Genetic components of variations of red cell glycolytic intermediates at two altitudes among the South American Aymara.

Red cell haemoglobin (Hb), haematocrit (Ht), 2,3-diphosphoglycerate (DPG), and adenosine triphosphate (ATP) levels were measured in 876 individuals from six villages at two altitude levels (altiplano and coast) of the Departmento de Arica of Northern Chile. Of these, data on 761 individuals are subjected to analysis to search for the evidence of genetic adaptation to a hypoxic environment at a high altitude. Total phenotypic variance for each of the variables is higher at the altiplano as compared to their counterparts at the coastal level.

Effect of chronic altitude hypoxia on hematologic and glycolytic parameters.

The physiological effect of chronic exposure to altitude hypoxia on the glycolytic intermediates, adenosine triphosphate and 2,3-diphosphoglyceric acid, and the hematologic parameters, hemoglobin, hematocrit, and mean cell hemoglobin concentration, has been examined in an indigenous population, the Aymara, of the Departamento de Arica, Chile. This population normally resides at three altitudes: the coast (0-500 m), the sierra (2,500-3,500 m), and the altiplano (above 4,200 m). After isolation of altitude from other environmental factors (age, sex, body build, ethnicity, smoking, and residential permanence), an increase in 2,3-diphosphoglycerate and a decrease in adenosine triphosphate was observed.

Circadian heart rate rhythmicity: comparison between an Eskimo and other population groups.

This brief communication reports the results of 24-ambulatory cardiac monitoring of a Bering Strait Eskimo population and compares the findings with 3 other populations. Similar heart rate rhythmicity and almost identical acrophases are found in the Eskimo, Aymara Indian and French populations. However, the Alaskan Eskimo and Aymara Indian 24-h means vary by approximately 15 beats/min, with the American population between these two.

Circadian changes in the bioavailability and effects of indomethacin in healthy subjects.

Nine subjects, 19 to 29 years old (2 females) synchronized with activity from 07.00 to 00.00 received a single daily oral dose (100 mg) of indomethacin at fixed hours: 07.

2,3-Diphosphoglycerate and night vision.

Recovery of night vision at altitude has been examined in relationship to changes of 2,3,diphosphoglycerate (DPG). It appears that, if DPG influences night adaptation, its effect is small. Inter-individual variability is large, both in terms of DPG and performance on the MESOP, the device used to measure dark adaptation.

[Circadian rhythms in the urinary excretion of salicylate (chronopharmacokinetics) in healthy adults].

Six healthy adults volunteered to ingest a 1 g solution/24 h of sodium salicylate in a study consisting of 4 standardized tests. The difference between tests was the timing of drug absorption: 07(00), 11(00), 19(00) and 23(00) respectively. The 4 separate tests were performed at least 1 week apart.

[Circadian variations of the effects of ethanol and of blood ethanol values in the healthy adult man. Chronopharmacological study].

Six healthy young men (22 to 26 years) who had fasted for 12 hours volunteered for this study (subject synchronization: diurnal activity from 07(00) to midnight and nocturnal rest). A set dose of ethanol (0.67 g/kg body weight) was ingested at the fixed (and random) hours of 07(00), 11(00), 19(00) and 23(00), with a week between tests.