Pathomorphological reactions and noradrenalin content of the heart after administration of depot angiotensin in trained and untrained rats

A 14-days' training of rats designed to adapt the animals to the procedure of blood-pressure measurement caused in the myocardium a decrease, in serum an increase in noradrenaline ( NA) content. The latter remained unchanged following 3 days of treatment with 2.5 mg depot angiotensin II (AII) but decreased by more than one-half in the myocardium of untreated animals, and increased in serum. Despite the considerable difference in myocardial NA content and blood-pressure behaviour, both trained and untrained rats showed the same morphological reactions following administration of A II. These myocardial alterations which largely correspond to the so-called epinephrine myocarditis should not therefore be due solely to NA action; rather, the involvement of A II should be considered also.     

Functional expression of the calcium release channel from skeletal muscle ryanodine receptor cDNA

Combined patch-clamp and fura-2 measurements were performed to study the calcium release properties of Chinese hamster ovary (CHO) cells transfected with the rabbit skeletal muscle ryanodine receptor cDNA carried by an expression vector. Both caffeine (1-50 mM) and ryanodine (100 microM) induced release of calcium from intracellular stores of transformed CHO cells but not from control (non-transfected) CHO cells. The calcium responses to caffeine and ryanodine closely resembled those commonly observed in skeletal muscle. Repetitive applications of caffeine produced characteristic all-or-none rises in intracellular calcium. Inositol 1,4,5-trisphosphate (IP3) neither activated the ryanodine receptor channel nor interfered with the caffeine-elicited calcium release. These results indicate that functional calcium release channels are formed by expression of the ryanodine receptor cDNA.     

Formation of septa in the bulbus cordis of a turtle and a lizard

The epithelium lining the intrahepatic bile ducts of normal adult mice consists of a single layer of cuboidal or low columnar cells and has ultrastructure comparable to that described previously (Rouiller and Jézéquel, '65). Some of the epithelial cells, however, exhibit such particular features as dilatation of granular endoplasmic reticulum cisternae, polysome formation of ribosomes and the presence of active forms of the Golgi apparatus, numerous lysosome-like bodies and apical projections and blebs. Postnatal cholecystectomy does not induce any qualitative changes in the epithelial fine structure, but results in a significant increase in number of the particular structures mentioned. Therefore, the cholecystectomy is thought to stimulate the secretory activity of the epithelial cells, and such stimulation appears due to the absence of a possible activity of epithelial secretion in the gallbladder.