Effect of neonatal hypothyroidism on maturation of nuclear triiodothyronine (T3) receptors in developing rat brain

1980 ◽  
Vol 95 (4) ◽  
pp. 495-499 ◽  
Author(s):  
Kazumasa Ishiguro ◽  
Yukichi Suzuki ◽  
Tamotu Sato

Abstract. Changes of nuclear T3 receptors during brain maturation were studied in normal and hypothyroid rats. In normal rats, the higher receptor concentration present in the neonatal period (0.35 ± 0.04 ng T3/mg DNA) decreased at the age of 14 days (0.25 ± 0.02 ng T3/mg DNA), and remained at this level thereafter to 35 days of age (0.25 ± 0.03 T3/mg DNA). In contrast, hypothyroid rats showed a significantly higher concentration than that found in an age-matched control group at the age of 14 days (0.38 ± 0.07 ng T3/mg DNA), and maintained this level up to 35 days of age (0.37 ± 0.03 T3/mg DNA). The binding affinity was similar in both groups and throughout maturation (mean ± sd in normal groups: 1.9 ± 0.3 × 1010m−1, in hypothyroid groups: 1.7 ± 0.2 × 1010m−1). Plasma T3 concentrations showed changes reciprocal to those in the binding capacity of T3 receptors. These results indicate that nuclear T3 receptors in rat brain mature by the age of 14 days, in association with a decrease in binding capacity, and this process seems to be T3-dependent. The physiological role of the high concentration of T3 receptors observed in neonatal and hypothyroid rat brain during development is at present not clear.

1985 ◽  
Vol 5 (8) ◽  
pp. 643-648 ◽  
Author(s):  
Anjana Mazumder ◽  
Kamal Das ◽  
Pranab K. Sarkar

The effect of T3 (triiodothyronine) on the induction of tubulin in hypothyroid developing rat brain has been examined using organ cultures of brains from late fetal, neonatal and postnatalrats. The neonatal brain displayed maximum sensitivity to T3. Hypothyroidism resulted in a 26% decline in the level of tubulin in the neonatal brain as opposed to a 5–15% decline in the fetal or postnatal brain. Exposure of the hypothyroi d neonatal brain to T3 for 2 h in culture led to a 61% rise in the level of tubulin in contrast to a 41% increase seen in the case of normal brain. Total protein synthesis was not significantly affected. The preferential decline of tubulin in the neonatal hypothyroid brain, its enhanced sensitivity to T3 compared to normal brain, and the coincidence of the period of sensitivity to that of brain maturation indicate that the regulation of the level of tubulin by T3 in the developing brain is a natural ontogenic phenomenon.


1979 ◽  
Vol 182 (2) ◽  
pp. 367-370 ◽  
Author(s):  
W A Maltese ◽  
J J Volpe

The specific activity of 3-hydroxy-3-methylglutaryl-CoA reductase increases when homogenates of developing rat brain are incubated at 37 degrees C or kept on ice. This increase is completely blocked by the addition of F- to the homogenization medium and the assay mixture. The capacity for activation of the reductase is greatest during the early postnatal period and declines as brain maturation proceeds. The data suggest that catalytic modification of the reductase may play a role in the regulation of cholesterol synthesis in the developing brain.


2021 ◽  
Vol 38 (5) ◽  
pp. 115-122
Author(s):  
Kazim G. Gasanov ◽  
Viktor A. Zurnadzhyants ◽  
Eldar A. Kchibekov ◽  
M. I. Shikhragimov

Objective. To determine the blood serum 2-microglobulin and 2-macroglobulin concentration in patients undergoing renal replacement therapy (programmed hemodialysis) for the diagnosis of uremic pancreatitis and / or destructive pancreatitis. Materials and methods. The study involved 52 patients admitted to the Surgical Unit of Astrakhan "RZhD-Medicine" Hospital and City Clinical Hospital № 3. The blood serum 2-microglobulin and 2-macroglobulin concentration was analyzed in patients admitted on an emergency basis with suspicion of uremic pancreatitis and destructive pancreatitis, who receive renal replacement therapy (programmed hemodialysis). The control group included 50 outpatients undergoing renal replacement therapy (programmed hemodialysis). The study did not include patients with suspected pancreatitis who were not receiving renal replacement therapy. The period of the study is 20192021. Results. The concentration of blood serum 2-microglobulin is statistically higher than normal in all patients, who had received renal replacement therapy (programmed hemodialysis) in anamnesis. The most statistically high concentration of 2-microglobulin was revealed while studying patients with uremic pancreatitis (n = 34), and was (30.0 2.75 mg/l) compared with the blood serum concentration in patients with destructive pancreatitis (8 0.51 mg / l). The concentration of 2-macroglobulin was statistically lower in destructive pancreatitis (n = 18) and was 615 161 mg/l compared with uremic pancreatitis (980 216 mg/l). In the control group of outpatients (n = 50) receiving renal replacement therapy (programmed hemodialysis), no statistically significant blood serum concentrations of 2-microglobulin and 2-macroglobulin were found. Conclusions. A clear dependence of the concentration of 2-microglobulin and 2-macroglobulin on the severity of uremic pancreatitis and destructive pancreatitis was established. Statistically high values of 2-microglobulin concentrations were obtained in patients with uremic pancreatitis, and the 2-macroglobulin level was statistically low in destructive pancreatitis.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Camille Dumon ◽  
Yasmine Belaidouni ◽  
Diabe Diabira ◽  
Suzanne M. Appleyard ◽  
Gary A. Wayman ◽  
...  

Abstract The canonical physiological role of leptin is to regulate hunger and satiety acting on specific hypothalamic nuclei. Beyond this key metabolic function; leptin also regulates many aspects of development and functioning of neuronal hippocampal networks throughout life. Here we show that leptin controls chloride homeostasis in the developing rat hippocampus in vitro. The effect of leptin relies on the down-regulation of the potassium/chloride extruder KCC2 activity and is present during a restricted period of postnatal development. This study confirms and extends the role of leptin in the ontogenesis of functional GABAergic inhibition and helps understanding how abnormal levels of leptin may contribute to neurological disorders.


1966 ◽  
Vol 13 (10) ◽  
pp. 1017-1025 ◽  
Author(s):  
Alicia E. Ramírez De Guglielmone ◽  
Carlos J. Gómez

2020 ◽  
Author(s):  
Camille Dumon ◽  
Yasmine Belaidouni ◽  
Diabe Diabira ◽  
Suzanne Appleyard ◽  
Gary Wayman ◽  
...  

Abstract The canonical physiological role of leptin is to regulate hunger and satiety acting on specific hypothalamic nuclei. Beyond this key metabolic function; leptin also regulates many aspects of development and functioning of neuronal hippocampal networks throughout life. Here we show that leptin controls chloride homeostasis in the developing rat hippocampus in vitro. The effect of leptin relies on the down-regulation of the potassium/chloride extruder KCC2 activity and is present during a restricted period of postnatal development. This study confirms and extends the role of leptin in the ontogenesis of functional GABAergic inhibition and helps understanding how abnormal levels of leptin may contribute to neurological disorders.


2017 ◽  
Vol 17 (3) ◽  
pp. 106-117 ◽  
Author(s):  
Imene Benyettou ◽  
Omar Kharoubi ◽  
Nouria Hallal ◽  
Hadj Ali Benyettou ◽  
Kaddour Tair ◽  
...  

2001 ◽  
Vol 77 (4) ◽  
pp. 1085-1096 ◽  
Author(s):  
Annabelle Reaux ◽  
Nadia De Mota ◽  
Ivana Skultetyova ◽  
Zsolt Lenkei ◽  
Said El Messari ◽  
...  
Keyword(s):  

1983 ◽  
Vol 104 (4) ◽  
pp. 485-489 ◽  
Author(s):  
Alfredo R. Recúpero ◽  
Aldo H. Coleoni ◽  
Olga Cherubini ◽  
Adriana Oviedo

Abstract. Glucocorticoid deficit in rats induced by adrenalectomy for a 10-day period resulted in an increase in the apparent association constant (Ka) of the liver nuclear T3-receptor while maximal binding capacity (MBC) remained unaltered compared to the intact (sham-operated) animals and to adrenalectomy plus dexamethasone (Sx + D) animals. In addition, a significant increase in the basal activity of liver mitochondrial α-glycerophosphate dehydrogenase (α-GPD) was observed, while cytosolic malic enzyme (ME) activity was not modified in this situation. Dexamethasone injection (5 mg/kg/day for 4–5 days) to previously adrenalectomized animals (Sx + D) induced a significant increase in MBC of nuclear T3-receptors. On the other hand, Ka value and α-GPD activity were restored to the values found in the control group. However, basal activity of ME as well as the response of this enzyme to a saturating dose of T3 was substantially increased by dexamethasone treatment. A non-specific in vitro effect of dexamethasone on MBC and ME was excluded as these parameters were not modified when dexamethasone was added immediately before the in vitro assays. The present study indicates that glucocorticoid deficit or excess is able to induce changes at the level of the nuclear T3-receptor site. The increase in the activity of cytolic ME induced by dexamethasone injection was associated with a simultaneous


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