Ultrastructural correlation of water reabsorption in isolated rat cauda epididymidis

Summary Electron microscopic study was made on the water reabsorption of the epithelial cells of the rat cauda epididymidis. It was shown that when the epididymal duct was reabsorbing water at a maximal rate, widely dilated intercellular spaces were seen. It is suggested that the standing gradient model of water reabsorption first proposed for the gall bladder may also operate in the cauda epididymidis.This work was supported in part by the World Health Organization and grant number 158/254 of Hong Kong University.     

Ultrastructural correlation of water reabsorption in isolated rat cauda epididymidis

Electron microscopic study was made on the water reabsorption of the epithelial cells of the rat cauda epididymidis. It was shown that when the epididymal duct was reabsorbing water at a maximal rate, widely dilated intercellular spaces were seen. It is suggested that the standing gradient model of water reabsorption first proposed for the gall bladder may also operate in the cauda epididymidis.     

Cellularity and composition of epididymal adipose tissue from cold-acclimatized rats

Summary Cold acclimatization induces morphological and compositional modifications of rat epididymal adipose tissue: a decrease in fat cell size, an increase of fat cell number per g of tissue, but no significant increase in total fat cell number in the tissue; finally, an increase in protein content and a decrease in triglyceride content.Acknowledgments. We especially thank Mr M. Joliff for his very valuable help for fat cell size determination (Hospital Bichat, Paris).     

Cellularity and composition of epididymal adipose tissue from cold-acclimatized rats.

Cold acclimatization induces morphological and compositional modifications of rat epididymal adipose tissue: a decrease in fat cell size, an increase of fat cell number per g of tissue, but no significant increase in total fat cell number in the tissue; finally, an increase in protein content and a decrease in triglyceride content.     

A comparison of the effects of several diuretics and sulfhydryl reagents on the in vitro clotting time of rat,guinea-pig and human blood

Résumé On étudie l'effet d'une série de composés (capables de réagir avec les groupes sulfhydryle des protéines) sur la vitesse de coagulation du sang recalcifié du rat, du cobaye et de l'homme. Le chlorure méthylique de nercure accélère la coagulation chez le rat et le cobaye, mais la retarde chez l'homme. Le méralluride accélère et l'acide éthacrinique retarde la coagulation du sang chez certains sujets humains, mais n'ont aucun effet chez le rat et le cobaye. Le mérsalyle prolonge de beaucoup le temps de coagulation chez le rat, le cobaye et l'homme, mais le PCMB et le HgCl₂ n'ont pas d'effet.     

Age-dependent changes of rat liver plasma membrane composition

Summary The chemical composition of liver plasma membrane was studied in Wistar rats aged between 3 and 24 months. Results obtained indicate a significant age-dependent positive correlation of both the protein:phospholipid and cholesterol:phospholipid ratios, whereas the protein:cholesterol ratio seems to remain unaffected. Phospholipid analysis of liver plasma membrane reveals that only the phosphatidylcholine content has a significant negative correlation with age; all other phospholipid species remain basically unchanged.Supported by a grant of the Italian National Research Council, Project Preventive and Rehabilitative Medicine, Subproject Mechanisms of Aging.     

Age-dependent changes of rat liver plasma membrane composition

The chemical composition of liver plasma membrane was studied in Wistar rats aged between 3 and 24 months. Results obtained indicate a significant age-dependent positive correlation of both the protein: phospholipid and cholesterol: phospholipid ratios, whereas the protein: cholesterol ratio seems to remain unaffected. Phospholipid analysis of liver plasma membrane reveals that only the phosphatidylcholine content has a significant negative correlation with age; all other phospholipid species remain basically unchanged.     

A comparison of the variability of muscle,hair, lens and plasma proteins

Résumé Trois groupes de protéines structurelles (celles de la lentille, celle des muscles, et celles du poil) furent comparés aux protéines de plasma, en utilisant l'électrophorèse en gel polyacrylamide. Les variations apparaissant chez 4 espèces de rongeurs furent examinées et on trouva que les protéines de plasma varient plus que les autres. L'importance de ces résultats dans la recherche d'une évolution possible de ces protéines est considérée.

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It is a pleasure to thank ProfessorB. C. Clarke, Mrs.R. M. Clayton and Dr.D. E. S. Truman for valuable discussions. This work was carried out during the tenure of a Research Studentship from the Medical Research Council.     

A comparison of methods for the inactivation of third component of guinea-pig complement

Riassunto Sono stati esaminati comparativamente tre reagenti per la titolazione di C₃, rispettivamente allestiti con siero di cavia inattivato con zymosan, formalina e «Liquoid». Le differenze esistenti tra essi sono state analizzate e discusse in base alle attuali conoscenze sulla natura del terzo componente complementare.

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Supported in part by Contract DA-49-007-MD-696 with the Office of the Surgeon General, Department of the Army.     

Effect of fasting on the lipid composition and enzyme activity of rat liver plasma membranes

After 24-h fasting, when the recovery of plasma membrane protein isolated from rat liver was unchanged, the enrichment in 5'-nucleotidase was decreased by 16%. Modifications of the lipid composition were also observed and resulted in a 27% decrease of the cholesterol/phospholipid molar ratio.     

Effect of fasting on the lipid composition and enzyme activity of rat liver plasma membranes

Summary After 24-h fasting, when the recovery of plasma membrane protein isolated from rat liver was unchanged, the enrichment in 5-nucleotidase was decreased by 16%. Modifications of the lipid composition were also observed and resulted in a 27% decrease of the cholesterol/phospholipid molar ratio.     

Carboxypeptidase A,ionic strength,and the enhancement of guinea-pig complement

Zusammenfassung Potenzierung von Meerschweinchen-komplement durch niedrige Ionenkonzentration und Carboxypeptidase A zeigt, dass das Enzym seinen stärkeren Einfluss während der Bildung von EAC ausübt. Während der Immunhämolyse übte jedoch eine niedere Ionenkonzentration einen zusätzlichen fördernden Einfluss auf eine spätere Reaktion aus.     

Glycosaminoglycans in separated tubules of the guinea-pig and rat kidney medulla

Isolated tubules of the renal medulla of guinea-pig and rat contained glycosaminoglycans. 20--25% of the uronic acids corresponded to hyaluronic acid. In the guinea-pig, chondroitin and dermatan-sulfates accounted for at least 50% of the uronic acids, whereas, in the rat, heparan sulfates comprised 65--70% of them.     

Glycosaminoglycans in separated tubules of the guinea-pig and rat kidney medulla

Summary Isolated tubules of the renal medulla of guinea-pig and rat contained glycosaminoglycans. 20–25% of the uronic acids corresponded to hyaluronic acid. In the guinea-pig, chondroitin and dermatan-sulfates accounted for at least 50% of the uronic acids, whereas, in the rat, heparan sulfates comprised 65–70% of them.Supported, in part, by CONICET, Argentina, Mrs N. Ramonda-Becerra assisted in the electrophoretic assays.     

Size ofTrichinella spiralis (nematoda) muscle cysts in the rat,mouse and guinea-pig

Zusammenfassung Bei Ratte, Maus und Meerschweinchen ist die Grösse der Muskelzysten vonTrichinella spiralis 60 Tage nach standardisierter experimenteller Infektion bestimmt worden. Die Grösse der Muskelzysten variierte bei jeder der 3 untersuchten Tierarten erheblich. Bei der Ratte wurden durchschnittlich grössere Muskelzysten vonT. spiralis gefunden als bei der Maus, bei der die Muskelzysten wiederum durchschschnittlich grösser waren als beim Meerschweinchen. Die Zystengrösse vonT. spiralis scheint demnach vom Stoffwechsel der jeweils als Wirt dienenden Tierart abhängig zu sein.