to be rapidly responsive to changes in the plasma hormone (28). It is possible that a mechanism other than NEI formation is involved in shutting off thyroid-stimulating hormone (TSH) secretion by pituitary.…”

Section: Resultsmentioning

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.

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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 ...

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Section: Resultsmentioning

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.

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“…It is also claimed that the pituitary secretion of thyroid-stimulating hormone (TSH) is not accelerated despite a significant reduction of total and free T3 levels in patients with liver cirrhosis (7). This finding is incompatible with the hypothalamus-pituitarythyroid feedback theory (8).…”

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confidence: 99%

Thyroid Hormone Metabolism in Patients with Liver Cirrhosis, as Judged by Urinary Excretion of Triiodothyronine

Aizawa

Yamada

Tawata

et al. 1980

J American Geriatrics Society

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This study included 35 patients with liver cirrhosis, 23 patients with hyperthyroidism, 12 with hypothyroidism, and 2 with other endocrine disorders. In the various endocrine disorders an appreciable amount of triiodothyronine (T3) was excreted into the urine but the daily excretion was fairly constant in each patient. Urinary excretion of T3 was negligible or depressed in hypothyroidism, but increased with a rise in the serum level of T3. Serum and urinary T3 decreased in liver cirrhosis, but the serum thyroxine (T4) level was within the normal range. When the cirrhosis patients were divided into 3 groups according to the urinary excretion of T3, a decrease of urinary T3 was associated with a decrease in the serum levels of T3 and free T3. An increase of serum thyroid-stimulating hormone (TSH) either before or after injection of thyrotropin-releasing hormone (TRH) was inversely correlated with a decrease of serum and urinary T3. The decrease of serum and urinary T3 was correlated with the magnitude of lh a decrease in the serum levels of T3 and free T3. An increase of serum thyroid-stimulating hormone (TSH) either before or after injection of thyrotropin-releasing hormone (TRH) was inversely correlated with a decrease of serum and urinary T3. The decrease of serum and urinary T3 was correlated with the magnitude of lh a decrease in the serum levels of T3 and free T3. An increase of serum thyroid-stimulating hormone (TSH) either before or after injection of thyrotropin-releasing hormone (TRH) was inversely correlated with a decrease of serum and urinary T3. The decrease of serum and urinary T3 was correlated with the magnitude of liver damage as judged by indocyanine green retention and a decreased urinary excretion of cyclic adenosine 3',5'-monophosphate. In vitro experiments indicated that rat liver, as compared to the kidney, heart and skeletal muscle, strongly converts T4 to T3, but this activity is greatly reduced by liver damage induced by ligation of the bile duct. It is suggested that patients with liver cirrhosis are, to some extent, in a state resembling subclinical hypothyroidism because of inability of the liver to metabolize a sufficient amount of T3 from T4.

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“…Hypophysectomy or thyroxine administration has been known to induce similar hypofunctionally morphological changes in the thyroid gland (YAMADA et al, 1961). As reported by many investigators (DEMPSEY and PETERSON, 1955;WETZEL et al, 1965;SELJELID, 1967;FUJITA and SUEMASA, 1968;SELJELID et al, 1971;BJORKMAN et al, 1974;GALL et al, 1976), the thyroids of hypophysectomized or thyroxine-treated animals become extremely small in size, the follicle lumina are enlarged, and the follicle epithelial cells are attenuated.…”

Section: Discussionmentioning

confidence: 78%

Three-dimensional imaging of blood vessels in thyroids from normal and levothyroxine sodium-treated rats.

Imada

Kurosumi

Fujita

1986

Arch. Histol. Jap., Arch. Histol. Jpn

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COMPARISON OF THE EFFECT OF HYPOPHYSECTOMY AND THYROXINE ADMINISTRATION ON THYROID FUNCTION IN THE RAT¹

Cited by 24 publications

References 0 publications

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

Thyroid Hormone Metabolism in Patients with Liver Cirrhosis, as Judged by Urinary Excretion of Triiodothyronine

Three-dimensional imaging of blood vessels in thyroids from normal and levothyroxine sodium-treated rats.

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COMPARISON OF THE EFFECT OF HYPOPHYSECTOMY AND THYROXINE ADMINISTRATION ON THYROID FUNCTION IN THE RAT1

Cited by 24 publications

References 0 publications

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

Thyroid Hormone Metabolism in Patients with Liver Cirrhosis, as Judged by Urinary Excretion of Triiodothyronine

Three-dimensional imaging of blood vessels in thyroids from normal and levothyroxine sodium-treated rats.

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COMPARISON OF THE EFFECT OF HYPOPHYSECTOMY AND THYROXINE ADMINISTRATION ON THYROID FUNCTION IN THE RAT¹