Releasing of plasminogen-activator from the kidney to the blood (author's transl)]

When fibrinolytic activity in blood samples from various vessels was examined by the dilute-blood-clotlysis-time method (DBCLT), it was found to be noticeably high in the renal venous blood, though the activity was not detected by usual blood clotlysis time method. Plasmin was not detected in any blood samples examined, and the contents of fibrinogen and fibrin (or fibrinogen) breakdown products in the renal venous blood were not significantly different from those in the blood from other vessels. However, the high activity of plasminogen-activator was found only in the renal venous blood. Inhibitors on plasmin and plasminogen-activator (urokinase) were detected in almost the same amount in the blood samples from the various vessels. The amount of the inhibitors was sufficient to inhibit the plasminogen activation by urokinase, whose activity was equivalent to the plasminogen-activator activity in the renal venous blood. These results indicate that the high activity by DBCLT in the renal venous blood was derived from the high activity of plasminogen-activator, which was inactivated by inhibitors in undiluted blood. Plasminogen-activator may be released from the kidney to the blood, and immediately inactivated by the inhibitors in renal vein, and then diluted with systemic blood which contains little plasminogen-activator.     

Vertical movement of dolphinfish <Emphasis Type="Italic">Coryphaena hippurus</Emphasis> as recorded by acceleration data-loggers in the northern East China Sea

Environmental changes influence foraging behavior for most animals. Dolphinfish, Coryphaena hippurus, are epipelagic predators and have a cosmopolitan tropical to warm-temperate (>20°C) distribution. We simultaneously obtained the ambient temperature and the foraging behavior (i.e., swimming speed, depth and tailbeat acceleration) of dolphinfish, using an acceleration data-logger in May, September, October, November 2007, June 2008, May and July 2010 for 8 individuals. Although the dolphinfish spent a mean ± standard deviation of 43.4 ± 27.7% of their time at the surface (0–5 m), dive excursions from the surface (DES) were observed in all individuals and maximum DES depths ranged from 50.1 to 95.4 m. DES events resulted dives below the thermocline for these dolphinfish, and there was a significantly positive relationship between the isothermal layer depth (ILD) and DES depth. Our results demonstrate that dolphinfish avoided the rapid thermal change beyond the thermocline, and their prey is most likely found in the upper layers of the thermocline. Gliding behavior during the DES phase was also observed and dolphinfish gradually descended to deeper waters with gliding. The gliding time was longer when the ILD was deeper, and fish tended to dive deeper. We suggest that dolphinfish adopt gliding behavior to search a broader range of depths for prey, while minimizing energy use.     

Effects of opioid peptides on thyrotropin-releasing hormone release from the rat caecum in vitro

Effects of opioid peptides (beta-endorphin, dynorphin (1-13). alpha-neoendorphin, beta-neoendorphin, leucine-enkephalin, methionine-enkephalin) on the release of thyrotropin-releasing hormone (TRH) from the rat caecum were studied in vitro. The rat caecum was incubated in medium 199 with 1.0 mg/ml of bacitracin (pH 7.4) (medium). The amount of TRH release from the rat caecum into the medium was measured by radioimmunoassay. The immunoreactive TRH (ir-TRH) release from the rat caecum was inhibited significantly in a dose-related manner with the addition of opioid peptides. The inhibitory effects of opioid peptides on ir-TRH release from the rat caecum were blocked with an addition of naloxone. The elution profile of acid-methanol-extracts of rat caecum on Sephadex G-10 was identical to that of synthetic TRH. The findings suggest that opioid peptides inhibit TRH release from the rat caecum in vitro.     

RADIOAUTOGRAPHIC STUDY OF TRANSLOCATION IN BEAN LEAVES

The movement of the radioactivity from sucrose, indole-3-acetic acid (IAA) and phosphate has been examined in excised bean leaves. Preferential translocation of the labelled materials toward the base of leaf and petiole was demonstrated, suggesting a natural mobilization gradient down the leaf and petiole. Establishment of other mobilization centers in the leaf by local application of N⁶-benzyladenine diverted the movement of the sucrose label and, to a lesser extent, the phosphate label. There was no apparent mobilization of IAA by benzyladenine. Evidence is provided that there is a continuity of label from the source to the sink regions, and it is suggested that reported instances of noncontinuity of label may be attributable to the refixation of respired C¹⁴O₂ by tissue treated with benzyladenine. The observations appear to substantiate the concept that the unloading of solutes from the phloem can regulate the direction and intensity of translocation.     

Enantioselectivity-promoting factor in enzyme-mediated asymmetric hydrolysis of enol esters

Enantioselectivity-promoting factor enhances enantioselectivity of protonation in lipase AP-catalyzed asymmetric hydrolysis of enol esters. The factor was partially purified by chromatography using Phenyl-TOYOPEARL 650M and Sephacryl S-200HR. The hydrolysis of 2-benzyl-l-cyclohexenyl acetate by PLE in the presence of the purified factor produced (R)-2-benzylcyclo-hexanone in 92% ee, while the reaction without the factor gave the racemate.     

Genetic study on the mandibular molar size of rats

Tooth size is determined by genetic and environmental factors like other quantitative characters such as body weight and body height. However, the degree of the relative contribution of both factors to the determination of tooth size has not been well clarified. In order to study the genetic and environmental factors affecting tooth size, we carried out a diallel cross mating by the cohabitation of pairs of males and females among 10 strains of rats. The bucco-lingual widths of the first, second, and third molars of the right mandible were measured in each offspring of F1 population. The body weight was also measured as a parameter that might indicate systemic growth factor in connection with tooth development. The quantitative genetic analysis was performed based on Wearden's model (Heredity 19:669-680, 1964). As a result, the size of the first and the second molars was more significantly controlled by genetic effect than maternal effect, while maternal effect could not be ignored for the size of the third molar in addition to genetic effect. The genetic effect on body weight became greater with age, while the maternal effect showed its maximum influence upon the body weight around the weaning. It is concluded that the size of the molar teeth beginning to develop in the uterus and to be calcified just after birth was mainly controlled by genetic factor, and that the size of the molar teeth beginning to develop approximately after birth was mainly controlled by maternal effect affecting body weight at the same period.