EFFECT OF ARTIFICIAL PHOTOPERIODS ON PLASMA THYROXINE-BINDING PREALBUMIN AND RETINOL-BINDING PROTEIN IN JAPANESE QUAIL

1982 ◽  
Vol 92 (2) ◽  
pp. 163-173 ◽  
Author(s):  
D. J. HEAF ◽  
M. EL-SAYED ◽  
B. PHYTHIAN ◽  
J. CARROLL ◽  
J. GLOVER
Keyword(s):  
Japanese Quail ◽  
Binding Protein ◽  
Time Lag ◽  
The Other ◽  
Retinol Binding Protein ◽  
Molar Ratio ◽  
Cyclic Change ◽  
Minimum Level ◽  
Solar Lighting ◽  
Short Days

Variations in thyroxine-binding prealbumin (TBPA) and retinol-binding protein (RBP) concentrations in plasma were determined in Japanese quail subjected to a shortened solar lighting cycle lasting 4 months of real time. The concentration of TBPA varied inversely with the length of daily photoperiod up to 15 h (correlation coefficient r = −0·99) when a minimum level was reached of about 50% of that obtained under short days consisting of 8 h light: 16 h darkness (8L : 16D). A slight reversal in the concentration of TBPA occurred with photoperiods in excess of 16 h. The time-lag in response of the cyclic change in TBPA after the change in the lighting cycle was 8 days. The concentration of holoRBP, on the other hand, showed little change with photoperiods <15 h, but between 15 and 17·5 h it passed through peak values which were 24% and approximately 10% higher than the initial concentrations in female and male birds respectively. Total immunoreactive RBP concentrations in plasma peaked similarly in females but in males the apparent changes were not significant. The molar ratio of the two proteins (TBPA: RBP) which form a 1:1 complex in plasma also changed inversely with photoperiod from 1·6 on short (8L : 16D) to 0·6 on long (16L : 8D) days. When the ratio declined below 1·0 it was noted that rapid growth of the gonads took place and when this ratio returned to > 1·0 regression set in. The changes in plasma TBPA concentration were examined in Japanese quail subjected to sudden changes in photoperiod from short (8L : 16D) to long (20L : 4D) days and vice versa. In the group of birds transferred from short to long days the plasma level declined significantly (P<0·05) within 3 days, whereas birds changed from long to short days were more refractory in that a significant increase was seen only after 30 days. The synthesis of TBPA in liver is closely controlled by photoperiod and it seems that this protein plays an important role in the peripheral distribution of thyroxine and perhaps also influences the cyclical supply of retinol to the gonads.

scholarly journals Serum retinol binding protein 4 is not decreased in congenital generalized lipodystrophy: a case series

2011 ◽  
Vol 55 (4) ◽  
pp. 279-283
Author(s):  
Amélio F. Godoy-Matos ◽  
Rodrigo O. Moreira ◽  
Renata MacDowell ◽  
Izidro Bendet
Keyword(s):  
Adipose Tissue ◽  
Binding Protein ◽  
Case Series ◽  
The Other ◽  
Retinol Binding Protein ◽  
Control Group ◽  
Serum Retinol ◽  
Retinol Binding Protein 4 ◽  
Congenital Generalized Lipodystrophy ◽  
Healthy Control

INTRODUCTION: Previous studies have suggested that Retinol Binding Protein 4 (RPB4), a protein produced by the adipose tissue, is associated with insulin resistance (IR). Congenital Generalized Lipodystrophy (CGL) is a rare disease characterized by IR and paucity of adipose tissue. Our objective was to determine RBP4 levels in patients with CGL. SUBJECTS AND METHODS: Six (6) patients with CGL and a healthy control group were selected to participate in the study. Anthropometric and biochemical variables were compared between groups. RESULTS: No difference was observed in RBP4 levels between the two groups (CGL 42.5 [12.5 - 127] vs. control 57.4 [15.9 - 165]; p = 0.78). On the other hand, leptin levels were significantly lower in CGL patients (CGL 0.65 [0.2 - 0.7] vs. control 10.9 [0.9 - 38.6]; p = 0.015). No correlation was found between RBP-4 and waist circunference (r = 0.18, p = 0.57), or BMI (r = 0.24, p = 0.45). CONCLUSION: RBP4 is not decreased in CGL. These results suggest that adipose tissue may not be the main source of RBP4.

scholarly journals Determination of a Cut-Off Value for the Molar Ratio of Retinol-Binding Protein to Transthyretin (RBP:TTR) in Bangladeshi Patients with Low Hepatic Vitamin A Stores1

2002 ◽  
Vol 132 (12) ◽  
pp. 3687-3692 ◽  
Author(s):  
Francisco J. Rosales ◽  
Kitty K. Chau ◽  
Marjorie H. Haskell ◽  
Anuraj H. Shankar
Keyword(s):  
Vitamin A ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Molar Ratio

scholarly journals Receptor-mediated endocytosis of retinol-binding protein by liver parenchymal cells: interference by radioactive iodination

1993 ◽  
Vol 291 (1) ◽  
pp. 187-191 ◽  
Author(s):  
L Malaba ◽  
G M Kindberg ◽  
K R Norum ◽  
T Berg ◽  
R Blomhoff
Keyword(s):  
Binding Protein ◽  
The Other ◽  
Retinol Binding Protein ◽  
Lag Phase ◽  
Steady Increase ◽  
Release Process ◽  
Liver Parenchymal ◽  
Cell Association ◽  
Higher Temperature ◽  
Parenchymal Cells

Retinol-binding protein (RBP) was iodinated directly by radio-iodine substitution on the tyrosyl residues by the sodium hypochlorite (NaOCl) or the Enzymobead (EB) methods, or indirectly by linkage of 125I-tyramine-cellobiose (TC) or 125I-N-succinimidyl-3-(4- hydroxyphenyl)propionic acid ester (SHPP) adduct on to free amino residues of RBP. Binding, uptake and degradation of iodinated RBP were studied in isolated rat and rabbit liver parenchymal cells. The amount of ligand bound to cells at 4 degrees C was dependent on the type of labelling, in that the 125I-TC ligand was bound to a lesser extent than NaClO-labelled 125I-RBP, EB-labelled 125I-RBP and 125I-SHPP-RBP. At 37 degrees C, the 125I-SHPP-RBP and the EB-labelled 125I-RBP became cell-associated more rapidly than the other two ligands. The higher cell association at 37 degrees C than at 4 degrees C suggests that internalization of the ligand occurred at the higher temperature. The degradation of the ligands was also different. The EB-labelled 125I-RBP, the 125I-TC-RBP and the 125I-SHPP-RBP showed an apparent lag phase before a steady increase in acid-soluble radioactivity was observed. Much less of EB-labelled 125I-RBP and 125I-TC-RBP were degraded (about 6%) than of the other two ligands (about 16%) after 120 min. About 50% of the acid-soluble radioactivity in these experiments could be accounted for by degradation in the medium, suggesting that about half of the degradation observed was intracellular. The present study therefore shows that the different labelling techniques yield varying estimates of the cellular handling of RBP. In addition, a rapid release of RBP was observed in experiments where cells were pulsed with radioactive RBP at 4 degrees C, washed and incubated further at 37 degrees C. Between 50% and 70% was released after 5 min of incubation. By increasing the temperature during the pulse to 37 degrees C, or by lowering the temperature during the chase to 4 degrees C, much less RBP was released from the cells. These data suggest that the release process represents recycling of internalized ligand from an early endosome.

scholarly journals Changes in plasma concentrations of thyroxine binding prealbumin and retinol binding protein in Japanese quail after hatching

1980 ◽  
Vol 44 (3) ◽  
pp. 287-293 ◽  
Author(s):  
D. J. Heaf ◽  
M. El-Sayed ◽  
J. Glover
Keyword(s):  
Japanese Quail ◽  
Total Protein ◽  
Protein Concentration ◽  
Binding Protein ◽  
Plasma Concentrations ◽  
Coturnix Japonica ◽  
Retinol Binding Protein ◽  
Free Access ◽  
Coturnix Coturnix ◽  
Access To Food

1. Male and female Japanese quail (Coturnix coturnix japonica) were reared under short daily photoperiods (8 h light–16 h dark) to inhibit sexual development with free access to food and water. Blood was sampled at frequent intervals for 13 weeks from hatching in order to monitor the developmental changes in plasma concentrations of the two proteins which are important in the transport of retinol, retinol-binding protein (RBP) and thyroxine-binding prealbumin (TBPA).2. Measurements of body-weight, blood packed cell volume and plasma total protein concentration showed that the birds had a normal pattern of growth and haematological development. Plasma concentrations of TBPA, total immunoreactive RBP (IRBP) and holoRBP were 220, 60 and 45 μg/ml respectively in 1-d-old quail and rose to 430, 165 and 140 μg/ml at 14 d of age, which was 10 d after the corresponding change in total protein. Neither RBP nor TBPA concentrations were significantly different between the sexes during the 13 weeks, but there were minor fluctuations in concentration within relatively narrow limits.

Avrupa’ya Türk göçü: Almanya örneği

2014 ◽  
Vol 1 (1) ◽  
pp. 47-56
Author(s):  
Milan Palat
Keyword(s):  
Network Theory ◽  
Quantitative Methods ◽  
Positive Relationship ◽  
Time Lag ◽  
Theoretical Concept ◽  
Living Standards ◽  
The Other ◽  
The European Union ◽  
Effective Mechanism ◽  
The Eu

Bu çalışmanın amacı, Türkiye’den göç ve Almanya’nın ekonomik göstergeleri arasındaki ilişkiyi, nicel metot yöntemleri kullanarak değerlendirmektir. Türkiye’nin belirsiz Avrupa ile bütünleşme beklentilerine rağmen  Avrupa Birliğinin köklü üyelerine olan Türk göçü devam edecektir. Çok sayıda Türk azınlığın yaşadığı ve hayat standartlarının yüksek olduğu Almanya, Hollanda ve Fransa’ya  büyük bir göç dalgası gerçekleşebilir. Çalışmanın istatistiksel bölümünün sonuçları, toplam göç ile gayri safi yurtiçi hasıladaki büyüme arasında pozitif, toplam göç ile işsizlik arasındaki negatif ve tahmin edilen bağımlılık yönüyle uygunluk içerisinde olan toplam göç ile aylık gelir arasında pozitif ilişki olduğunu göstermektedir. Türkiye’den göçle işsizlik arasındaki ilişki, toplam göçle olan ilişkiden daha düşüktür. Ancak, Almanya’daki yabancı mevcudiyeti ile Türkiye’den göç arasında bir ilişki bulunmaktadır. Bu durum, var olan göçmen topluluğunun olduğu yerin, yeni göçmenleri, köken bağlarına dayanarak cezbetmesi ve maliyet- riskler sebebiyle göçün düşük seviye de olduğuna dayanan kuramsal Ağ teorisi görüşü ile uygunluk göstermektedir. Göç ve işsizlik arasında gözlenen ilişki, Almanya’ya göçün  işgücü piyasasında talepte meydana gelen değişime karşılık geldiği gerçeğini göstermektedir. İşsizlik ve göç olgularının meydana geliş zamanlarında bir aralık  olsa bile  göç, Alman emek pazarında var olan dengesizliklerin azaltılmasında nispeten etkili bir mekanizma gibi görünmektedir. ENGLISH TITLE & ABSTRACTTurkish Immigration to the European Union: The Case of GermanyThe objective of the paper was to evaluate the relationships between immigration from Turkey and economic indicators in Germany using  quantitative methods. Despite Turkey’s unclear European integration prospects, it is predicted that Turkish immigration to  established member countries of the EU will continue. The strongest waves may flow to Germany, Netherlands or France, where numerous Turkish minorities are already present and where the living standards are high. Results from the statistical analysis of the paper showed a positive correlation between immigration total and the growth of gross domestic product. On the other hand, a negative correlation of immigration total and unemployment was found and a positive relationship between immigration total and income total which is in agreement with the expected dependency direction. With regards to  immigration from Turkey it is less correlated to unemployment than immigration total. But there is a correlation between immigration from Turkey and the stock of foreigners in Germany This is in accordance with the theoretical concept of network theory where an existing community of migrants keeps attracting new migrants because the costs and risks associated with migration are lower, thanks to established linkages to the country of origin. The observed correlation of migration and unemployment points to the fact that immigration to Germany responds to changes in demand in the labour market. Even though a time lag may occur in the case of unemployment and immigration, migration appears to be a relatively effective mechanism to offset existing imbalances in German labour markets. 

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