Effects of duration of gonadectomy,sex and age on adrenal steroid 5α-reductase activity in the rat

Summary Within 6–8 weeks, gonadectomy in male and female rats leads to an increase in adrenal 5-steroid reductase activity. However, long-term post-orchiectomy enzyme activity decreases to the control level and this effect is not related to the age of animals.Supported in part by grant No.564/VI from Polish Academy of Sciences. Generous gift of hormones applied in these studies from The Upjohn Company, Kalamazoo, Michigan, USA is acknowledged.     

Effects of PGE2 and PGF2α on the simulation by noradrenaline and oxytocin of human cervical muscle activity at term

Summary Cervical specimens were obtained by needle biopsy in connection with caesarean section at term pregnancy. The preparations were superfused in an organ chamber and contractions were registered isometrically. Prostaglandin (PG) E₂ and F₂ inhibited spontaneous contractions. The stimulatory action of noradrenaline was not influenced by PGF₂ but was reduced by PGE₂ whereas both PGs abolished the excitatory effect of oxytocin.     

The effect of cyclic cytidine 3′,5′-monophosphate (cCMP) on the in vitro development,hatching and attachment of the mouse blastocyst

Summary The in vitro development and attachment of hatched mouse blastocysts on the untreated substratum was enhanced by 10 M dibutyryl cCMP (dbcCMP). The result suggests that cCMP has an effect on embryonic development and on the blastocyst attachment process.25 November1986     

Fever produced in rabbits by N6, O2′-dibutyryl adenosine 3′, 5′-cyclic monophosphate

Zusammenfassung Die Injektion von N⁶-2-O-Dibutyryl-adenosin-3 5-monophosphat in den lateralen Hirnventrikel von Kaninchen führt zu einer langanhaltenden Fieberreaktion, was vermuten lässt, dass zyklisches Adenosin-35-monophosphat als weiterer Mediator in der Genese des Fiebers fungiert.     

Effects of injury on the concentration ofα 1 andα 2 in the plasmas of male and female rats

Summary The effects of injury on the concentration of ₁-macroglobulin and ₂-macroglobulin in the plasmas of male and female rats has been investigated. At 5 days after injury to the male rats the ₁-macroglobulin concentration increased to 131% of its preinjury value. The ₂-macroglobulin concentration increased more rapidly to a maximum of 86 times its initial value. In the female rats ₂-macroglobulin increased only slightly and ₁-macroglobulin not at all.     

β-Methyl carboline,a benzodiazepine inverse agonist,attenuates the effect of triazolam on the circadian rhythm of locomotor activity

Summary The benzodiazepine triazolam, the benzodiazepine inverse agonist, -methyl carboline (-CCM) or both, were administered to adult male hamsters under conditions of constant light. When given alone, triazolam induced phase advances in the circadian activity rhythm of about 90 min, while -CCM when given alone, had no effect on phase of the activity rhythm. However, when triazolam and -CCM were given at the same time, the magnitude of the phase advances induced by triazolam were attenuated to about 30 min. These data, in conjunction with previous results, provide pharmacological evidence for a GABAergic system involved in the regulation of a central circadian pacemaker.     

The effect of o,p′-DDD on the adrenal cortex in sheep

Summary The effect of o,p-DDD (200 mg/kg/day given p.o. for 100 consecutive days) on the sheep adrenal gland was studied. The results suggest that this ruminant species is highly resistant to the adrenocorticolytic activity of o,p-DDD when compared with dogs.This work was supported by a grant of Bristol Laboratories, Syracuse, New York 13201, USA.     

Influence of sex,developmental time and food onβ-N-acetylglucosaminidase activity in the rice weevilSitophilus oryzae L.

Summary The effects of some biological parameters on -N-acetylglucosaminidase activity have been investigated inS. oryzae. There is no significant influence of sex and developmental time on the enzyme activity level, which appears in contrast to be greatly influenced by food (wheat or sorghum). Sorghum contains competitive inhibitors which are almost completely removed after dialysis. Fasting relieves this inhibition very quickly, suggesting that inhibitors act directly at the gut level.     

Effects of physalaemin, a vaso-active peptide from amphibian skin, on the excitability of an identifiable molluscan giant neurone of Achatina fulica Férussac.

We examined effects of several vasoactive peptides (substance P, physalaemin, neurotensin, bradykinin, angiotensin etc.) on the excitability of molluscan giant neurones identified in the subesophageal ganglia of Achatina fulica Férussac. Of these peptides, only physalaemin showed a remarkable excitatory effect on a giant tonically autoactive neurone.     

A human homolog of the yeast gene encoding tRNA 2′-phosphotransferase: cloning,characterization and complementation analysis

The Saccharomyces cerevisiae TPT1 gene plays a role in removing the 2-phosphate from ligated tRNA during the maturation of pre-tRNA. Here we reported the cloning and characterization of the human TRPT1 gene as a homolog of yeast TPT1. The TRPT1 gene is located at human chromosome 11q13 and encodes a polypeptide of 253 amino acids. BLAST searches with its amino acid sequence revealed the ubiquitous occurrence of TRPT1 homologs and their functional relationships with the presence of the DUF60/KptA domain. Northern analysis demonstrated that the gene is primarily expressed in heart and skeletal muscle, with lower or undetectable levels in other tissues studied. A plasmid-shuffling experiment showed that the human TRPT1 gene could complement the tpt1 mutation in S. cerevisiaeReceived 19 March 2003; received after revision 25 April 2003; accepted 22 May 2003     

Effects of ibotenic acid,quisqualic acid and their relatives on the excitability of an identifiable giant neurone of an African giant snail (Achatina fulica Férussac)

Summary An identifiable giant neurone, PON (periodically oscillating neurone), of Achatina fulica Férussac, inhibited by erythro--hydroxy-L-glutamic acid, was also inhibited by 2 relatives of -hydroxy glutamic acid, ibotenic acid and quisqualic acid. These substances similarly showed the effect on the neurone even in the chloride-free medium.The authors wish to thank Professor Emeritus T. Takemoto of Tohoku University, Dr H. Iwasaki of Takeda Chemical Co. and Professor C. H. Eugster of Zurich University for the donation of precious substances, and Miss H. Tamura for technical assistance.     

Effects of 2-β-D-glucosyl-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one onSchizaphis graminum (rondani) (insecta,aphididae) feeding on artificial diets

Summary 2--Glucosyl-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA-Glc), the main hydroxamic acid from maize and wheat, and its aglucone, decreased survival ofSchizaphis graminum reared on artificial diets. Both compounds were toxic for aphids and acted as feeding deterrents, at concentrations as low as 1 mM. The natural concentrations of glucosides of hydroxamic acids in wheat leaves reach up to 6 mmoles/kg fresh weight, thus falling within the range in which DIMBOA-Glc causes delecterious effects to diet-fed aphids.To whom correspondence should be addressed. THis work was supported by grants from International Foundation for Science (484), Universidad de Chile (N-1654) and the Agency for International Development.