[Optical and scanning electron microscopic study of the structural development of the cecum and colon walls in the rabbit (Oryctolagus cuniculus L.) during the perinatal period]. / Etude en microscopie optique et electronique a balayage de l'evolution structurale des parois du caecum et du colon, durant la periode perinatale, chez le lapin (Oryctolagus cuniculus L.).

The study, through optical and scanning microscopy, of various developmental stages, from the 24th day of gestation to the 13th day after birth, shows a quick development of the structures of the caecal and colic mucosal layers to the adult forms, from the very first week of postnatal life. The distal part of the colon is full-grown before the other parts of the alimentary canal, and is particularly rich in mucous cells. The caecum is the place where an early lymphoid defense is provided, from the 30th day of gestation.

[Changes in functional and metabolic characteristics of isolated rat heart during initial phase and long lasting perfusion]. / Evolution des caractéristiques fonctionnelles et métaboliques du coeur isolé de rat durant la phase initiale de la perfusion et au cours de perfusions de longues durées.

Mechanical performance, tissue content of high-energy phosphates (ATP and CP), glycogen and phosphorylase activity were measured in isolated rat hearts either just after excision (hearts arrested by plunging in ice-cold perfusate) or during long time perfusions (6 h) at 37 degrees C. Arrested hearts exhibited : (1) higher total phosphorylase activity (a + b); (2) higher percentage of phosphorylase a; (3) lower CP content. During perfusion, high energy phosphates appeared well maintained whereas glycogen content and phosphorylase activity decreased with a significant correlation between these two parameters. The validity of this isolated heart model and possible implications of the variations in phosphorylase activity are discussed.