Comparative evaluation of the depth of collagen and hyaluronic acid hydrolysis <Emphasis Type="Italic">in vitro</Emphasis> by collagenase and hyaluronidase preparations

The molecular weights of collagen and hyaluronic acid solutions after their incubation with collagenase and hyaluronidase were evaluated by capillary viscosimetry. The results indicate high amylolytic activity of collagenase and the absence of proteolytic activity in hyaluronidase in an in vitro system. Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 146, No. 7, pp. 89–90, July, 2008     

Rosanol: electrophysiologic and biophysical study]

It has been established that rosanol, obtained from bulgarian rose oil, averts fatal disturbances of the cardiac rhythm induced by calcium dichloride and also prevents the onset of severe changes on the electrocardiogram provoked by a high-frequency electric stimulation of the mesencephalic reticular formation and by an intravenous administration of high doses of norepinepharine. In experiments on mitochondria the authors make an attempt to explain this antiarhythmic effect of rosanol by stabilization of the membranous potential.     

Locomotor effects of nitrous oxide in mice: requirement of newly-synthesized and main intraneuronal storage pools of dopamine

Abstract— Nitrous oxide increases locomotor activity in mice. Other locomotor stimulants are thought to act via central dopaminergic mechanisms and can be divided into two groups as determined by their antagonism by tyrosine hydroxylase inhibitors or by reserpine pretreatment. The purpose of the present study was to determine if nitrous oxide fits one or the other of the groups. Mice were acclimatized for 1 h to exposure chambers (4 L filtration flasks), in air, delivered at 4 L min^?1 and then exposed to N₂O:O₂ (50:50), also delivered at 4 L min^?1. Locomotor activity was evaluated at 10 min intervals throughout the experiment. Racemic α-methyltyrosine methyl ester HCl (200 mg kg^?1), administered at the beginning of acclimatization, almost totally eliminated the nitrous oxide effect but not that of methylphenidate HCl (20 mg kg^?1). Reserpine pretreatment (5 mg kg^?1 18 h) totally eliminated the nitrous oxide effect but not that of amphetamine (5 mg kg^?1). The results suggest that nitrous oxide requires both the newly synthesized and the main storage pools of dopamine and do not allow assignment of the agent, specifically, to either of the groups.     

Endothelial cell culture on fibrillar collagen: model to study platelet adhesion and liposome targeting to intercellular collagen matrix.

Human umbilical endothelial cells (ECs) were grown on fibrillar type I collagen in 16.4-mm multiwell tissue culture plates. Human platelets were added to the wells, and platelet adhesion to collagen was examined by scanning electron microscopy and radioisotopic technique in the absence of ECs and in preconfluent and confluent EC cultures. Single adherent platelets of different shapes as well as small aggregates were seen on collagen surface. Human plasma fibronectin added to the system stimulated platelet adhesion and their spreading on collagen. ECs had no effect on the percentage of platelets adherent to collagen-coated gaps in preconfluent culture but decreased the number of spread platelets. It is demonstrated that collagen-coated gaps can bind 14C-labeled liposome--antibody and 14-C-labeled liposome--fibronectin conjugates. ECs grown on fibrillar collagen are suggested as useful models for screening of antiplatelet drugs and for the study of drug targeting to the areas of vascular injury for prevention of thrombosis.