The effect of early weaning on spermiogenesis in adult rats

Zusammenfassung Junge, vorzeitig (18 Tage nach der Geburt entwöhnte Ratten) zeigen im Alter von 12 Monaten Schädigungen im spermiogenen Hodenepithel. 12 Tage später entwöhnte Ratten entwickeln sich normal. Die beobachteten Schädigungen treten im Alter von 6 Monaten noch nicht auf.     

A study of the mechanism of lowering the sensitivity of smooth muscle to noradrenalin with sympathetic hyperinnervation

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The mechanism of blood vessel permeability derangement under the influence of histamine,serotonin and bradykinin

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Relationship of ornithine decarboxylase activity to HCG induced androgen production by rabbit testis

Summary In the rabbit testicular ornithine decarboxylase activity and androgen content as well as serum androgens were increased 4 h after the injection of HCG. D,L-a-difluoromethylornithine (a-DFMO) alone or together with HCG inhibited enzyme activity although testicular and serum androgens were significantly increased aftera-DFMO and HCG. These data suggest that ODC activity is not required for testicular androgen production.This work was supported by the Medical Research Council of Canada, MT 4192.     

A putative role for eosinophils in tick rejection

Summary In the reaction ofBos taurus cattle to infestation by the tickBoophilus microplus, mast cell histamine is translocated by the eosinophils to the attachment site. The concentration pattern of this cutaneous mediator for pain appears related to the grooming behaviour of the host.     

In situ accumulation of marine algal exudate by a polychaete worm (Schizobranchia insignis)

Summary For the first time, heterotrophic accumulation of dissolved carbon by a soft-bodied marine invertebrate under in situ conditions has been demonstrated. The polychaete wormSchizobranchia insignis Bush concentrated¹⁴C-labelled dissolved carbon (DC) exudated by the large brown alga,Macrocystis integrifolia Bory, 14 times over the killed controls. Our evidence suggests that algal exudate may be a significant nutritional supplement to some invertebrates cohabitating withM. integrifolia.This study was supported by Operating Grant No. A6966 to PVF from the National Research Council of Canada.We are grateful to MrG. F. Cota, Dalhousie University, Halifax, for his contributions to the field experiments.