Alterations of the respiratory system in heart failure

The review discusses mechanisms for the development of the pathology of the respiratory system in patients with CHF, such as various types of periodic respiration, pulmonary hypertension due to the pathology of the left chambers of the heart, and remodeling of the respiratory musculature. The role of chemo- and baroreceptors of the carotid zone, as well as the hyperactivation of the respiratory muscle metaboreflex in the development of the pathology of the respiratory system, and the mediated exacerbation of CHF are discussed.

Correction of pathological periodic respiration with Mexidol in rats

В острых опытах на наркотизированных самцах беспородных белых крыс изучали возможность применения метаболической терапии мексидолом для коррекции периодического патологического дыхания, вызванного оксибутиратом. В интервале доз 40-200 мг/кг мексидол нормализовал дыхание, причем продолжительность нормализации зависела от его концентрации. При использовании мексидола в дозах 100-200 мг/кг длительность сохранения нормального ритмического дыхания составляла несколько часов. Проведенное исследование показало, что мексидол является эффективным средством коррекции периодического патологического дыхания с задержками в фазе спокойного выдоха, способный нормализовать дыхательный ритм на протяжении нескольких часов. A possibility of using the Mexidol metabolic therapy for correction of hydroxybutyrate-provoked periodic pathological respiration was evaluated in acute experiments on anesthetized white mongrel male rats. Mexidol at doses of 40-200 mg/kg dose-dependently normalized the respiratory rhythm. Mexidol at doses of 100-200 mg/kg maintained the normal, rhythmic respiration for several hours. Therefore, Mexidol is an effective drug for correction of the periodic pathological breathing with arrest in the quiet expiratory phase, which normalizes generation of the respiratory rhythm for several hours.

Periodic respiration of gill-breathing fishes

Rhythmic and arrhythmic patterns of breathing are common among gill-breathing fishes. Irregular, short bouts of apnea occur in most fishes during feeding, while long apneic periods are routine for many open-water fishes such as scombrids, which ram ventilate during cruise swimming. During ram ventilation, the work of gill ventilation is transferred from the respiratory to the swimming musculature, with energy savings due to reductions in drag and inertial losses. Noncontinuous swimmers, such as some benthic and midwater marine and freshwater species, seldom cease rhythmic respiratory movements or resort to ram ventilation. When quiescent, they may adopt patterns of secondary cycling, alternating between respiratory pauses and short periods of rhythmic branchial pumping. Types and locations of chemo- and mechano-receptors that trigger changes in respiratory patterns of fish are being identified, as are the reflex pathways linking them to brainstem respiratory centers. A new mechanoreceptor is described that overlies the adductor mandibulae jaw muscles and may be of use in the modulation of cyclic respiratory movements. Respiratory switching control between rhythmic and ram gill ventilation is discussed.