Comparative analysis of the susceptibility and productivity of respiratory tract target cells of mice and rats exposed to inflienza virus in vitro

The levels of susceptibility to influenza virus A/Aichi/2/68 H3N2 and the virus yield were determined using primary cells of the trachea and lungs of CD-1 mice and Wistar rats, and for 3 sets of cells obtained from primary lung cells of the both species by centrifugation in the gradient of density and by sedimentation on a surface. The values of ID50 virus dose for 10(6) cells and virus yield per 1 infected cell determined for primary mice cells were 4.0+/-0.47 and 3.2+/-0.27 IgEID50 (lung cells), 3.8+/-0.17 and 3.3+/-0.20 IgEID50 (tracheal cells), and those determined for primary rat cells were 4.0+/-0.35 and 2.1+/-0.24 IgEID50 (lung cells), 3.7+/-0.27 and 2.2+/-0.46 IgEID50 (tracheal cells). The values of ID50 and yield measured for mixtures of cells obtained from primary lung cells by centrifugation in gradient of density and by sedimentation on a surface differed insignificantly (p = 0.05) from the values of the corresponding parameters measured for lung and tracheal cells for both rats and mice. The analysis of data on the variation of the concentrations of different cell types in the experimental cell mixtures shows that type 1 and 2 alveolocytes possess significantly lower (p = 0.05) susceptibility and productivity vs. ciliated cells of the both species. The investigation was conducted within the frame of the ISTC/DARPA#450p project.     

Lithium stimulation of granulopoiesis in diffusion chambers--a model of a humoral, indirect stimulation of stem cell proliferation

Lithium has been recognized as a stimulator of granulopoiesis both in vivo and in vitro. The mechanism by which lithium provokes this stimulation is unclear, with previous data focusing on such divergent causes as direct effects on progenitor cells v elevations in granulocyte macrophage colony-stimulating activity (GM-CSA) production. In the present study, we used a model system of granulopoiesis in diffusion chambers to study this stimulation of granulopoiesis. Lithium pretreatment of mice followed by a rest period to allow for excretion of the lithium (confirmed by serum assays) revealed a stimulation of progenitor cell growth within the diffusion chambers. No changes in the serum and chamber fluid GM-CSA levels were discernible between the control host mice and the lithium-pretreated mice. These data indicate that lithium stimulates granulopoiesis by an indirect mechanism that does not appear to involve GM-CSA.     

Age-related alterations in brain α1-adrenoceptors of hypertensive rats: Their possible role in the development of arterial hypertensionof hypertensive rats: Their possible role in the development of arterial hypertension

The binding of labeled agonist (³H-prazosin) to α₁-receptors in the frontal cortex, hypothalamus, and medulla oblongata of hypertensive (NISAG) and normotensive (Wistar) rats of different age is studied to elucidate the role of these receptors in the development of hereditary stress-induced arterial hypertension. It is found that the density of α₁-adrenoceptors in the hypothalamus of 30-day-old and adult NISAG rats is decreased, while in the medulla oblongata the number of these receptors, starting from the first week of life, is greater than in Wistar rats of the same age. From a comparison of these findings with the development of hypertension in NISAG rats it is concluded that α₁-adrenoceptors of the medulla oblongata are involved in this process. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 78–80, July, 1995 Presented by V. P. Kaznacheev, Member of the Russian Academy of Medical Sciences