Mitochondrial ATPase activity and membrane fluidity changes in rat liver in response to intoxication with Buckthorn (Karwinskia humboldtiana)

BACKGROUND: Karwinskia humboldtiana (Kh) is a poisonous plant of the rhamnacea family. To elucidate some of the subcellular effects of Kh toxicity, membrane fluidity and ATPase activities as hydrolytic and as proton-pumping activity were assessed in rat liver submitochondrial particles. Rats were randomly assigned into control non-treated group and groups that received 1,1.5 and 2 g/Kg body weight of dry powder of Kh fruit, respectively. Rats were euthanized at day 1 and 7 after treatment. RESULTS: Rats under Kh treatment at all dose levels tested, does not developed any neurologic symptoms. However, we detected alterations in membrane fluidity and ATPase activity. Lower dose of Kh on day 1 after treatment induced higher mitochondrial membrane fluidity than control group. This change was strongly correlated with increased ATPase activity and pH gradient driven by ATP hydrolysis. On the other hand, membrane fluidity was hardly affected on day 7 after treatment with Kh. Surprisingly, the pH gradient driven by ATPase activity was significantly higher than controls despite an diminution of the hydrolytic activity of ATPase. CONCLUSIONS: The changes in ATPase activity and pH gradient driven by ATPase activity suggest an adaptive condition whereby the fluidity of the membrane is altered.

Effect of Combined Aerobic and Anaerobic Training on Hemodynamic Response, Serum Oxidative Stress Markers and Platelet ATP Synthase Activities in Patients with Coronary Heart Disease: A Pilot Study.

Background: The overall aim of this work was to study the impact of combined aerobic and anaerobic training in relation to hemodynamic response (heart rate, systolic blood pressure, and double product), serum oxidative stress markers (lipoperoxides, nitrites-nitrates) and platelet ATP synthase activities in patients with coronary heart disease. Materials and Methods: Ten subjects, 9 male and 1 female, (mean age 57.7±7.2 years) with coronary heart disease participated in this study. Patients performed combined aerobic and anaerobic exercise for 24 sessions (three times a week). Results: The results suggest myocardium adaptations, manifested in the reduction of heart rate with increased workloads and increased double product [(heart rate) x (systolic blood pressure)] according to the intensity, frequency and duration of training. The ATP synthesis rate was significantly increased at session 3 (post-exercise) compared to session 1 (pre exercise). Furthermore, rate of ATP hydrolysis was significantly decreased at session 24 (post-exercise 3) compared to session 1 (post-exercise 1). Serum lipid peroxidation products and nitric oxide catabolites were significantly diminished at session 24 (pre-exercise). Conclusion: In some patients hemodynamic responses showed improvements in response to exercise. The exercise sessions induced lower levels of lipid peroxidation products, nitric oxide catabolites and ATPase activity. Conversely, ATP synthase activity showed higher values at the end of the experiment. These results confirm the beneficial effect of combined aerobic and anaerobic exercise.

Spinal Muscular Atrophy: Review of a Child Onset Disease.

Spinal Muscular Atrophy (SMA) is a group of inherited disorders that involve mainly bulbar and spinal motor neurons; causing muscle weakness and atrophy of proximal and symmetrical predominantly in lower extremities, without affecting the facial muscles and the intellectual ability. It is also unclear if SMA is a developmental or a neurodegenerative disease and occurs predominantly in childhood. The continuous clinical spectrum of SMA has been divided into 3 types based on the age at onset and highest motor milestones achieved. SMA type I was described by Hoffman in 1894 and in 1900 was reported as a disease characterized by hypotonia during the first 3 months of life, as well, is considered as the leading cause of death in children under two years of age among genetic diseases worldwide. SMA type II patients can achieve sitting but not walking. While SMA type III patients achieve full milestones with a progressive loss of walking ability. Deterioration in muscle strength and motor function eventually occurs in SMA type II and III. SMA occurs due to depletion of SMN, a ubiquitously expressed protein, which in all cells regulates RNA biogenesis and splicing through its role in the assembly of small nuclear ribonucleoprotein (snRNP) complexes.

Neurotoxicity of Dextrorphan

Background. The noncompetitive NMDA antagonists phencyclidine (PCP) and dizocilpine (MK-801) have been considered for use as neuroprotective therapeutic agents, although both produce injury in neurons of cingulate and retrosplenial cortices in rodents. The low-affinity, noncompetitive NMDA antagonist dextrorphan has been considered for use as a neuroprotective therapeutic drug. The aim of the present work was to evaluate the neurotoxicity of dextrorphan. Methods. Sprague-Dawley male rats were used and injected with either saline or dextorphan (30 mg/kg i.p.). The animals were sacrificed 30 min later, and the brain was examined for histopathological changes. Results. After. systemic administration of the drug, hyperchromatic and shrunken nuclei with chromatin condensation and disruption were observed. Also. granular and vacuolated cytoplasm was apparent in pyramidal neurons in the retrosplenial (posterior cingulate) cortex. Status spongious (spongy degeneration) of the neuropil was also detected. Conclusions. Morphological changes are similar to those described previously, which are induced by high-affinity, noncompetitive NMDA antagonists, such as MK-801

La glándula de Harder: un transductor neuroinmunoendrocrino / The Harderian gland: neuroinmunoendrocrine transductor

La glándula de Harder es una glándula túbulo-alveolar localizada en la parte posterior de la órbita ocular de animales que poseen membrana nictitante. En estos mamiferos la glándula contiene una gran cantidad de lípidos. La glándula de Harder de roedores contiene un pigmento café rojizo, el cual ha sido identificado como porfirina. Las funciones de la glándula de Harder son; síntesis y liberación de ferhormonas, fotoprotección y termorregulación, osmoprotección y se le ha propuesto además un papel inmunoendocrino