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Biomedical subjects

N Banchero

Publications and source records attributed to N Banchero.

At least 55 records · Page 3Linked to original sources
PubMed1977

Visualization of capillaries in skeletal muscle by the ATPase reaction.

A simple and reliable technique for the visualization of capillaries in skeletal muscel of dogs, guinea pigs and rats is decribed. 10--20 micrometer frozen sections were incubated in a medium containing Ca2+ and ATP following acid preincubation (pH 3.8--4.2). The capillaries stained in black and were readily seen surrounding the muscle fibers. Serial sections were also treated for alkaline phosphatase. Values for capillary density using both methods were not different.

Adenosine Triphosphatases↗
PubMed1977

Effects of altitude on myoglobin and mitochondrial protein in canine skeletal muscle.

Myoglobin and mitochondrial protein contents were measured spectrophotometrically in the sternothyroid muscle of 8 dogs, first in Dnver, at a PB of 635 mm Hg, and after a 3-week exposure to a PB of 435 mm Hg, using a hypobaric chamber. The PaO2 at a PB of 635 mm Hg was 81.9 mm Hg and at a PB of 435 mm Hg, it was 54.6 mm Hg. Myoglobin concentration increased from 3.67 +/- 1.07 to 5.47 +/- 0.90 mg/g fresh muscle while mitochondrial protein content increased from 3.04 +/- 0.80 to 4.96 +/- 2.59 mg N2/g fresh muscle upon exposure to simulated altitude. It is believed that these changes in the biochemistry of the muscle are related to alterations in muscle fiber type composition, which seem to be adaptive in nature.

Acclimatization↗
PubMed1976

Effects of simulated altitude on O2 transport in dogs.

The effects of exposure to simulated altitude on skeletal muscle and on the cardiocirculatory system rhave been studied on awake, conscious, dogs (16-39 kg) at rest and during moderate treadmill exercise at 15% incline. Measurements were obtained in Denver at a PB of 635 mm Hg and after 3 weeks of continuous exposure to a PB of 435 mm Hg using a hypobaric chamber. At both levels of PB the dogs showed marked panting, associated with pulmonary hyperventilation and low PaCO2's (28 mm Hg at 635 and 17 mm Hg at 435 mm Hg). Resting VO2's were high (12.4 and 11.4 ml/min-kg) reflecting the high respiratory outputs. [Hb] and Hct increased significantly after 3 weeks at 435 mm Hg with a 4 mm Hg decrease in P50. Q, HR, SV and systemic blood pressures were normal in both normoxic and hypoxic animals, at rest as well as during exercise. Arterial and mixed venous PO2's decreased in the hypoxic dogs (82 to 56 and 42 to 36 mm Hg, respectively) but arterial O2 content, arterial-venous O2 content difference and systemic O2 transport remained unchanged. Capillary density in the sternothyroid muscle doubled (617 to 1245 cap/mm2) after 3 weeks at a PB of 435, whereas the average muscle fiber diameter decreased about 30%. Calculations indicate that the PO2 in the 'lethal corner' of the muscle fiber is relatively higher in the hypoxic animal because of the decrease in fiber size and intercapillary distances.

Altitude↗
PubMed1976

Capillary density of skeletal muscle in Andean dogs.

High capillary density and small muscle fiber diameters were found in the sternothyroid muscle of dogs native to 4350 m. The number of capillaries per square millimeter was three times greater while the diameter was less than half of those obtained in the same muscle of normoxic dogs. These findings suggest that tissular adaptative mechanisms are important in the process of acclimatization to hypoxia, contributing to the maintenance of adequate levels of PO2 in the tissue in the presence of hypoxemia.

Adaptation, Physiological↗
PubMed1975

Mechanisms of O2 transport in Andean dogs.

Using previously inserted catheters, 11 dogs native to high altitude (7.5-23 kg bwt) were studied standing and unsedated in Cerro de Pasco, Peru at 4350 meters. Hemoglobin (Hb), hematocrit (Hct), O2 and CO2 contents, PO2, PCO2 and pH were measured in simultaneously obtained arterial and mixed venous blood samples. Blood pressures were measured in the pulmonary artery and the left ventricle and cardiac output (Q) was determined by dye dilution. Moderately higher values for Hb and Hct were found in these dogs. Hb-O2 affinity was no different than that found in sea level dogs: the P50 in the Andean dogs was 31.6 mm Hg at 38 degrees C and pH of 7.4. Because of the low barometric pressure at 4350 m (458 mmHg) the partial pressures of oxygen in inspired and in alveolar air were lower than at sea level: 84.3 and 56.4 mm Hg, respectively. PAO2 and PVO2, were 55.5 and 32.9 mm Hg while the SAO2 and SVO2 were 79.5 and 50.7%, respectively. Marked hyperventilation was observed (PACO2, 25.6 mm Hg) however, pH was normal. Cardiac output was normal (average 162 plus or minus 39 ml/min/kg). Moderate pulmonary arterial hypertension was observed in the presence of normal left ventricular end diastolic pressure suggesting increased pulmonary vascular resistance.

Acclimatization↗