Effects of Prenatal Maternal TRH Stimulation on the Postnatal Ability of Neonatal Piglets to Cope with a Cold Challenge

Neonatology ◽  
1998 ◽  
Vol 73 (6) ◽  
pp. 395-403
Author(s):  
A. Finsten ◽  
A. Donald ◽  
L.A. Bate
1972 ◽  
Vol 70 (1) ◽  
pp. 196-208 ◽  
Author(s):  
Bengt Karlberg ◽  
Sven Almqvist

ABSTRACT The effects of the administration of normal saline in four normal subjects and the single iv injections of synthetic pyroglutamyl-histidyl-proline amide (TRH) in doses of 6.25, 12.5, 25, 50, 100, 200 and 400 μg in 12 healthy subjects were evaluated by clinical observations and serial measurements from −10 to + 360 minutes of serum TSH, PBI, STH, cholesterol, glucose and insulin. Normal saline and TRH 6.25 μg iv did not change the serum TSH level. The minimum iv dose of TRH increasing serum TSH within 10 minutes was 12.5 μg. Nine of 12 subjects gave maximal increases of serum TSH after TRH 100 μg and all after 200 and 400 μg. The time for the peak response varied with the dose from 15 to 60 minutes. The dose-response curves, average and individual, were complex and not linear. This was interpreted as a varying degree of stimulation of both pituitary synthesis and release of TSH by TRH. PBI changes were measured at 2 h and 6 h. Minimum dose for a significant increase of PBI was 12.5 μg and 6.25 μg of TRH for the respective times. No change in basal STH-levels occurred in 53 of 65 TRH-stimulation tests. Nine of the 12 changes in serum STH occurred in four subjects with varying basal STH-levels. No changes were found in serum cholesterol, glucose or insulin. Our results show that 50 μg of TRH can be used as a standard dose for the single iv stimulation of pituitary release of TSH. TRH stimulated both TSH and STH release in 18% of our tests.


2019 ◽  
Vol 317 (5) ◽  
pp. E839-E851 ◽  
Author(s):  
Jane K. Naberhuis ◽  
Agus Suryawan ◽  
Hanh V. Nguyen ◽  
Adriana Hernandez-Garcia ◽  
Stephanie M. Cruz ◽  
...  

Postnatal growth of lean mass is commonly blunted in preterm infants and may contribute to short- and long-term morbidities. To determine whether preterm birth alters the protein anabolic response to feeding, piglets were delivered at term or preterm, and fractional protein synthesis rates (Ks) were measured at 3 days of age while fasted or after an enteral meal. Activation of signaling pathways that regulate protein synthesis and degradation were determined. Relative body weight gain was lower in preterm than in term. Gestational age at birth (GAB) did not alter fasting plasma glucose or insulin, but when fed, plasma insulin and glucose rose more slowly, and reached peak value later, in preterm than in term. Feeding increased Ks in longissimus dorsi (LD) and gastrocnemius muscles, heart, pancreas, and kidney in both GAB groups, but the response was blunted in preterm. In diaphragm, lung, jejunum, and brain, feeding increased Ks regardless of GAB. Liver Ks was greater in preterm than term and increased with feeding regardless of GAB. In all tissues, changes in 4EBP1, S6K1, and PKB phosphorylation paralleled changes in Ks. In LD, eIF4E·eIF4G complex formation, phosphorylation of TSC2, mTOR, and rpS6, and association of mammalian target of rapamycin (mTOR1) complex with RagA, RagC, and Rheb were increased by feeding and blunted by prematurity. There were no differences among groups in LD protein degradation markers. Our results demonstrate that preterm birth reduces weight gain and the protein synthetic response to feeding in muscle, pancreas, and kidney, and this is associated with blunted insulin- and/or amino acid-induced translation initiation signaling.


Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 410 ◽  
Author(s):  
Kristine Bach Korsholm Knudsen ◽  
Christine Heerup ◽  
Tine Røngaard Stange Jensen ◽  
Xiaolu Geng ◽  
Nikolaj Drachmann ◽  
...  

Efficient lipid digestion in formula-fed infants is required to ensure the availability of fatty acids for normal organ development. Previous studies suggest that the efficiency of lipid digestion may depend on whether lipids are emulsified with soy lecithin or fractions derived from bovine milk. This study, therefore, aimed to determine whether emulsification with bovine milk-derived emulsifiers or soy lecithin (SL) influenced lipid digestion in vitro and in vivo. Lipid digestibility was determined in vitro in oil-in-water emulsions using four different milk-derived emulsifiers or SL, and the ultrastructural appearance of the emulsions was assessed using electron microscopy. Subsequently, selected emulsions were added to a base diet and fed to preterm neonatal piglets. Initially, preterm pigs equipped with an ileostomy were fed experimental formulas for seven days and stoma output was collected quantitatively. Next, lipid absorption kinetics was studied in preterm pigs given pure emulsions. Finally, complete formulas with different emulsions were fed for four days, and the post-bolus plasma triglyceride level was determined. Milk-derived emulsifiers (containing protein and phospholipids from milk fat globule membranes and extracellular vesicles) showed increased effects on fat digestion compared to SL in an in vitro digestion model. Further, milk-derived emulsifiers significantly increased the digestion of triglyceride in the preterm piglet model compared with SL. Ultra-structural images indicated a more regular and smooth surface of fat droplets emulsified with milk-derived emulsifiers relative to SL. We conclude that, relative to SL, milk-derived emulsifiers lead to a different surface ultrastructure on the lipid droplets, and increase lipid digestion.


Author(s):  
Longmin Chen ◽  
Jing Zhang ◽  
Yuan Zou ◽  
Faxi Wang ◽  
Jingyi Li ◽  
...  

AbstractKdm2a catalyzes H3K36me2 demethylation to play an intriguing epigenetic regulatory role in cell proliferation, differentiation, and apoptosis. Herein we found that myeloid-specific knockout of Kdm2a (LysM-Cre-Kdm2af/f, Kdm2a−/−) promoted macrophage M2 program by reprograming metabolic homeostasis through enhancing fatty acid uptake and lipolysis. Kdm2a−/− increased H3K36me2 levels at the Pparg locus along with augmented chromatin accessibility and Stat6 recruitment, which rendered macrophages with preferential M2 polarization. Therefore, the Kdm2a−/− mice were highly protected from high-fat diet (HFD)-induced obesity, insulin resistance, and hepatic steatosis, and featured by the reduced accumulation of adipose tissue macrophages and repressed chronic inflammation following HFD challenge. Particularly, Kdm2a−/− macrophages provided a microenvironment in favor of thermogenesis. Upon HFD or cold challenge, the Kdm2a−/− mice manifested higher capacity for inducing adipose browning and beiging to promote energy expenditure. Collectively, our findings demonstrate the importance of Kdm2a-mediated H3K36 demethylation in orchestrating macrophage polarization, providing novel insight that targeting Kdm2a in macrophages could be a viable therapeutic approach against obesity and insulin resistance.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Katharina Metzger ◽  
Dirk Dannenberger ◽  
Armin Tuchscherer ◽  
Siriluck Ponsuksili ◽  
Claudia Kalbe

Abstract Background Climate change and the associated risk for the occurrence of extreme temperature events or permanent changes in ambient temperature are important in the husbandry of farm animals. The aim of our study was to investigate the effects of permanent cultivation temperatures below (35 °C) and above (39 °C, 41 °C) the standard cultivation temperature (37 °C) on porcine muscle development. Therefore, we used our porcine primary muscle cell culture derived from satellite cells as an in vitro model. Neonatal piglets have limited thermoregulatory stability, and several days after birth are required to maintain their body temperature. To consider this developmental step, we used myoblasts originating from thermolabile (five days of age) and thermostable piglets (twenty days of age). Results The efficiency of myoblast proliferation using real-time monitoring via electrical impedance was comparable at all temperatures with no difference in the cell index, slope or doubling time. Both temperatures of 37 °C and 39 °C led to similar biochemical growth properties and cell viability. Only differences in the mRNA expression of myogenesis-associated genes were found at 39 °C compared to 37 °C with less MYF5, MYOD and MSTN and more MYH3 mRNA. Myoblasts grown at 35 °C are smaller, exhibit higher DNA synthesis and express higher amounts of the satellite cell marker PAX7, muscle growth inhibitor MSTN and metabolic coactivator PPARGC1A. Only permanent cultivation at 41 °C resulted in higher HSP expression at the mRNA and protein levels. Interactions between the temperature and donor age showed that MYOD, MYOG, MYH3 and SMPX mRNAs were temperature-dependently expressed in myoblasts of thermolabile but not thermostable piglets. Conclusions We conclude that 37 °C to 39 °C is the best physiological temperature range for adequate porcine myoblast development. Corresponding to the body temperatures of piglets, it is therefore possible to culture primary muscle cells at 39 °C. Only the highest temperature of 41 °C acts as a thermal stressor for myoblasts with increased HSP expression, but it also accelerates myogenic development. Cultivation at 35 °C, however, leads to less differentiated myoblasts with distinct thermogenetic activity. The adaptive behavior of derived primary muscle cells to different cultivation temperatures seems to be determined by the thermoregulatory stability of the donor piglets.


1993 ◽  
Vol 34 (4) ◽  
pp. 234-239 ◽  
Author(s):  
Richard J. Kavoussi ◽  
Emil F. Coccaro ◽  
Howard Klar ◽  
Juliet Lesser ◽  
Larry J. Siever

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