The effects of temperature on ATPase activity and force generation in skinned muscle fibers from the Pacific blue marlin (Makaira nigricans)

Summary ATPase activity and force generation have been measured simultaneously in isolated, demembranated muscle fibers of the Pacific blue marlin (Makaira nigricans) between 0 and 30°C. Tension generation is relatively independent of temperature above 15°C and falls with a Q₁₀ of <1.5 on decreasing the temperature to 0°C. In contrast, the Q₁₀ for ATPase activity is 2.2 over the range 0–30°C. The results are interpreted in terms of the cross bridge theory of contraction.     

Serotonin levels in fish brain: Effects of hydrostatic pressure and water temperature

Summary The contents of serotonin (5 HT) and its metabolite 5 hydroxy indoleacetic acid (5 HIAA) have been measured (HPLC technique) in the brains of eels exposed to different conditions of hydrostatic pressure and temperature (HP=1 or 101 ATA in winter, Tw=14°C, and in summer, Tw=19°C). It appears that an increase of Tw induces a significant increase of the 5 HT/5 HIAA ratio. In contrast, eels exposed at 101 ATA of HP for 1 h do not exhibit any modification in the 5 HT/5 HIAA brain ratio at a given temperature. The involvement of 5 HT under the conditions studied is discussed.     

Juvenile hormone and reproduction in the cricket. II. Effect of rearing temperature on corpus allatum activity (in vitro) in adult females

Summary In the Mediterranean field cricket,Gryllus bimaculatus, reproduction is controlled by temperature and the corpus allatum (CA) hormone JH III. In CA of females reared at 24°12°C(168 h) (high reproduction rate) a first peak in JH III synthesis is reached about 4 days earlier than in those of 20°C females (low reproduction rate). Furthermore, in 20°C animals CA activity is low during the entire oviposition period, whereas at 24°12°C high CA activity is found during this period of adult life. The results indicate a stimulation of CA activity and reproduction by thermoperiods around a constant low temperature.Supported by the DFG (SFB 87 A 4).     

The effect of head heating on the flight activity of the cockroach

Summary Internal head heating restricted the flight activity in the cockroachPeriplaneta americana. Heating the metathoracic ganglion did not have any pronounced effect on the flight. It is concluded that in the cockroach the head nervous centers are very heat-susceptible and might be the coordinating center for temperature responses.     

The influence of the sex-hormone testosterone on body temperature and metabolism of the male Japanese quail (Coturnix coturnix japonica)

Summary Testosterone causes a significant body temperature decrease in male quails. Oxygen consumption/g b.wt remains the same, however.     

The 5-Hydroxytryptamine content of the brain and some other organs of the hedgehog (Erinaceus europaeus) during activity and hibernation

Zusammenfassung Der 5-Hydroxytryptamingehalt des Igelhirns während der kalten Jahreszeit und besonders während des Winterschlafs war stets höher als mitten im Sommer. Die grösste Zunahme wurde in den Grosshirnhemisphären gefunden. Mechanismus und physiologische Bedeutung der Änderung wurde diskutiert und dabei angenommen, dass diese im Zusammenhang mit einer autonomen Regelung des Hibernationszustandes stehe.     

Cumulative record of motor activity. (A new procedure and its use for the study of central stimulant drugs)

Zusammenfassung Eine Methode zur kumulativen Registrierung spontaner motorischer Aktivität kleiner Tiere wird beschrieben. Die Wirksamkeitsbestimmung aus dem kumulativen Rekord und die analytische Bedeutung der Methode für die Wirkungsweise zentralstimulierender Substanzen wird diskutiert.     

Comparison of the time courses of luteinizing hormone (LH) secretion rates during continuous stimulation by LH-releasing hormone (LH-RH) in vivo and in vitro

Summary The patterns of LH secretion during constant stimulation of the pituitary glands of estradiol-treated ovariectomized rats with a maximally stimulating amount of LH-RH in vivo and in vitro correspond with each other qualitatively and quantitatively. In vitro the changes with time of the LH secretion rate are somewhat retarded, especially the occurrence of desensitization.     

Development and evaluation of a method of high pressure liquid chromatography for the determination of the level of degradation of thyroliberin (TRH) in blood]

The degradation of the TRH by plasma was studied using a sensitive method for the separation of TRH and products formed by high-pressure liquid chromatographic analysis (HPLC). The detected products are TRH-3H or synthetic TRH. The HPLC analysis is performed on a microparticulate (10 mu) silica gel chromatographic column with CH3CN/0,01 M NH4OAc, at pH 6 (30/70) (V/V). This technique provides a good separation of TRH and the other products of degradation. In our experimental conditions, the human plasma degrades 62.5 +/- 5% of of TRH in 60 mn; very similar results are obtained with thin layer chromatography.     

The effect of locality,breed and previous tick experience on seasonal changes in the resistance of cattle toBoophilus microplus (Ixodoidea: Ixodidae)

Summary A seasonal cycle in the expression of resistance to the tickBoophilus microplus occurs in cattle in central and southeastern Queensland, Australia. This is due to a seasonal fluctuation in the capacity of cattle to mount an effective immune response against the parasitic tick and is manifest as a waning of the expression of resistance in autumn and early winter which occurs irrespective of breed or the nutritional state of the cattle.     

Studies onHolothuria polii (Echinodermata) antibacterial proteins. I. Evidence for and activity of a coelomocyte lysozyme

Summary Lysozyme activity has been detected in coelomocyte lysate of the echinodermHolothuria polii. The bacteriolytic reaction was stable when the lysate was heated in acidic buffer but heat-labile in alkaline medium. An incubation temperature of 35°C, acidic pH values (5.2 and 6.2) and an ionic strength of 0.175 were found to be the best conditions for the coelomocyte enzymatic activity. A low level of lysozyme was also evidenced in cell-free coelomic fluid where it could represent a basal defense level of bacteriolytic molecules released by the coelomocytes.Acknowledgments. This work was supported in part by a grant from MRES (C. C.). The authors thank M. Lasségues and F. Lassalles for their help and criticism.     

Relevance of chlorine-substituent for the antifungal activity of syringomycin and syringotoxin,metabolites of the phytopathogenic bacteriumPseudomonas syringae pv.syringae

Structural analogues of syringomycin and syringotoxin were produced by fermentation, characterized by FAB-MS and amino acid analysis and compared to the parent compounds in the antibiosis test againstRhodotorula pilimanae. The C-terminal residue was shown to be important for the activity.     

Isoforms of soluble alpha-tubulin in oocytes and brain of the frog (genus Rana): changes during oocyte maturation

Rana oocytes have previously been shown to contain much more soluble tubulin than does the brain, suggesting different assembly and disassembly dynamics of frog oocyte tubulin compared to that in brain. By using centrifugation, SDS-PAGE, two-dimensional gel electrophoresis and Western blots, probed with anti-α-tubulin monoclonal antibodies, polymorphic α-tubulins (isoforms) were compared in brains and follicle-enclosed oocytes of northern (Rana pipiens) and southern (R. berlandieri) frogs. Oocyte tubulin in both species had isoforms with greater ranges of isoelectric point (pI) than those of brain tubulins; in particular, the oocyte tubulin pIs ranged further into the acidic region of the isoelectric-focusing gels than corresponding brain tubulin. This difference may, in part, be responsible for the previously reported assembly differences between oocyte tubulin (undetectable assembly) and brain tubulin (high assembly). Isoforms of α-tubulin with relat ively acidic pI were more abundant in northern frog brain and oocyte soluble extracts than in analogous extracts from southern frogs. Furthermore, additional acidic α-tubulin isoforms were found in progesterone-treated oocytes (i.e., eggs), indicating increased heterogeneity of acidic a-tubulin isoforms during oocyte meiotic maturation. Among northern frog oocyte soluble components fractionated on Superose-6b columns, tubulin complexes with apparent molecular mass of about 1800 kDa were found to contain acidic α-tubulin isoforms while the putative oligomeric tubulins with an apparent molecular mass of about 250 kDa contained an additional relatively basic α-tubulin isoform. The acidic α-tubulin isoforms, therefore, are proposed to be associated with cold-adaptable cells of brain and oocytes, and may also be involved in stabilization of large soluble tubulin complexes in oocytes of the northern frog. Received 1 October 2002; accepted 9 October 2002 RID="*" ID="*"Corresponding author.     

The viability of pollen grains of a lily (Lilium auratum) and the eggs of the brine-shrimp (Artemia salina) soaked in organic solvents for 10 years

Summary Pollen grains ofLilium auratum which had been stored in n-pentanol, n-butanol and n-propanol for 10 years at –10°C germinated, and the generative nucleus in the pollen tube divided into 2 sperm nuclei. The resting eggs ofArtemia salina soaked in these solvents for 10 years hatched at a high rate.     

The effect of epinephrine and the hyperglycemic factor of the scorpion's cephalothoracic ganglionic mass (CTGM) on the phosphorylase activity of hepatopancreas of the scorpion,Heterometrus fulvipes C. Koch

Summary Injection of epinephrine and CTGM extract showed different effects on hepatopancreatic phosphorylase activity and levels of total carbohydrate and glycogen in heterometrus fulvipes. The former hyperglycemic principle involves phosphorolysis of glycogen whereas the latter does not.The authors are grateful to Proff. K. S. Swami and S. Nagaiah. An award of Junior Research Fellowship by the Council of Scientific and Industrial Research, New Delhi is acknowledged by K. R.