Adipokines as biomarkers of postpartum subclinical endometritis in dairy cows

Adipokines emerged as regulators of metabolism and inflammation in several scenarios. This study evaluated the relationship between adipokines (adiponectin, chemerin and visfatin) and cytological (subclinical) endometritis, by comparing healthy (without), transient (recovered by 45 days postpartum (DPP)) and persistent (until 45 DPP) endometritis cows (n = 49). Cows with persistent endometritis had higher adiponectin concentrations in plasma (at 21 DPP, P < 0.05 and at 45 DPP, P < 0.01) and in uterine fluid (at 45 DPP, P < 0.001), and higher chemerin concentrations in plasma (P < 0.05) and uterine fluid (P < 0.01) at 45 DPP than healthy cows. Cows with persistent endometritis had higher gene transcription in the cellular pellet of uterine fluid and protein expression in the endometrium of these adipokines and their receptors than healthy cows. Adiponectin plasma concentrations allowed to discriminate healthy from persistent endometritis cows, in 87% (21 DPP) and 98% (45 DPP) of cases, and adiponectin and chemerin uterine fluid concentrations at 45 DPP allowed for this discrimination in 100% of cases. Cows with concentrations above the cutoff were a minimum of 3.5 (plasma 21 DPP), 20.4 (plasma 45 DPP), and 33.3 (uterine fluid 45 DPP) times more at risk of evidencing persistent endometritis at 45 DPP than cows with concentrations below the cutoff. Overall, results indicate a relationship between adipokine signalling and the inflammatory status of the postpartum uterus of dairy cows, evidencing that adipokines represent suitable biomarkers of subclinical endometritis, able to predict the risk of persistence of inflammation.

D-glucose transport and concentration in tumoral insulin-producing cells

The uptake of D-[U-14C]glucose and D-[5-3H]glucose by tumoral insulin-producing cells of the RINm5F line was measured over 3-30 min of incubation at 7-37 degrees C. The apparent distribution space of the hexose ranged from values as low as the L-[1-14C]glucose space to values 10 times higher than the 3H2O space. Although a major fraction of the radioactivity recovered in the cellular pellet corresponded to the metabolites of D-glucose, the results suggested that the transport of D-glucose into the tumoral cells represents a saturable and temperature-dependent process. When D-glucose was measured by an enzymic procedure in cells incubated for 30 min at 37 degrees C in the presence of 50.0 mM D-glucose, the apparent distribution space of the hexose remained lower than the intracellular water space. These results indicate that the RINm5F cells have lost an essential attribute of the glucose-sensing device in normal insulin-producing cells, namely the ability to ensure the equilibration of D-glucose concentrations across the plasma membrane.