The Effect of Maternal Hypothyroidism on Maternal and Fetal Tissue Glucose-1-&lt;sup&gt;14&lt;/sup&gt;C Incorporation in Rats

Porterfield, Susan P.; Hendrich, C. E.

doi:10.1159/000178697

Cited by 13 publications

(11 citation statements)

References 12 publications

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“…In fact, we have demonstrated previously a partial alleviation of the hypoglycemia and tissue glycogen deficits in the fetuses ofTx mothers by GH administration to these Tx mothers (34)(35)(36). Also amino acid transport, amino acid utilization, and total protein content of tissues are to a great extent normalized in the fetuses of GH-treated Tx mothers (21,22).…”

Section: Discussionmentioning

confidence: 79%

Serum Growth Hormone Levels in Hypothyroid and GH-Treated Thyroidectomized Rats and Their Progenies

Hendrich

Porterfield

1992

Experimental Biology and Medicine

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Growth hormone (GH) was measured in the sera of control, hypothyroid (thyroidectomized [Tx]) and GH-treated Tx rats and their fetuses on Days 19, 20, 21, and 22 of gestation and in their progenies on postnatal Days 1, 5, 30, and 75. Maternal endogenous serum GH increased dramatically between the 19th and 20th days of gestation and remained elevated through the 22nd day in control rats, but was depressed significantly in Tx and GH-treated Tx rats during this period. GH was not always detected in the sera of 19-day-old fetuses. On Day 20, GH was depressed in fetuses of Tx mothers as compared with those form controls or GH-treated Tx mothers. GH was elevated in sera of fetuses from GH-treated Tx rats over fetuses of control and Tx only rats on the 22nd day of gestation. In postnatal rats, those from GH-treated mothers continued to show elevated serum GH on Day 1 as compared with those from Tx only mothers. On postnatal Days 5 and 30, progenies of Tx mothers had significantly elevated GH as compared with progenies of control mothers. At 75 days of age, the GH levels of these progenies had normalized. We have shown previously that the hormonal secretions of the pituitary-thyroid axis are badly disrupted in the progenies of Tx and GH-treated Tx mothers and that even as adults these animals have tissue (brain and liver) deficits of active thyroid hormones. Although the onset of GH secretion is mildly delayed in fetuses of Tx but not GH-treated Tx mothers, the serum GH levels of both groups of progenies are elevated during most of the neonatal period through the time of puberty. It is, therefore, concluded that GH in the absence of adequate levels of thyroid hormones is ineffective in preventing many of the learning and memory deficits induced in the progenies of Tx mothers.

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Section: Discussionmentioning

confidence: 79%

Serum Growth Hormone Levels in Hypothyroid and GH-Treated Thyroidectomized Rats and Their Progenies

Hendrich

Porterfield

1992

Experimental Biology and Medicine

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“…Hypothyroid rats have prolonged gestation, and fetal and neonatal mortality is nearly 50% (136,137). Fetuses and pups are smaller and appear to be biochemically and developmentally immature (137,138).…”

Section: Maternal Thyroid Hormones and Fetal Developmentmentioning

confidence: 99%

The Role of Thyroid Hormones in Prenatal and Neonatal Neurological Development—Current Perspectives

PORTERFIELD,

HENDRICH

1993

Endocrine Reviews

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296

276

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“…The fetuses, neonates, and adult progenies of Tx-only mo thers also have numerous metabolic abnormalities. The fe tuses are hypoglycemic, have tissue glycogen deficits [36], and their utilization of l4C-labeled glucose is abnormal [31 ]. Brain and liver RNA and DNA developmental patterns are altered [35] and myelinization in brain is delayed [34] in these animals as compared to control offspring.…”

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confidence: 98%

Behavioral Testing of Progenies of Tx (Hypothyroid) and Growth Hormone-Treated Tx Rats: An Animal Model for Mental Retardation

Hendrich

Jackson

Porterfield³

1984

Neuroendocrinology

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Virgin Sprague-Dawley Holtzman rats were rendered Tx (hypothyroid) by radiothyroidectomy and maintained on 1.0 µg T4 (thyroxine) per 100 g BW until pregnant. One-half of these Tx animals were administered 0.5 IU of growth hormone (GH) during the last 10–11 days of gestation as GH secretion is especially deficient in Tx rats. Untreated, food restricted to the level consumed by the Tx-only rats, GH-treated euthyroid, and T4-treated until pregnant animals served as controls. The animals were allowed to go through parturition and each litter was reduced to no more than 6 pups by removing pups for tissue weights and protein analyses at 1 and 5 days of age. The pups were weaned at 22 days of age and 2 animals per litter were utilized for behavioral testing between 40 and 60 days of age. At the end of the behavioral testing period the 60-day-old offspring were sacrificed to obtain tissue weights and protein concentrations. The behavioral tests were based on the ability of the animals to learn a Lashley’s type 3 enclosed alley maze and their spontaneous activity was measured in stabilimeter cages. The animals were fasted overnight on alternate days and then given a food reward upon traversing the maze. This allowed for 10 separate trials in both the Lashley maze and the stabilimeters over the 20-day period from 40 to 60 days of age. Our previous studies have shown the fetuses and progenies of Tx-only mothers to have multiple metabolic defects including reduced rates of protein synthesis and tissue protein concentrations. The Tx mothers have poor reproductive performance and the surviving fetuses and early neonates are growth stunted. GH treatment of the Tx mother, during the latter part of gestation, corrects some of these parameters in their offspring. The progenies of Tx mothers used in this study were typical of those of our previous reports. The numbers of live 1 -day-old neonates, their body, brain, and liver weights were significantly reduced as compared to controls. Brain, liver, and serum protein concentrations were significantly depressed in 1, 5-, and 60-day-old offspring of Tx-only mothers as compared to those of GH-treated and offspring of the various control group mothers. These offspring of Tx-only mothers showed a total inability to learn the Lashley maze. None of the offspring of Tx-only mothers were able to traverse the maze on consecutive trials without committing errors as compared to 25–42% of the progenies of the control groups which learned the maze before the end of 10 trials. The time required, for the offspring of all maternal groups, to traverse the maze to obtain a food reward decreased significantly. However, the offspring of Tx-only mothers, even though they would try to traverse the maze rapidly, took significantly longer to traverse the maze than progenies of the control groups in trials 6–10 because of the errors committed. These same offspring of the Tx-only mothers had also significantly increased spontaneous movements in the stabilimeter cages as compared to progenies of control mothers...

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The Effect of Maternal Hypothyroidism on Maternal and Fetal Tissue Glucose-1-<sup>14</sup>C Incorporation in Rats

Cited by 13 publications

References 12 publications

Serum Growth Hormone Levels in Hypothyroid and GH-Treated Thyroidectomized Rats and Their Progenies

Serum Growth Hormone Levels in Hypothyroid and GH-Treated Thyroidectomized Rats and Their Progenies

The Role of Thyroid Hormones in Prenatal and Neonatal Neurological Development—Current Perspectives

Behavioral Testing of Progenies of Tx (Hypothyroid) and Growth Hormone-Treated Tx Rats: An Animal Model for Mental Retardation

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