Effect of emergent and long-term adaptation to physical strength on the resistance of Ca-transporting system of myocardial sarcoplasmic reticulum

Experiments were carried out on rats adapted to physical exercise (on the next day after completion of 4, 11, 15, and 30 swimming sessions). Catalase and superoxide dismutase activities were similar in all rats. The resistance of Ca transport into sarcoplasmic reticulum to high Ca²⁺ concentrations and autooxidaton increased starting from 4 swimming sessions, and to thermal inactivation from 11 sessions; the maximum resistance was attained after 15 sessions 1.5- to 2-fold surpassing the initial level. Maximum initial rate of Ca²⁺-transport (155% of the control) was observed after 30 swimming sessions. In acute physical strength and at the initial stages of adaptation (4 swimming sessions) functional properties of myocardial Ca-transporting system were preserved under optimal conditions, but can be readily disturbed by adverse factors. Translatedfrom Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 1, pp. 40–44, January, 1998 Original     

The effect of delta-sleep-inducing peptide on the Ca-transporting system of the sarcoplasmic reticulum and activity of the myocardial antioxidant enzymes

It is demonstrated that immobilization stress against the background of lowered catalase activity impairs the function of the sarcoplasmic reticulum Ca pump, particularly at high Ca²⁺ levels. the membranes of intracellular Ca²⁺ depots are destroyed much more rapidly than in the control, which results in Ca²⁺ release. Administration of delta sleep-inducing peptide to control animals results in a 30% increase in catalase activity for an unchanged level of superoxide dismusase and markedly improves the function of the Ca-transporting system at elevated levels of free Ca²⁺. A long-term stress after administration of the peptide not only causes no damage to the Ca-transporting system but actually increases its efficiency (compared with the control) at a high catalase level. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 3, pp. 248–251, March, 1996 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Effect of a polyunsaturated fatty acid-enriched diet on the state of the Ca-transporting system of the sarcoplasmic reticulum in the myocardium

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 10, pp. 350–352, October, 1993     

Opposite effect of adaptation to physical exercise on myocardium and skeletal muscle. Ca-transporting system of the sarcoplasmic reticulum and antioxidant defense enzymes

Adaptation to physical exercise was achieved via 60-min sessions of swimming at 32°C for 45 days, the duration of swimming being increased from 15 to 60 min during the first 14 days. Under these conditions, against the background of reduced catalase and superoxide dismutase activity the Ca-transporting system of the sarcoplasmic reticulum in the heart is shown to work more effectively: Ca²⁺ transport is characterized by a higher initial rate and is inactivated 1.5 times more slowly byin vitro-induced lipid peroxidation and not inhibited by high concentrations of free Ca²⁺. In the skeletal muscle, on the other hand, catalase and superoxide dismutase activity rise, but this does not improve the functioning of the Ca pump: the initial rate of Ca²⁺ transport drops, its resistance to autooxidation is not increased in comparison with the control, and the resistance of the Ca²⁺-transporting system to the inhibiting influence of free Ca²⁺ is lowered. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, No. 6, pp. 623–628, June, 1996     

Adaptation to stress enhances the resistance of the calcium pump in rat myocardial sarcoplasmic reticulum

The development of adaptation during stress is studied. At the early stages, adaptation exerts no protective effect: the activities of superoxide dismutase and catalase and the resistance and the Ca-transporting system of the myocardial sarcoplasmic reticulum to heat inactivation and high calcium concentrations decline. At the end of adaptation, superoxide dismutase and catalase activities increase, the function of the sarcoplasmic reticulum Catransporting system is improved, and the resistance of this system to high Ca concentrations increases compared with that in the control (1.4-fold) and during the early stages of adaptation (1.6-fold). The resistance to heat inactivation increased 1.5-fold compared with the control. Three days after the completion of adaptation, the activities of these enzymes and the resistance of Ca transport to heat inactivation and high Ca concentrations are lower than immediately after adaptation, but higher than in the control group and during the early adaptation period. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 272–276, March, 1997     

Effect of adaptation to moderate physical loads on the increased resistance of the isolated heart to ischemia and reperfusion

Adaptation to physical loads elicits pronounced anti-ischemic and antireperfusion effects on the isolated heart. By the 20th min of total ischemia contracture in the hearts of adapted animals is much less than that in the control group. During reperfusion of hearts from adapted animals the degree of restoration of the contractile force was 6-fold higher, contracture was lesser, and the total period of tachycardia and fibrillation were 3-fold shorter than in the control. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 1, pp. 25–27, January, 1995 Presented by S. S. Debov, Member of the Russian Academy of Medical Sciences     

Ca2+ transport in the myocardial sarcoplasmic reticulum of rats during antiorthostatic off-loading and during readaptation

The rate of Ca²⁺ accumulation in the myocardial sarcoplasmic reticulum is studied in experiments on rats under conditions of hind paw functional off-loading by suspending animals by the tail for 1 to 40 days, as well as during a 2-week period of readaptation after a 40-day load relief. The rate of Ca²⁺ transport in the myocardial sarcoplasmic reticulum reliably drops (by 33%) after 40 days of suspension. At earlier stages of off-loading Ca-pump activity in the sarcoplasmic reticulum does not change reliably. After resumption of the loads in animals suspended for 40 days, the transporting function of the myocardial sarcoplasmic reticulum rapidly reverts to the control level, which is indicative of a reversible pattern of load relief-induced changes in the rate of Ca²⁺ transport. Translated fromByulleten' Eksperimental'noi Biologii i Meditsity, Vol. 118, N ^o 12, pp. 596–599, December, 1994 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Ca2+ transport of the skeletal muscle sarcoplasmic reticulum during readaptation of rats after a 40-day load relief on the hind paws

The rate of Ca²⁺ accumulation in the sarcoplasmic reticulum of the skeletal muscle (m. gastrocnemius lateralis, m. vastus medialis, andm. soleus) is studied in rats under conditions of functional off-loading of the hind paws (suspending animals by the tail). The rate of Ca²⁺ transport in the sarcoplasmic reticulum is shown to be stepped up in all these muscles. In the sarcoplasmic reticulum ofm. gastrocnemius lateralis andm. vastus medialis the Ca²⁺ transport rate reliably drops, which does not occur inm. soleus. During a 2-week period of readaptation of animals suspended for 40 days, the Ca²⁺-transporting function of them. soleus sarcoplasmic reticulum gradually recovers to reach the control values, whereas the time course of recovery of Ca²⁺-pump activity in the sarcoplasmic reticulum ofm. gastrocnemius lateralis andm. vastus medialis has a phasic pattern. Translated fromByulleten' Eksperimental'noi Biologii i Meditsity, Vol. 118, N ^o 12, pp. 591–595, December, 1994 Presented by A. I. Grigor'ev, Member of the Russian Academy of Medical Sciences     

Vascular thrombogenicity and thromboresistance during postischemic reperfusion

Responsiveness, thrombogenicity, and thromboresistance of mesenteric microvessels were studied in rats during postischemic reperfusion of the intestine, brain, and hind limb. Irrespective to localization of the ischemized organ, the mesenteric microvessels increased responsiveness and decreased thromboresistance. Vascular thrombogenicity depended on the localization of ischemia. During cerebral reperfusion, thrombogenicity of some venules was decreased against the background of its general increase in arterioles. Microvascular disturbances and predominantly related to perturbations in nitric oxide synthesis. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 8, pp. 168–171, August, 1999     

Prevention of ischemic disturbances of contractile function of isolated heart by short-term total ischemia episodes

Short-term total ischemia episodes restrict the drop in the force and rate of contractions of isolated rat heart during long-term reperfusion period after long-term ischemia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 5, pp. 512–514, May, 1997     

Effect of semax and semax-heparin mixture on isolated heart activity after total ischemia in rats

Semax administered after 40-min total ischemia of isolated heart improved the recovery of heart rate and reduced myocardial contracture. When administered prior to ischemia, Semax exerted a negative effect on recovery of heart contractility. Semax-heparin mixture significantly improved the recovery of cardiac indices (end-diastolic pressure, heart rate, and relaxation rate) irrespective of administration schedule. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 11, pp. 494–496, November, 1999     

Myocardial protection by pantothenic acid derivatives in heart model with experimental ischemia and reperfusion

Laboratory of Functional Biochemistry of the Myocardium, Latvian Medical Academy, Riga. (Presented by Academician S. E. Severin, Academy of Medical Sciences.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 4, pp. 373–375, April, 1992.     

Seasonal differences in the development of heightened resistance of the isolated heart during adaptation to physical exercise

Substantial seasonal differences are found in the development of the cardioprotective effect of adaptation to physical exercise: in winter such adaptation results in an increase of the resistance of the isolated heart to the contracture and arrhythmogenic effects of ischemia and reperfusion, while in summer the anticontracture effect is absent and the antiarrythmic effect is significantly lowered. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 299–301, September, 1995 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Analysis of fluctuations of capillary blood flow in the cortex of rat kidneys during ischemia

The dynamics of fluctuations of capillary blood flow in the cortex of rat kidneys under conditions of transient occlusion of renal arteries and veins or simultaneous occlusion of afferent and efferent vessels was studied by laser Doppler flowmetry. The initial variability of blood flow in the right kidney was higher than in the left kidney. The most pronounced changes in the right kidney were observed during occlusion and subsequent recirculation. In the left kidney, the most pronounced changes were found during occlusion and after arterial occlusion. Spectral analysis gave similar results. The recovery of renal blood flow after transient venous occlusion took longer time than after arterial occlusion (especially in the right kidney). Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 8, pp. 148–152, August, 1999     

Stress-induced modification of the sarcoplasmic reticulum Ca transport system of the heart and its resistance to endogenous damaging factors

Research Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy or Medical Sciences of the USSR G. N. Kryzhanovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 9, pp. 271–274, September, 1989.     

Changes in Kupffer cells after reversible ischemia in rat liver

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol.116, N ^o 11, pp. 548–550, November, 1993