Peculiarities of the influence of mitochondrial ATP-dependent K+ channels activation on the function of external respiration under experimental pneumonia

The studies were performed on male Wistar rats weighing 250-270 with experimental pneumonia (EP) induced by the method of A.M. Kulik. The animals were divided into the following groups: 1 – control; 2 - experimental pneumonia; 3 (first experimental group) - animals, which in parallel with the simulation of pneumonia were intraperitoneally administered uridine at a dose of 0.3 mg/100 g of body weight (daily within 1 week); 4 (second experimental group) - animals in which uridine was administered daily starting from day 4 (at the peak of pneumonia). Animals with EP were examined at 5th (n = 10), 9th (n = 8) and 12th (n = 6) days of the disease development, as well as 1 (n = 5) and 2 (n = 5) months after EP modeling. It was shown that in the first experimental group on the 5th day of EP development, an isoventilator restructuring of respiration was observed. In this group, from day 12 to the end of the study, there was a stenoventilator restructuring of breathing, which was characterized by an increase in tidal volume, alveolar ventilation, oxygen consumption and, accordingly, an increase in oxygen extraction from the alveoli and in the oxygen effect of the respiratory cycle. It can be assumed that in this group, an increase in the intensity of metabolism is provided by the effective activity of the respiratory system. In the second experimental group, isoventilator changes in respiration were observed with a gradual decrease in oxygen consumption and other indicators of the respiratory system efficiency. After 2 months, these changes became significant. Thus, we can talk about significant differences in the effect of uridine on the function of external respiration (i.e., apparently, on the activity of the mitochondrial ATP-dependent K+ channel) during EP, which depended on the period of onset of uridine administration. Application of uridine immediately (1st experimental group) looks more effective and even has a stimulating effect on the respiratory function over a long period of experiment. The administration of uridine starting from the 4 partially normalizes the respiration parameters. However, after 1 month there is a depression of the functions of the respiratory system, which, probably, may further worsen. The reasons for the differences in the identified dynamics require further investigation.

BKCA CHANNELS MEDIATE THE EFFECTS OF DOCOSAHEXAENOIC ACID ON THE RESPIRATION PARAMETERS OF MYOCARDIAL MITOCHONDRIA AT HIGH CALCIUM CONCENTRATIONS

Omega-3 polyunsaturated fatty acids (PUFA) provide protection against myocardial damage in ischemia-reperfusion. However, the mechanisms that provide cardioprotection are not fully understood. In this study, we investigated the effect of docosahexaenoic acid (DHA), a member of omega -3 PUFA, on mitochondrial respiration parameters and the role of mitochondrial calcium-dependent potassium channels of large conductance (ВКСа) in the implementation of these effects. Using the patch-clamp method, it was shown that functional ВКСа channels are expressed in the inner mitochondrial membrane of cardiac cells and their activity increases with the addition of DHA. We investigated the role of mitochondrial ВКСа channels in the regulation of mitochondrial respiratory processes. In experiments with isolated mitochondria from rat hearts, we showed that DHA prevented an increase in the respiratory rate of mitochondria in the V4 state and a decrease in the respiratory control elicited by addition of 10 μM Ca2+. Qualitatively the same effect was caused by NS1619, the ВКСа opener. In the presence of 10 μM Ca2+, the ВКСа channel inhibitor paxilin (1 μM) prevented the protective effect of DHA and NS1619 on the parameters of respiratory control. We conclude that mitochondrial ВКСа channels are involved in the implementation of the effects of DHA on mitochondrial respiration.

Comparison of respiratory parameters with and without mouth guard in Karate PlayersKaratecilerde ağız koruyuculu ve ağız koruyucusuz ölçülen solunum parametrelerinin karşılaştırılması

This study aimed to examine the effects of using a mouth guard in Karate on respiration parameters. The study sample consisted of 10 volunteer elite male karate athletes who participated in the National Karate Team and still practice the sport (24.4±6.3years, 176.2±7.4 cm, 71±4.1 kg). The athletes were exposed to respiration tests without and with mouth guard with 2 days interval that give FVC, FEV1, MVV and PEF values. In the light of the found parameters, were no meaningful differences were observed in measurements of parameters between the measurements with and without a mouth guard (p > 0.05). The athletes continued their routine training between pre-test and post-test. In conclusion it was seen that the use of mouth guard did not directly affect the breathing performance.Extended English abstract is in the end of Full Text PDF (TURKISH) file.ÖzetBu çalışmada Karate sporundaki ağız koruyucusu kullanımının solunum parametrelerine etkisini incelemek amaçlanmıştır. Çalışmaya Karate Milli Takımı’nda yer almış ve aktif spor yaşantısı devam eden gönüllü 10 erkek elit karate sporcusu (24,4±6,3yıl, 176,2±7,4 cm, 71±4,1 kg) dahil edilmiştir. Sporcular FVC, FEV1 MVV, PEF değerlerinin elde edildiği solunum testlerine 2 gün ara ile dişliksiz ve dişlikli olarak katılmıştır. Kaydedilen parametreler ışığında, dişlikli ve dişliksiz ölçümler arasında istatistiksel açıdan anlamlı bir ilişki gözlenmemiştir (p > 0.05). Sporcular ön test ve son test arası rutin antrenmanlarına devam etmiştir. Sonuç olarak, dişlik kullanımının solunum performansını direkt olarak etkilemediği görülmüştür.