Effects of Freund's complete adjuvant on the dirunal rhythms of neuroendocrine processes and ornithine decarboxylase activity in various tissues of male rats

The aim of this study was to investigate the effects of Freund's complete adjuvant (FCA) on the diurnal rhythms of hormonal parameters in serum and ornithine decarboxylase (ODC) activity in various tissues of male rats. On days 1–2 after FCA, increase of ODC activity (used to evaluate the level of activation) was observed in the hypothalamus, pituitary gland, adrenal medulla, adrenal cortex, liver and lymphoid tissues, while the ODC activity in the kidney was reduced. This was accompanied by an increase in serum corticosterone. On days 3–4 after FCA, ODC activity remained elevated in the pituitary gland, liver and lymphoid tissues, while the ODC activity in the testes and panceas was reduced; kidney ODC activity returned to baseline. This was associated with increased serum levels of prolactin (Prl) and luteinizing hormone, but decreased growth hormone, testosterone and insulin. The increase in ODC activity in the thymus, as well as the reduced ODC activity in the testes and kidney, can be obtained with paraffin. Furthermore, bromocryptine microcapsules (CBLA) reduced the FCA-induced increase of ODC activity in the pituitary gland, liver and lymphoid tissues (days 3–4) but did not affect the changes in other tissues. The increase in ODC activity in the pituitary gland, liver and lymphoid tissues is specific for FCA. A role for Prl in the induction of ODC in liver and lymphoid tissues is suggested by the fact that CBLA suppresses this enhancement.     

Specific immunosuppression of IgE response to hapten DNP by DNP linked to monoclonal IgG1 in rats

Summary The induction of the anti-DNP IgE in rat was suppressed by pretreatment of rats with the tolerogen synthesized by coupling DNP to rat IgG, i.e.; DNP_7–10-IgG. It was found that DNP₁₀-IgG₁ was an effective tolerogen, whereas other DNP conjugates, i.e. DNP₉-IgM, DNP₉-IgA, DNP₁₀-IgE, DNP₁₀-IgG_2c and DNP₁₀-IgG_2a were ineffective.This work was partly supported by a research grant from the Medical Council of Canada to W.Y.L.     

Induction of chromosomal aberrations by the anthracycline antitumor antibiotics N,N-dimethyldaunomycin and aclacinomycin A

The clastogenic effect of the anthracycline antitumor antibiotics, N,N-dimethyldaunomycin and aclarcinomycin A, was studied in a murine hemopoietic cell line (Friend leukemia cells). A dose-dependent increase in chromatid lesions, i.e., achromatic lesions, chromatid breaks, chromatid deletions and triradial or quandriradial chromosomal exchange fiqures, was found. It appears that the clastogenicity of N,N-dimethyldaunomycin and aclacinomycin A is lower than that of the classic anthracycline, daunomycin, which is also a potent mutagen and carcinogen. The data demonstrate that the capacity of chemicals to induce point mutations and chromosomal aberrations may not necessarily be correlated: aclacinomycin A is devoid of mutagenic activity in bacterial (Salmonella typh.) and mammalian cell (HGPRT) mutagenesis assays, and is non-carcinogenic in rats. Nevertheless, it was now found to possess clastogenic activity.     

Induction of chromosomal aberrations by the anthracycline antitumor antibiotics N,N-dimethyldaunomycin and aclacinomycin A

Summary The clastogenic effect of the anthracycline antitumor antibiotics, N,N-dimethyldaunomycin and aclacinomycin A, was studied in a murine hemopoietic cell line (Friend leukemia cells). A dose-dependent increase in chromatid lesions, i.e., achromatic lesions, chromatid breaks, chromatid deletions and triradial or quadriradial chromosomal exchange figures, was found. It appears that the clastogenicity of N,N-dimethyldaunomycin and aclacinomycin A is lower than that of the classic anthracycline, daunomycin, which is also a potent mutagen and carcinogen. The data demonstrate that the capacity of chemicals to induce point mutations and chromosomal aberrations may not necessarily be correlated: aclacinomycin A is devoid of mutagenic activity in bacterial (Salmonella typh.) and mammalian cell (HGPRT) mutagenesis assays, and is non-carcinogenic in rats. Nevertheless, it was now found to possess clastogenic activity.     

Induction in rabbits of reverse-type,immediate skin reaction by specific anti-rabbit IgG and anti-rabbit IgA

Résumé Un sérum spécifique de chèvre anti-IgG de lapin ou un sérum de cobaye anti-IgA de collostrum de lapin inoculés dans le derme de lapins normaux provoquent chez ces derniers une réaction d'hypersensibilité immédiate. Par contre, le sérum spécifique de chèvre anti-IgM de lapin ne provoque pas de réaction. Les mêmes résultats ont été observés chez tous les lapins testés.     

Effects of disodium EDTA on the cardiovascular responses to prostaglandin E1

Zusammenfassung Die Wirkung des Dinatrium-EDTA auf die Kreislaufreaktionen des Prostaglandin E₁ (PGE₁) wurde an narkotisierten Hunden untersucht. Das Ausmass der positiv chronotropen und inotropen Einflüsse des PGE₁ war während der Infusion von EDTA bedeutend geringer als das des PGE₁ vor der EDTA-Gabe. Die Gegenwart oder das Einströmen von Kalziumionen scheint in der pharmakologischen Wirkung des PGE₁ eine Rolle zu spielen.     

Pathways of sugar metabolism in relation to the biosynthesis of polyacetylenic antibiotics

Zusammenfassung Der Einbau von [1-¹⁴C]-Acetat bei der Biosynthese von Xylose aus Äthanol durch die Basidiomycete B-841 beweist das Vorhandensein von drei verschiedenen Wegen des Zuckerstoffwechsels in diesem Pilz: 1. Glycolyse, 2. Transaldolase-Transketolase-Zyklus, 3. Abbau von Glucose zu Glucuronat und Pentose.     

Adrenal responses to hypoxia and hypercapnia in the young calf

Summary Quantitative analysis of adrenal responses to moderate hypoxia and hypercapnia in the conscious calf shows that the sensitivity of the adrenal cortical response far exceeds that of the adrenal medulla.Acknowledgment. This work has been supported by grants from the Agricultural Research Council, the Medical Research Council and the Wellcome Trust. We are also indebted to Dr D. M. Burley (CIBA) for his continued support.     

Baroreceptor and sympathetic responses to acebutolol, a beta 1-adrenoceptor-blocking agent, in rabbits.

Baroreceptor activity was increased after i.v. infusion of acebutolol in rabbits with an intact circulation, and in rabbits with a total cardiopulmonary by-pass. In rabbits with an intact circulation, renal nerve activity was reduced.     

Modification of the contractile responses of rabbit mammary strips to oxytocin by prostaglandin E1.

PGE1 administration to isolated strips from pregnant and lactating rabbit mammary gland resulted in different effects on oxytocin-induced contractions. In strips from pregnant animals, oxytocin action was enhanced; in those from lactating animals, it was reduced and threshold doses for oxytocin were markedly higher.     

Transfer and induction of delayed hypersensitivity to methylated bovine serum albumin in the absence of adjuvant]

Delayed hypersensitivity to methylated bovine serum albumin may be induced in Mice without adjuvant, by injecting the antigen either with sensitized T lymphocytes, or by injecting just the antigen in Mice preptreated with Cyclophosphamid.     

Pharmacogenetic factor in the convulsive responses of mice to flurothyl

Résumé La sensibilité convulsive a été determinée dans 6 groupes de souris par les réactions de l'ether hexafluorodiéthyle, convulsivant chimique. La lignée DBA/2 fut très sensible, tandis que les lignées C57BL/6 et BALB/c se montrèrent les moins sensibles. La sensibilité convulsive ne présenta pas de corrélation positive avec l'activité locomotrice.