Showing papers in "Eksperimentalna meditsina i morfologiia in 1990"

A modification of the toxic effects of platinum complexes with antocyans

Abstract: The toxic and antitumor properties of biocysplantinum (cis-diaminodichlo-platinum) as well as a new platinum complex with acetic acid after their single and combined usage with antocyanes were studied on healthy mice and mice with transplanted ascitic tumour of Ehrlich There was a reduction in total toxicity of biocysplatinum after simultaneous administration with antocyanes (300 mg/kg per os) Protective effect of antocyanes was observed on leukocytopoiesis Preservation of antitumor activity of platinum complexes was found in the tumour of Ehrlich The obtained data indicate possibilities for usage of antocyanes as chemioprotectors during therapy with drugs, containing platinum

The effect of dopaminergic pharmacological agents on the pancreatic islet apparatus in rats

Abstract: Experimental studies were carried out on white male sexual mature healthy rats with induced alloxan diabetes, to clarify the role of dopaminergic system in the regulation of functions of the insular apparatus of the pancreas. The experiments were performed by the following drugs: bromrcripine, levodopa, a combination of revodopa plus carbidopa and haloperidol. Parameters of carbohydrate metabolism were determined in the course of acute and chronic experiments. The results sustained the hypothesis for participation of dopaminergic system in the regulation of production and secretion of insulin and respectively in the control of carbohydrate metabolism. Independent studies were carried out on white rats with alloxan diabetes after combined administration of dopaminergic pharmacological drugs and sulphanylureic preparation (SUP)-glybenclimide. The mechanisms of interaction after the combined administration of the investigated drugs under the conditions of experimental diabetes mellitus were clarified. The obtained results supplement data, in support of the hypothesis for the role of dopamine as a neuromediator in the regulation of the insular apparatus of the pancreas.

The effects on the learning process of 4 pyrrolidine derivatives and of cyticholine (experiments on rats in a water maze)

Abstract: The experiments were carried out on 104 male white rats and the effects of pyracetamat, aniracetamat and 2 newly synthesized pirolidine derivatives P-CL, P-p as well as of cytidin-diphosphat choline (cyticholine) were examined on training in a water maze. All investigated substances were administered immediately after morning training orally in a dose of 100 mg/kg for a period of 5 days. Ten trainings were undertaken each day twice. Two parameters were determined: time of stay of the rat in the water maze (in seconds) and the number of mistakes (entrance of blind canals). Pyracetamat and cyticholine improved training of rats while the other examined substances showed insignificant effect. A conclusion is made that chemically close nootropic drugs could be differentiated substantially in respect to spatial memory as well.

The composition and structure of isolectins from Arum maculatum

Abstract: The delipidized saline extract of Arum maculatum (AM) contains two selectively agglutinating human spermatozoa isolectinesphytospermoagglutinins (FSA1 and FSA2), which bind to various receptors of spermatozoon plasmalemma. It is established by means of disc polyacrilamide electrophoresis amino acid analysis and isoelectric focusing that FSA1 is tetrameter, but FSA2-octameter, which have similar amino-acid content and do not contain carbohydrates. The established structural differences probably cause also the capability of FSA1 and FSA2 to bind various receptors of spermatozoon plasmalemma. It is proven that FSA2 possesses antigenic properties.

Female sex hormones and thrombocytopoiesis

Abstract: The influence of estradiol, estriol and progesterone was studied on basic parameters of thrombocytopoiesis and thrombocytopoietic activity of plasmas of female rats. It was established that the investigated hormones increased highly the number of thrombocytes, the percentage of 75-selenomethionine incorporated in newly formed thrombocytes and the total number of megakaryocytes. Thrombocytopoietic activity of the plasma was raised considerably only in rats, injected with estradiol, but the remaining hormones did not induce significant changes in this activity. It is accepted that estradiol, estriol and progesterone stimulate thrombocytopoiesis of female rats by various mechanisms. Estradiol increases highly the formation of specific humoral regulator of thrombocytopoiesis--throbocytopoietin. The stimulating effect of estriol and progesterone is most probably nonspecific (thrombocytopoietin-independent), as the first hormone activates proliferation of megakaryocytes greatly, but the second hormone-the differentiation of these cells.

[The effect of thyroid- and parathyroidectomy on stress-induced changes in the primary humoral immune response of white rats].

Abstract: The influence of the immobilization stress (24 h) was studied on male white rats of Wistar strain, examining the primary humoral immune response on the background of thyroid- and parathyroidectomy. It was established that parathyroidectomy induced immunodepression, but the effect of immobilization stress, used just next to immunization with sheep erythrocytes intensified immunodepression. Furthermore application of stress after immunization with sheep erythrocytes (during the effective phase of the immune response) induced immunostimulation. These differences in stress-induced immunological changes could be explained by the peculiarities of neuroendocrine and immunological status during the variants of stress action.

Eosinophilic granulocytes in the mouse thymus

Abstract: The morphological peculiarities and distribution of thymus eosinophils of 69 conventional Swiss mice in different stages of their prenatal and postnatal development have been investigated. Single granulocytes, located mainly in the cortical zone between the epithelial cells and lymphocytes have been observed. The early appearance of these cells (in 17-18 days old fetuses) and the simultaneous presence of mature eosinophils as well as of their precursors have been discussed with regard to the possibility for the mouse thymus to participate in the eosinophilopoiesis.

[Changes in the actin distribution in the neurons of the cerebral cortex in newborn, adult and old rats].

Abstract: The distribution of actin in neurons of sensorimotor cortex of newborn, 3-month- and 12-old-month old rats was studied by an immunohistochemical method. There was a diffuse staining of perikarya [correction of perikaryocytes] in contrast to the mature 3-month-old rats in which immunopositive material was located mainly at the periphery of neuronal bodies. A diffuse immunostaining was established in some nerve cells of the elderly 12-month-old rats.

[Changes in the articular and growth cartilage of young rats after the intra-articular injection of hydrocortisone].

Abstract: Changes in the cells and matrix of the joint cartilage (JC) and growing cartilage (GC) of tibias of young rats after five-fold administration of hydrocortisone in a dose of 10 mg/kg of body weight were studied by routine histological and histochemical methods. Fissures occurred in JC, but its superficial layer thickened. The cells of this layer acquired the form of fibroblasts, but the reaction for proteoglycans gradually weakened and became negative. The cells in the proliferative and hypertrophic zones were involved mainly in GC. The amount of granulated endoplasmic reticulum diminished. The number of myelin-like figures was increased. Pilings of thick collagenous fibers occurred in the matrix.

A neuropharmacological study of isoteolin (IST)

Abstract: Neuropharmacological study of IST was carried out on mice and rats, using the so-called practically "blind" neuropharmacological screening of M. Nikolova and L. Daleva (1968). The investigated product IST was administered under the form of 0.1-1% of solutions prepared ex tempore with saline in doses, equivalent to 1/440-1/250 to 1/2-4 1/2-4/5 of LD50. The studies on behaviour profile of mice and rats showed that IST induced symptoms of increasing inhibition of the central nervous system (CNS) in conformity with an increase in the dosage. It was established that IST inhibited dose-dependent spontaneous and stimulated with amphetamine motor activity and orientation reaction of mice, antagonized group amphetamine toxicity and excitatory effects of amphetamine as well as of morphine on mice; potentiated hexobarbital narcosis of mice and rats; lowered body temperature of rats; elevated the threshold of pentetrazolic seizures. In very high doses (50, 100 and 200 mg/kg i.p.), equivalent to 1/5 to 2/3 of LD50 IST induced excitatory effects on central and peripheral nervous system-provoked unaddressed aggressiveness, salivation, increased frequent breathing and chromodacryorrhea [correction of chromodacriurea]. The obtained experimental results show that IST manifest central depressive effect and has mainly neuroleptic character in respect to CNS.

The effect of adrenocorticotropic hormone (ACTH) and cycloheximide (CHM) on lipid biosynthesis in the rat lung

Abstract: The influence of ACTH, CHM and of ACTH + CHM was studied on lipid metabolism of lungs of rats by usage of a radioactive precursor 14C-acetate. It was established that the biosynthesis of total lipids, of triacylglycerols as well as of free fatty acids was increased under the influence of ACTH and CHM as this effect was mostly manifested after combined action of ACTH and CHM. The investigated factors manifested inhibiting effect on the synthesis of free cholesterol and total phospholipids. ACTH stimulated incorporation of 14C-acetate in the glycerol part of triacylglycerols as well as of the total phospholipids, while CHM and the combination of CHM and ACTH had inhibiting effect on the biosynthesis of the glycerol part of triacylglycerols and of total phospholipids.

[Acute-phase changes in ceruloplasmin after gamma-ray irradiation]

Abstract: The change of ceruloplasmin level of blood serum of guinea-pigs was studied on the 12th h after irradiation with gamma-rays from 60Co, using doses of 1-10 Gy, power of the dose of 0.68 Gy/min. The enzyme level was raised by the increase of the irradiation dose as it was reduced by the dose of 10 Gy in comparison with the control animals. This was probably due to inactivation of the molecules of ceruloplasmin by radicals and peroxides, obtained by this hyperlethal dose. Sera proteins showed a change in the increase of the dose: a reduction of albumins and an increase in beta- and gamma-globulins. Alpha-2-globulins, with which ceruloplasmin moved electrophoretically at low doses, showed slowly a slow increase in comparison with the control value, but at high doses-phase globulins. Oxidase activity of ceruloplasmin was determined by 01 todianisidine, but sera proteins-by agarose electrophoresis. The level of s ceruloplasmin in animals, irradiated by LD50 = 4.1 Gy, showed chronological change-an increase at early periods, maximum on the 12th h and a reduction at late periods close to the normal range. The level of serum copper followed the change in the enzyme level by analogy.