Publikationsdatenbank

Insulin and magnesium increase the activity of GPDH in bovine adipocytes (2019)

Art

Poster

Autoren

Jurek, Sandra (WE 2)

Sadhu, Mansur A. (WE 2)

Trappe, Susanne (WE 2)

Kolisek, Martin

Sponder, Gerhard (WE 2)

Aschenbach, Jörg R. (WE 2)

Kongress

International Symposium on Ruminant Physiology (ISRP 2019)

Leipzig, 03. – 06.09.2019

Quelle

Advances in Animal Biosciences

Bandzählung: 10

Heftzählung: 3

Seiten: 430

ISSN: 2040-4719

Sprache

Englisch

Verweise

URL (Volltext): https://www.cambridge.org/core/services/aop-cambridge-core/content/view/7D464B8882B4D5304683797665CD9E5E/S2040470019000037a.pdf/proceedings_of_the_xiiith_international_symposium_on_ruminant_physiology_isrp_2019.pdf

Kontakt

Institut für Veterinär-Physiologie

Oertzenweg 19 b
14163 Berlin
+49 30 838 62600
physiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Purpose:
Lipomobilization at the onset of lactation is linked to insulin deficiency and/or insulin resistance. Magnesium is known to increase sensitivity to insulin and could thus potentially alleviate lipomobilization. The aim of the present study was to measure the activity of glycerol-3-phosphate dehydrogenase (GPDH) in bovine adipocytes at different concentrations of magnesium and insulin to investigate the potential role of magnesium for insulin sensitivity. GPDH is an adipogenic differentiation marker that catalyzes the reaction of dihydroxyacetonphosphate and NADH to glycerol-3-phosphate and NAD+.

Material and methods:
Bovine subcutaneous adipose tissue was collected from five young calves. Preadipocytes were cultivated as an explant culture. After 48 h, preadipocyte differentiation was induced and differentiating cells were subsequently incubated with various concentrations of magnesium (0.1 mM, 0.3 mM, 1 mM, and 3 mM) and insulin (25 pM, 250 pM, and 25 nM) in a two-factorial design for 7 days. GPDH activity was measured in 1 x 106cells by a colorimetric GPDH activity assay kit. One unit of GPDH represents an enzyme activity required to generate 1.0 μmole of NADH per minute. Results are given as percentage relative to preadipocyte GPDH activity (GPDH%).Statistics were conducted by two-way repeated measures ANOVA.

Results:
Following incubation over 7 days, GPDH% was affected by both insulin (P = 0.045) and magnesium concentration (P = 0.037). The effect of insulin was based on a trend towards lowest GPDH% at intermediate insulin concentration (125 ±13 % at 250 pM), especially when compared to the lowest insulin concentration (188 ±17 % at 25 pM; P = 0.054). A concentration of 3 mM magnesium induced a trend for higher GPDH% (214 ±21 %) compared to all other magnesium concentrations (138 ±15 % at 0.1, 135 ±15 % at 0.3 mM and 136 ±15 % at 1 mM; P < 0.062 each).

Conclusion:
Insulin affects GPDH activity of cultivated bovine adipocytes. Surprisingly, however, a trend for lowest activity was observed at concentrations that would reflect high insulin levels in vivo (250 pM). A high magnesium concentration of 3 mM increased GPDH activity independently of insulin. The latter may point to the fact that the magnesium effect on GPDH activity may not necessarily be a direct consequence of increased insulin sensitivity.