The reaction of the mast cell population to the intratracheal administration of heparin and fucoidan]

Mast cell population of rat after single intratracheal injection of heparin and fukoidan was investigated with cytofluorometry and cytochemical methods. These polysaccharides have great differences in the molecular weight nevertheless they both were found to include in mast cells.     

Characteristics of pharmacokinetics of liposome-incorporated rifampicin in rats after intratracheal administration]

Pharmacokinetics of rifampicin after its single intratracheal administration in the form of the liposome-encapsulated drug and its aqueous solution was studied on rats. It was shown that after the exposure to the liposome-incorporated rifampicin (10 mg/kg) the concentration-time curve in the blood and lungs was sigmoid with the retarded decrease in the blood drug concentration within 9 hours. The plateau segment of the curve provided at least a 4-fold longer maintenance of the rifampicin concentration in the blood and lungs at 3 to 4 micrograms/ml. The use of the liposome-incorporated antibiotic induced 2- and 1.5-fold increases in the AUC in regard to the lungs and blood, respectively.     

Mechanism of the antiexudative action of heparin]

The skin inflammation was induced by xylol application in experiments on rats. Exogenous and endogenous hyperheparinemia was found not to influence the dynamics of microcirculatory changes in the inflammatory area at the onset of its development, vascular permeability being significantly decreased. It is suggested that decreased vascular permeability plays an important role in the mechanism of antiexudative heparin action.     

Activity of adrenal cytoplasmic dehydrogenase following prolonged ACTH administration]

The activity of cytoplasmic dehydrogenases of the adrenal cells was examined during the prolonged injections of ACTH to Wistar rats. The indices of specific steroid synthesis function of the glands remained relatively high in the course of the whole experiment. Changes in the rats of corticosterone synthesis and dehydrogenase activities were phasic in character; they included an initial synchronic activation the first two days with its subsequent decrease (7 days of ACTH injections). The prevalence of activities of NADP-dependent dehydrogenases in combination with reactivation of steroidogenesis was marked during the concluding phase (13 days) of the experiment. A possibility of the adaptive role of selective activation of NADP-dependent enzymes in the maintenance of a high level of hormone biosynthesis under conditions of prolonged ACTH stimulation is discussed.     

Psychostimulation of Wistar rats after intraperitoneal administration of high-molecular heparin

The influence of repeated administration of heparin in learning was studied in Wistar rats (n = 20). High-molecular heparin (Serva, Germany, 10 kDa, activity of 180 IU/mg) was intraperitoneally injected daily in the dose of 64 IU/kg in a volume of 0.3 ml during 5 days prior to 4-link freechoice operant conditioning in a complex maze. As distinct from 40% of control rats, practically all heparin-treated rats were successful in conditioning. Parameters such as rate and efficiency of learning, behavior organization, habit stability, and extinction of errors were significantly better than in control animals. Anxiety was decreased, but sensitivity to external factors was increased in comparison with the control rats. The data obtained suggest that prior treatment with high-molecular heparin has a strong psychostimulant effect through activation of biogenic amines and formation of complexes with them.