Enrique Valdivia

Conformational basis of energy transduction in membrane systems VIII. Configurational changes of mitochondria: In Situ andIn Vitro

A method has been devised for the study of configurational changes in mitochondriain situ during the transition from nonenergized to energized conditions. The method depends upon the following component features: (a) subdivision of the tissue into finely diced sections; (b) the use of a modified Krebs-Ringer phosphate solution as the suspending medium; (c) aerobic conditions as the tactic for imposing the energized state; (d) anaerobic conditions or the presence of uncoupler under aerobic conditions as the tactic for imposing the nonenergized state; and (e) rapid fixation of the diced sections by addition of a mixture of formaldehyde and glutaraldehyde at a controlled temperature. Regardless of the tissue of source (heart, liver, skeletal muscle, retina, kidney) or the species (beef, rat, canary), all mitochondria show unambiguous configurational changes during the transition from nonenergized to energized conditions. The present study has revealed various optional features of the configurational states. Thus, there are two nonenergized configurations of the crista—orthodox and aggregated. The osmotic pressure of the suspending medium determines which nonenergized configuration will be observed. There are at least two variant forms of the energized-twisted configuration—tubular and zigzag. Again the osmotic pressure of the medium is an important factor in determining the form of the crista in the energized-twisted configuration. Mitochondria, such as those of heart muscle with relatively little matrix protein, show the clearest and most regular configurational changes, whereas mitochondria, such as those of liver with an abundance of matrix protein, show a more complex and less regular pattern of configurational change. From this comparative study of mitochondriain situ, it can be concluded that no exceptions have been found to the generalization that changes in configurational state of the cristae accompany changes in the energy state; this exact correlation provides additional support for the hypothesis of the conformational basis of energy transduction in the mitochondrion.

Experimental Interstitial Pulmonary Edema

membrane formation, hemorrhage, arteritis, obstructive vascular lesions, metaplastic and hyperplastic alveolar epithelium are observed in microscopic sections of the lungs of rats poisoned with monocrotaline. The described pulmonary lesions all precede right ventricular hypertrophy, which is presumably secondary to pulmonary hypertension. Previous studies have demonstrated these alterations to follow repeated injections or prolonged feeding without

Right Ventricular Hypertrophy in Guinea Pigs Exposed to Simulated High Altitude

Guinea pigs exposed to simulated altitudes of 18,000 feet developed right heart dilatation followed by hypertrophy, more conspicuous in the infundibular area of the right ventricle. Under the described experimental conditions, pulmonary artery hypertension may be the etiologic factor.

Energized configurations of heart mitochondria in situ

Changes in the configurational state of the cristal membranes of rat heart mitochondria within the living cell can be induced by imposing energizing conditions. An exact correlation has been established between the configurational states of the cristal membrane and the energy states of the mitochondrion. The configurational changes observed in mitochondria in situ are comparable to those established for beef heart mitochondria in vitro and are consistent with the postulate of the conformational basis of energy transductions in membrane systems. The formation of paracrystalline arrays is one of the noteworthy features of configurational changes of mitochondria in situ.

Emphysema with hereditary alpha-1 antitrypsin deficiency masquerading as asthma

Abstract Ten patients among 11 persons homozygous for hereditary alpha-1 antitrypsin deficiency had chronic obstructive lung disease with exertional dyspnea as the prime symptom. Some also had wheezing and sputum production. Early in the course of the illness 5 of the patients were erroneously considered to have asthma. One patient was unique, lacking detectable levels at all. Assay of serum of family members was consistent with an autosomal codominant mode of inheritance in all families. Autopsy of the 2 patients who died showed extensive panacinar emphysema. One had in addition peribronchial inflammation, extensive squamous metaplasia of the tracheal and bronchial epithelium, and distinct degenerative changes of the tracheobronchial cartilage plaques.

The isolation and characterization of the lamellar body of bovine lung.

Abstract A novel procedure for preparing intact lamellar bodies from bovine 3 lung has been developed. The procedure consists of enzymatic digestion 4 of ground-lung tissue, with Nagarse, homogenization with a loosely-fitting pestle and then differential and density gradient separation of the various cellular fractions as the basis for selection of the lamellar body fraction.

Isolation And Identification op Pulmonary Lamellar Bodies from Guinea Pigs

Abstract A method has been developed for isolation of different organelles from the alveolar lining cells of guinea pig lungs. Ultrastructure identification of the lamellar body fraction is established by electron microscopy. Surface tension measurements have been determined.

Fatty Change of the Granular Pneumocyte

Fat vacuoles develop in the granular pneumocytes of guinea pigs exposed to severe hypoxia in low-pressure chambers. The ostiniophilic lamellar bodies are apparently reduced in size and decreased in number. The fatty change of the granular pneumocyte may represent a metabolic alteration and interfere with the production of surfactant. This hypoxic lesion of the pneumocyte may be a significant factor in high-altitude pulmonary insufficiency.

Mitochondria uncoupling effect of halothane dependent on magnesium

Abstract Halothane accelerates the respiration of beef heart mitochondria (HBHM) in metabolic state four in the presence of succinate as the substrate. This effect is dependent on the presence of magnesium ions in the medium and is also related to an increase of ATPase activity and a decrease of ATP available for the cytosol. The anesthetic also inhibits energy dependent processes, i.e. valinomycin induced mitochondrial swelling and potassium accumulation.

Electrophoresis of isolated mitochondria

Abstract Isolated respiring mitochondria suspended in an isotonic medium migrate to the anode when they are exposed to an electric field. A simple method has been devised to visualize this electrical property of the organelles utilizing a modified zone electrophoresis technique. Uncouplers of oxidative phosphorylation inhibit this anaphoretic property of isolated mitochondria.