Cytogenetic differences in radiation effects on red-haired field mice from different geographic populations]

The paper presents the data on the effect of X-rays on the incidence of chromosome aberrations and on the mitotic activity of bone marrow cells in two geographical populations of Clethrionomys glareolus. It is shown that the percentage of aberrant cells at different intervals after the irradiation (350 r) is higher in the Moscow population than in the Komi ASSR population. The fractionation radiation results in different increase in the number of aberrant cells. The change of the mitotic activity after X-irradiation was also different in these two geographical populations.     

Gender Differences in Subjective Time Evaluation and Sensitivity to Antianxiety Drugs

Differences in subjective time evaluation were found between young women and men. The women displayed a shorter individual minute (IM), which decreased in the evening as compared to the morning. The antianxiety drugs valerian and Grandaxin increased the IM at different times of the day irrespective of the gender of the subjects, which coincided with their antianxiety effect.     

Interaction of aliphatid alcohols with cytochrome P-450 from rat liver microsomes]

The interaction of alyphatic alcohols and cyclohexanol with cytochrome P-450 in microsomes has been investigated. All alchohols induced the modified 11 type spectral changes by mixing with microsomes. These changes are characterized by lambdamax = 412 and lambdamin = 380-382 nm in difference spectra. The dissociation constants of the alcohol cytochrome P-450 complexes are determined. On this dissociation constants influence pH and Triton X-100 presence. The interaction of the alcohols with cytochrome P-450 in phosphate buffer pH = 6,0 in the detergents absence is characterized by one dissociation constant for MeOH, EtOH, n-BuOH and cyclohexanol and by two dissociation constants for i-PrOH, i-BuOH and tert.-BuOH. The interaction of the alcohols with cytochrome P-450 in Tris-HCL-buffer (pH 7.5) in the Triton X-100 presence is characterized for all above alcohols by the dissociations constants, which are described by Taft equation with coefficient rho =-1.55. This fact confirms the interaction of alcohols HO-groups with heme iron of cytochrome P-450. The scheme of interaction of alcohols with cytochrome P-450 is discussed.     

Picrotoxin effects on frog ERG at different background illumination but same stimulus contrast

The effect of blockade of GABAergic synapses by picrotoxin on the b- and d-wave of frog ERG was investigated under scotopic (0.002 lx), mesopic (2 lx) and photopic (200 lx) background illumination (Ib). Diffuse white stimuli with two levels of contrast (0.5 and 2.5) were used with each Ib. The aim was to compare the effects of picrotoxin at different background levels, but same stimulus contrast. We found that picrotoxin markedly increased the amplitude and rate of rise of the leading edge of the b- and d-wave with each Ib. This effect was most pronounced at mesopic Ib, smaller at photopic Ib and least pronounced at scotopic Ib. It was relatively stronger on the d-wave than on the b-wave amplitude under scotopic and mesopic conditions. Under photopic conditions, the difference between the picrotoxin effect on the b- and d-wave was much smaller. The possible neuronal mechanisms of the above described picrotoxin effects are discussed.