Chlorodimeform and its effect on monoamine oxidase activity in the cattle tick, Boophilus microplus.

The action of the acaricide, chlorodimeform and its metabolite. N-desmethylchlorodimeform, on the activity monoamine oxidase (MAO) from the cattle tick, Boophilus microplus, were studied. Both compounds were found to be potent in vitro and in vivo inhibitors of the enzyme. However the inhibition of MAO does not seem to be related to the toxic action of the acaricide.     

Norepinephrine as principal catecholamine in a specific neurone of an invertebrate (Boophilus microplus: Acarina)

Summary Norepinephrine has been identified as the principal catecholamine in individual neurons of the synganglion of an arthropod, the cattle tickBoophilus microplus. This suggests that norepinephrine may have a hitherto unsuspected major physiological role in at least one group of invertebrates.     

The relationship of phosphodiesterase and cyclic AMP to the process of fluid secretion in the salivary glands of the ixodid tick Amblyomma americanum.

Phosphodiesterase (PDE) activity in the salivary glands of the female. Amblyomma americanum decreased as the tick progressed from a slow to a rapid phase of feeding, while the rate of fluid secretion increased when glands were stimulated with cyclic AMP and theophylline. Dopamine stimulated PDE activity and an 'inhibitory' factor was found in glands obtained from rapidly engorging ticks which decreased PDE activity. These findings are discussed as they relate to the process of fluid secretion by salivary glands of feeding ixodid ticks.     

Effect of botulinum toxin on the choline acetyltransferase activity in salivary glands of cats

Summary The choline acetyltransferase activity of submandibular glands that had previously received a retrograde injection of botulinum toxin via their ducts was found to be markedly lower than in the untreated contralateral glands. In the parotid glands exposed to the same treatment the activity of this enzyme was less affected.This work was supported by grants from the Wellcome Foundation to S. K. K. and J. R. G., and from the Faculty of Medicine in Lund to J. E.     

Peroxidase activity and thiocyanate accumulation in salivary glands

Summary Salivary glands with high, low, or no peroxidase activity do not differ in [S¹⁴CN^–] after the i.v. injection of KS¹⁴CN, nor do the glands differ from blood and muscle in [S¹⁴CN^–]. The content of SCN^– in a salivary gland does not mirror the gland's participation in the peroxidase-mediated antimicrobial mechanism.     

Adrenergic nerves in the major salivary glands of the rabbit

Zusammenfassung Es ist bekannt, dass die Ausbreitung der adrenergischen Speicheldrüsennerven der Ratte in enger Verbindung mit der Sekretion bei sympathischer Reizung steht. Die Submaxillaris- und Parotisdrüsen des Kaninchens waren reichlich mit adrenergischen Nerven versorgt. Die sympathische Sekretion der Submaxillarisdrüse war indessen sehr gering, während die der Parotisdrüse beträchtlich war. Die Versuche deuten darauf hin, dass die sympathischen Nerven nicht nur eine sekretorische Funktion haben.

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J. R. Garrett on leave from the Department of Oral Pathology, Kings College Hospital, London S.E. 5, wishes to acnowledge a travel grant made by theEley-Webster Trust.     

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.     

On theβ-adrenergic receptors in salivary glands of rat and dogs

Zusammenfassung Nachweis an Ratten und Hunden, dass Salbutamol, ähnlich wie Noradrenalin, nur in höherer Dosierung, die Speichelsekretion der Submaxillaris, nicht aber die der Parotis erhöhen kann. Diese Wirkung kann durch Propanolol aufgehoben werden, was zeigt, dass sich in der Submaxillaris offenbar ₁-Rezeptoren befinden.     

Octopamine,dopamine and noradrenaline content of the brain of the locust,Schistocerca gregaria

Summary The octopamine, dopamine and noradrenaline content of the brain of the locust,Schistocerca gregaria has been determined using sensitive radiochemical-enzymatic assays. Octopamine and dopamine are present in high concentration but the noradrenaline content is only 1/25 that of octopamine. Both reserpine and fusaric acid (a dopamine--hydroxylase inhibitor) produce a significant depletion of the octopamine stores.The author is a M.R.C. of Canada Fellow. Thanks are due to Drs.A. A. Boulton, A. V. Juorio, andP. H. Wu for helpful discussion.     

Effect of acetylcholine,dopamine, noradrenaline and 5-hydroxytryptamine on the incorporation of32P into phospholipids of the snail brain

Zusammenfassung Von den im Schneckenhirn (Helix pomatia) wahrscheinlich als Neurotransmitter wirkenden Substanzen führen Dopamin und Acetylcholin zu einem erhöhten Einbau von³²P in Phospholipide; Serotonin zeigt eher einen gegenteiligen Effekt und Noradrenalin bleibt ohne Einfluss. Phosphatidylinositol weist die höchste Einbaurate auf. Die Resultate unterstreichen die Bedeutung von Dopamin, Acetylcholin und Serotonin als Neurotransmitter im Schneckenhirn und deren Einfluss auf den Metabolismus von Membranphospholipiden.     

Rate of depletion of noradrenaline in some peripheral tissues induced by a reserpine injection

Zusammenfassung Nor-Adrenalin (NA) verschwindet nach einer Reserpininjektion im Uterus des Kaninchens langsamer als in anderen Organen: nach 12 h noch Nachweis von Aminen in den vasomotorischen Uterusnerven, nicht aber zum Beispiel in derGl. submandibularis. Tendenz zu gleicher Reaktion zeigt der Uterus des Meerschweinchens, nicht aber der Ratte, der Maus oder des Hamsters. Es wird der Schluss gezogen, dass verschiedene sympathische Nervenendigungen gleicher Aufgabe variierende Grundeigenschaften zeigen.

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This study was aided by grant NB 02854-04 from the United States Public Health Service.     

Structure and pharmacological actions of eledoisin,the active endecapeptide of the posterior salivary glands of eledone

Riassunto Viene descritto il procedimento che ha permesso l'isolamento ed il chiarimento della struttura chimica dell'eledoisina, l'endecapeptide attivo delle ghiandole salivari posteriori dell'Eledone. L'eledoisina è dotata di potente azione ipotensiva, particolarmente spiccata nel cane, e di intensa azione stimolante su alcuni preparati di muscoli lisci extravasali. L'eledoisina è facilmente distinguibile, mediante saggi paralleli, da tutti gli altri polipeptidi biogeni finora descritti.

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Supported in part by a grant from the Rockefeller Foundation, New York.