Lactate transport in canine red blood cells

OBJECTIVE: To detect monocarboxylate transporters (MCTs) in canine RBC membranes and to determine the distribution of lactate between plasma and RBCs. SAMPLE POPULATION: Blood samples obtained from 6 purpose-bred Beagles. PROCEDURES: Monocarboxylate transporter isoforms 1, 2, 4, 6, 7, and 8 and CD147 were evaluated in canine RBCs by use of western blot analysis. Lactate influx into RBCs was measured as incorporation of radioactive lactate. RESULTS: 2 MCT isoforms, MCT1 and MCT7, were detected in canine RBC membranes on western blot analysis, whereas anti-MCT2, anti-MCT4, anti-MCT6, and anti-MCT8 antibodies resulted in no signal. No correlation was found between the amount of MCT1 or MCT7 and lactate transport activity, but the ancillary protein CD147 that is needed for the activity of MCT1 had a positive linear correlation with the rate of lactate influx. The apparent Michael is constant for the lactate influx in canine RBCs was 8.8 +/- 0.9mM. Results of in vitro incubation studies revealed that at lactate concentrations of 5 to 15mM, equilibrium of lactate was rapidly obtained between plasma and RBCs. CONCLUSIONS AND CLINICAL RELEVANCE: These results indicated that at least half of the lactate transport in canine RBCs occurs via MCT1, whereas MCT7 may be responsible for the rest, although an additional transporter was not ruled out. For practical purposes, the rapid equilibration of lactate between plasma and RBCs indicated that blood lactate concentrations may be estimated from plasma lactate concentrations.     

Frost hardiness of nutrient-loaded two-year-old <Emphasis Type="Italic">Picea abies</Emphasis> seedlings in autumn and at the end of freezer storage

The effects of nutrient loading (NLOAD) on the frost hardening and dehardening of Picea abies (L.) Karst. seedlings were investigated under nursery conditions. Before NLOAD, second-year container seedlings were either short-day (SD) treated for 3 weeks in July or left for the natural photoperiod (CO). By mid-September, after 5 weeks of NLOAD, the fertilization of three foliar nutrient concentration levels (low = L-SD, medium = M-SD, and high = H-SD) for the SD-treated seedlings and one (medium = M-CO) for the CO-seedlings was completed. The NLOAD resulted in foliar nitrogen concentration 10.6, 16.1, 22.3, and 17.5 g kg⁻¹ for L-SD, M-SD, H-SD and M-CO seedlings, respectively. The NLOAD had no effects on the morphology or dry mass variables of the seedlings, while SD-treatment reduced the dry mass of shoots, but not that of roots. The frost hardiness (FH) of different batches of the seedlings was assessed by the visual scoring of damage in their needles, stems and buds after their controlled exposure to freezing during frost hardening and dehardening. The low nutrient concentration in the SD-treated seedlings (L-SD seedlings) resulted in poor FH, to an even lower extent than that of the M-CO seedlings. The NLOAD did not affect the dehardening of the seedlings at the end of the freezer storage in the following spring.     

Price integration for domestic and imported sawlogs and pulpwood in Finland: an update

This paper provides an analysis on the integration of prices for imported coniferous pulpwood and sawlogs, and respective domestic stumpage prices in the Finnish wood market. Eight real price series were investigated during 2002–2014 using monthly observations. The bounds testing approach by Pesaran et al. [(2001) Bounds testing approaches to the analysis of level relationships. J Appl Econom. 16: 289–326. doi:10.1002/jae.616], indicates there are long-run relationships between prices of domestic and imported wood. For more detailed information, the vector error correction model (VECM) approach was used. Estimation of a system with all eight prices with interpretable results did not succeed; therefore, we estimated models for prices of sawlogs and for pulpwood separately. For sawlogs, two co-integrating vectors, one for pine and one for spruce, were found. For pulpwood prices, one co-integrating vector was identified. The estimated VECMs confirm the results of bounds testing approach, suggesting that causation in the Finnish wood market runs from domestic prices to prices of imported wood. We conclude that prices of domestic and imported coniferous logs and pulpwood are closely connected. The question of full integration remains open, as border prices and stumpage prices by definition differ, at least, by logging and transportation costs.