Hypoxic hypoxia

Following the action of extraordinary stimulants (hypoxic hypoxia, hypoxia + hyperoxia, hypodynamia + hyperthermia), animals demonstrate an accumulation of malonic dialdehyde with a simultaneous fall of antiradical activity of the liver tissue. A preliminary introduction to rats of acetylene amine 3,4,5-tris(morpho-linopropynyl)-l-methylpyrazole 103 and also of tocopherol antioxidant and gutumine antihypoxant averts activation of the lipid peroxidation processes. The inhibition of peroxidation with this agent is mediated by stabilization of ly-zosomal and mitochondrial membranes. Unsaturated amines prevent destruction of the organelle membranes provoked by UV irradiation and incubation at 37°C (pH4.7)(78MIl). 

Gulaya, N.M., Kuzmenko, A.I., Margitich, V.M. et al. Long-chain N-acylethanolamines inhibit lipid peroxidation in rat liver mitochondria under acute hypoxic hypoxia. Chem. Phys. Lipids. 1998 97 49-54. 

In late gestation, the fetal cardiovascular response to hypoxia is typified by a rapid, transient bradycardia and increased heart rate variability (21,22). The bradycardia reaches a nadir approximately 1-2 min after the onset of the hypoxic insult (15,23) and, presumably, economizes on myocardial oxygen consumption. Fetal hypoxic bradycardia occurs at the onset of hypoxic hypoxia (5), umbilical cord occlusion (24,25), and uterine artery occlusion (26)— the three most common experimental hypoxic challenges. 

More recently, successful reinnervation of carotid body glomus cells, changes in the electrical properties, pharmacological sensitivity, and reappearance of hypoxic chemosensitivity in petrosal ganglion cells have been reported when explants of both organs are cultured together (31-35). Petrosal ganghon neurons acutely disconnected from the carotid body and superfused in vitro are not excited by hypoxic hypoxia (36). 

---