Zhurnal evoliutsionnoi biokhimii i fiziologii最新文献

The stimulating effect of norepinephrine, isoproterenol and selective β-adrenoceptor (β3-AR) agonists BRL 37344 and CL 316.243 on the adenylyl cyclase signaling system (ACSS) in the brain and myocardium of young and mature rats (disease induction at 2 and 4 months, respectively) with experimental obesity and type 2 diabetes mellitus (DM2), and the influence of long-term treatment of animals with intranasal insulin (I-I) were studied. The AC stimulatory effects of β-agonist isoproterenol in animals with obesity and DM2 was shown to be practically unchanged. The respective effects of norepinephrine on the AC activity were attenuated in the brain of young and mature rats and in the myocardium if mature rats, and the I-I treatment led to their partial recovery. In the brain and myocardium of mature rats with obesity and DM2, the enhancement of the AC stimulatory effects of β3-AR agonists was observed, white in young rats the influence of the same pathological conditions was lacking. The I-I treatment decreased the AC stimulatory effects of β3-agonists to their levels in the control. Since functional disruption of the adrenergic agonist-sensitive ACSS can lead to metabolic syndrome and DM2, the recovery of this system by the I-I treatment offers one of the ways to correct these diseases and their complications in the nervous and cardiovascular systems.

In this work we analyzed the levels of functional activity of dopaminergic, GABA-ergic and glutamatergic neurons in the nigrostriatal system of control Wistar rats and Krushinsky-Molodkina (KM) rats prone to audiogenic seizures. In KM rats we have revealed disturbed activity of GABA- and dopaminergic neurons in substania nigra whereas the level of glutamatergic neurotransmission remained unchanged. We have also observed no significant differences in GAD65/67 and phospho-tyrosine hydroxylase contents in the striatum of KM and control Wistar rats. However, a high level of D1 dopamine receptor and a decreased level of D2 receptor found can mediate the upregulation of glutamatergic neurotransmission. Indeed, the expression of vesicular glutamate transporter type 2 (VGlut2) and NR2B subunit of NMDA receptor was increased in the striatum of KM rats. In striatal glutamatergic fibers phosphorylated ERK1/2 kinases have been revealed; at the same time, in KM rats an increased ERK1/2 activity has been detected both in striatum and substantia nigra. This finding correlated with activation of exocytosis rate as evidenced by downregulation of SNAP25 level. Apart from other reasons, the activation of glutamatergic system may be a result of disruption of the inhibitory effect of the dopamine- and GABAergic systems of substantia nigra that innervate striatum. We suppose that the increased activity of striatal glutamatergic neurons of KM rats without an adequate inhibition by GABA- and dopaminergic systems may be one of the reasons of high convulsive susceptibility in KM rats.

The goal of this study was to examine the plasticity of the thermal reaction norms for development in the European Peacock butterfly Inachis io under the effect of different photoperiodic conditions and group versus individual maintenance. The overwintered imagoes were collected in Old Peterhof (near Saint-Petersburg) in May, 2010 and 2012-2013. 12 experimental regimens were used: 4 temperatures (16, 18, 20 and 22 degrees C) and 3 photoperiods (12, 18 and 22 h of light a day). It was found that under short-day conditions (12 h) the caterpillars developed a little faster than under long-day ones (22 h). The developmental temperature thresholds in these two cases did not differ. A linear regression coefficient characterizing thermal sensitivity of development was significantly higher only in males with their development affected by short-day photoperiod stronger than in females. At 18-h day length, the caterpillar development was less temperature-sensitive and characterized by a lower threshold than in shorter and longer days. The influence of short-day photoperiod on the caterpillar development manifested itself most distinctly in the emerging pupae' weight changes: in all the temperature regimens the pupae were lighter at short than at long days. The pupal weight increased as the temperature rose. The found dependence does not agree with the "temperature-size rule". Individual rearing led to a longer duration and lower thermal sensitivity of caterpillar and pupal development as well as to a reduced weight of the pupae. Individual rearing had a stronger impact on the mineral of females than males.

This study addresses the potentialities of flow cytometry in analyzing the composition of circulating hemocyte populations in the ascidian Halocynthia aurantium (Pallas, 1787) both using monoclonal antibodies (mAbs) against some human leukocyte conservative adhesion molecules and without mAbs. Flow cytometry, based on the assessment of forward and side scattering revealed five hemocyte populations. From the wide panel of antibodies against human leukocyte adhesion molecules (CD15, CD29, CD34, CD54, CD62L, CD62P, CD90, CD94, CD117, CD 166), only two mAbs (against CD54, CD90) displayed cross-reactivity with the H. aurantium hemocyte surface antigens. Distribution patterns of these antigens across the hemocyte populations have been analyzed.

The effect of Li+ on the frog Rana temporaria myocardium and its influence on the ion transport in the rat heart mitochondria (RHM) were studied. Li+ added to the normal Ringer solution (Li(+)-R) was found to attenuate myocardial tension, decrease the maximal rate of tension development and its half-relaxation time. Comparison of the cardiac muscle contraction parameters in the Li(+)-R with the effect of the voltage-gated Ca(2+)-channels (Cav1.2), verapamil and CdCl2, showed that the negative inotropic effect of the Na+ replacement by Li+ in the limited intermembrane ("fuzzy") space is underlain by the blocking of Ca2+ influx into the myoplasm via the reverse Ca2+/Na(+)-exchanger in the plasma membrane (PM). This, in turn, prevents Ca(2+)-induced massive Ca2+ release into the myoplasm via the RYR2-channels in the sarcoplasmic reticulum (SR) leading in aggregate to suppression of Ca(2+)-dependent myocardial contractions. In the experimental studies of the Li+ effect on the RHM it was established that Li+ just slightly increases the passive permeability of the inner mitochondrial membrane (IMM) for K+ and H+ and decreases the intensity of ion pumping out of the energized mitochondrial matrix to the external medium. This may also indicate the lack of relationship between the mitochondrial oxidative processes and the reduction in the myocardial contractile activity under the Na+ replacement by Li+.

The effect of different levels of hypoxia on viability, physiological condition and morphometric characters of the honey bee (Apis mellifera L.) workers at the prepupal and pupal stages was traced. A high tolerance of the honey bee brood to hypoxia was established. Excess CO2 by more than two orders of magnitude relative to its content in the atmosphere and beehive at the optimal temperature for a bee family exhibits a mimimum lethality. Morphological anomalies manifested as wing and proboscis hypoplasia were found at the CO2 concentration raised by 10-15 %. This leads to a reduction on the number of frenulum hooks on the hind wings and affects their asymmetry variability. The wing lengths and the number of frenulum books are in inverse while masses of the head, thorax and abdomen--in direct relationship with the CO2 concentration.

This study reports the dynamics of changes in postnatal ontogenesis of the activity of soluble and membrane-bound forms of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in sensorimotor cortex of rats as well as the pattern of their changes after prenatal hypoxia (E14, 7% O2, 3 h) or acute hypoxia in adult animals (4 months, 7% O2, 3 h). In normally developing rats the activity of the membrane-bound AChE form in the sensorimotor cortex gradually increased up to the end of the first month after birth and remained at this high level during all further postnatal ontogenesis, while the activity of the soluble form of AChE reached its maximum on the 10th day after birth and decreased significantly by the end of the first month. In animals exposed to prenatal hypoxia the activity both of the soluble and membrane bound forms of AChE during the first two weeks after birth was 20-25% lower, as compared to controls but increased by the end of the first month and even exceeded the control values remaining increased up to old age (1.5 years). The activity of both BChE forms in rat sensorimotor cortex at all stages of postnatal ontogenesis was significantly lower than of AChE, although the dynamics of their changes was similar to that of AChE. Prenatal hypoxia led to a decrease in the activity of the membrane-bound form of BChE, as compared to controls, practically at all developmental stages studied, but was higher at the end of the first month after birth. At the same time, the activity of the soluble form of BChE was decreased only on the 20th day of development, as compared to the control, but increased from the end of the first month of life onwards. Acute hypoxia in adult rats also led to a decrease in the activity of both forms of AChE and BChE in the sensorimotor cortex but the dynamics of these changes was different for each enzyme. Thus, insufficient oxygen supply to the nervous tissue at different stages of ontogenesis has a significant effect on the activity and ratio of various forms of cholinesterases exhibiting either growth factor or signaling properties. This may lead to changes in brain development and formation of behavioural reactions, including learning and memory, and also increase the risk of development of the sporadic form of Alzheimer's disease (AD)--one of the most common neurodegenerative diseases of advanced age. This study expands our knowledge of the properties of brain cholinesterases under normal and pathological conditions and may be useful for developing new approaches towards prevention and treatment of AD.

Some catalytic and kinetic properties of pyruvate kinase (PK, EC 2.7.1.40) isolated from the heart and skeletal muscles of rabbits and hares with a 9-16-fold purification were studied. The initial specific activity of the enzyme in hare heart homogenates was 66% and in skeletal muscles 25% as high as in respective rabbit tissues. Temperature optimums and thermostability of PK from hare tissues were higher as compared with those in rabbits. From the comparison of K(M) (S0.5) values it follows that hare skeletal muscle PK exhibits a highest affinity to phosphoenol pyruvate, but lowest to ADP, as compared with rabbit skeletal muscle PK. Moreover, PK from both hare tissues exhibits a positive kinetic cooperativity (Hill coefficient > 1.35) of the phosphoenol pyruvate and ADP binding sites. In contrast to PK from rabbit tissues, the enzyme from the hare heart and muscles PK is presented by its allosteric isoform which might by advantageous under extreme conditions of the hare's habitation.