Importance of the anti-serotonin effect for mounting behaviour in rats

Zusammenfassung «Mounting behaviour» bei Ratten wird nicht nur durch die Kombination Testosteron plus Parachlorphenylalanin hervorgerufen. Auch durch die Gabe von Testosteron in Kombination mit den Substanzen Mesorgydin, WA 335-BS und Methysergid, die unter anderem antiserotonergen Effekt haben, wird «mounting behaviour» bei männlichen Ratten ausgelöst. Aufgrund dieser Ergebnisse und zitierten Beobachtungen ist eine ursächliche Bedeutung zwischen dem Anti-Serotonin-Effekt und der Aktivierung des «mounting behaviour» bei männlichen Ratten anzunehmen. Die spezifische Wirkung der Substanz PCPA allein kann für dieses Verhalten nicht verantwortlich gemacht werden.     

Biochemical efficiency and intrinsic shortening speed in selected vertebrate fast and slow muscles

Summary The biochemical efficiency was measured in iodoacetate N₂ and NaCN-treated muscles by dividing the work done by the amount of phosphoryl creatine hydrolysed when contracting at their optimum velocity. An inverse relationship was found between the intrinsic speed of shortening (V_max) of the muscles and their mechanochemical efficiency.     

Extracellular but not intracellular application of peptide hormones activates pancreatic acinar cells.

Peptide hormones, like neurotransmitters, are traditionally thought to activate cells by interacting with receptor sites accessible only from the extracellular space. However, there is no available evidence that establishes whether intracellular injections of peptide secretagogues can or cannot initiate cell activation. In view of recent demonstration that peptide hormones can penetrate the intracellular space in some tissues and the reports that intracellular injections of the neurotransmitter, dopamine, into acinar cells of cockroach salivary gland cause stimulation it seems of fundamental importance to test directly whether introduction of peptide secretagogues inside acinar cells of mammalian exocrine tissue can induce cell activation without first interacting with the outer surface of the external cell membrane. The data presented here show that injections of the secretagogue peptides caerulein and bombesinnonapeptide (bombesin-NP) into pancreatic acinar cells fail to evoke the characteristic potential and conductance changes that are observed following extracellular applications of these peptides.     

Effects of testosterone-stimulated glycogen synthesis in the mouse salivary glands and 5-fluorouracyl inhibition

Resumen En el presente trabajo se estudia la accion de testosterona sobre el metabolismo del glucogeno. Se observa que despues de la inyeccion de la hormona aumenta el glucogeno y que y este es inhibido por 5-FU. Se sugiere que la sintesis de glucogeno necesite una estimulacion previa de nucleotidos de RNA y de proteinas.

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This work was supported by a grant from the Consejo Nacional de Investigaciones Cientifica y Tecnica, Argentina.     

The effect of lidocaine on the secretion induced by cholera toxin in the cat small intestine

Summary The intraluminal administration of lidocaine, a local anaesthetic agent, inhibits the net loss of fluid into the intestinal lumen produced by cholera toxin in the cat. It is suggested that the activation of a nervous reflex is involved in the pathogenesis of cholera.This research was sponsored by grants from the Swedish Medical Research Council (14X-2855), from the Swedish Society for Medical Sciences, from Magnus Bergvalls Stiftelse and from the Medical Faculty, University of Göteborg.     

Isolierte gaumenspalte und chondrocranium

Summary In the chondrocranium of mice with induced cleft palates, the ethmoid region is not affected by this malformation. The paramedian cartilagenous structures of the orbito-temporal region of 17-day-old and new-born mice, however, show a distinct reduction in dorso-ventral height. These deformities prove that the cleft palate malformation is not topographically restricted to the palate. It is assumed that both the cleft palate and accompanying alterations are due to to defective induction in the prechordal area of the embryonic head.