There is limited knowledge about how the interaction of dissolved organic carbon (DOC) and inorganic nitrogen (N) released into the soil just after freezing can affect methane (CH4) uptake in forest soils. Here, we present how freezing treatment and glucose, as a DOC source, can affect the roles of NH4(+)-N and NO3(-)-N in inhibiting soil CH4 uptake, by using soil-core incubation experiments. A...

Metabolic acidosis has profound effects on vascular tone. This study investigated the in vivo effects of acute metabolic acidosis (AMA) and chronic metabolic acidosis (CMA) on hemodynamic parameters and endothelial function. CMA was induced by ad libitum intake of 1% NH4Cl for 7 days, and AMA was induced by a 3-h infusion of 6 M NH4Cl (1 mL/kg, diluted 1:10). Phenylephrine (Phe) and acetylcholi...

We determined that ribosomes of seedling roots of maize (Zea mays L.) contain the acidic phosphoproteins (P-proteins) known to form a flexible lateral stalk structure of the 60S subunit of eukaryotic ribosomes. The P-protein stalk, composed of P0, P1, and P2, interacts with elongation factors, mRNA, and tRNA during translation. Acidic proteins of 13 to 15.5 kD were released as a complex from ri...

The influence of ammonia and inhibition of the urea cycle by norvaline on orotic acid synthesis in five Polish Merino ewes was investigated. The sheep were exposed to 60 min of successive infusions of 0.9% NaCl, NH4Cl (20 mumol kg-1 min-1), and NH4Cl with DL-norvaline (10 mumol kg-1 min-1) solutions administered to the mesenteric vein. The average rate of orotic acid output, urea output and amm...

We report here the synthesis and properties of a hybrid toxin prepared by covalently coupling diphtheria toxin to transferrin. The purified material contained two major hybrid protein species and was highly cytotoxic to mouse LMTK- cells in culture, reducing protein synthesis by 50% in 24 h at a concentration of 1 ng/ml. Cytotoxic activity was completely abolished in the presence of exogenous t...

We compared the effect of hyperammonemia on NADH levels in brain slices, and on the rate of oxygen consumption from isolated non-synaptic brain mitochondria, in ammoniasensitive Wistar rats with that in ammonia-tolerant gulf toadfish (Opsanus beta). The NADH content was significantly decreased (12% less than control after 45 min with 1 mM NH4Cl) in rat brain slices, but it was not affected in b...

An uncoupler-sensitive active transport of sulphate into membrane vesicles prepared from the plasma membrane of Paracoccus denitrificans (previously Micrococcus denitrificans) can be driven by respiration or by a trans-membrane pH gradient (alkaline inside) generated by the addition either of KCL ( in the presence of nigericin) or of NH4CL. Valinomycin does not substitute for nigericin. Respira...

Light chain exchange in 4.7 M NH4Cl was used to hybridize the essential light chain of cardiac myosin with the heavy chain of fast muscle myosin subfragment 1, S-1. The actin-activated ATPase properties of this hybrid were compared to those of the two fast S-1 isoenzymes, S-1(A1), fast muscle subfragment 1 which contains only the alkali-1 light chain, and S-1(A2), fast muscle myosin subfragment...

The metabolism of [1-14C] glutamate to 14CO2 and the glutamate dehydrogenase (GLDH) activity towards alpha-ketoglutarate (alpha-KG) formation were measured in bulk isolated astrocytes derived from control rats and rats with acute hepatic encephalopathy (HE) induced with thioacetamide. In addition, the effects of in vitro treatment of control and HE astrocytes and non-synaptic mitochondria with ...

• Stimulation of potassium (K) efflux by sodium (Na) has been the subject of much recent attention, and its mechanism has been attributed to the activities of specific classes of ion channels. • The short-lived radiotracer K was used to test this attribution, via unidirectional K-flux analysis at the root plasma membrane of intact barley (Hordeum vulgare), in response to NaCl, KCl, NH4Cl and ma...