Biomedical subjects

David R Woods

Publications and source records attributed to David R Woods.

4 recordsLinked to original sources

PubMed2003

Skeletal muscle RAS and exercise performance.

A local renin-angiotensin system (RAS) may be suggested by evidence of gene expression of RAS components within the tissue as well as physiological responsiveness of this gene expression. This review will focus on the evidence supporting the existence of the constituent elements of a physiologically functional paracrine muscle RAS. The effect of local skeletal muscle RAS on human exercise performance will be explored via its relation with pharmacological intervention and genetic studies. The most likely configuration of the muscle RAS is a combination of in situ synthesis and uptake from the circulation of RAS components. A reduction in angiotensin-converting enzyme (ACE) activity reverses the decline in physical performance due to peripheral muscle factors in those with congestive heart failure and may halt or slow decline in muscle strength in elderly women. Genetic studies suggest that increased ACE and angiotensin II (Ang II) mediate greater strength gains perhaps via muscle hypertrophy whereas lower ACE levels and reduced bradykinin (BK) degradation mediate enhanced endurance performance perhaps via changes in substrate availability, muscle fibre type and efficiency.

Angiotensin II↗

PubMed2002

Insertion/deletion polymorphism of the angiotensin I-converting enzyme gene and arterial oxygen saturation at high altitude.

There is a significant genetic influence on arterial oxygen saturation (Sa(O(2))) in high-altitude (HA) residents. It is not known whether this is true of lowlanders ascending to HA. The I allele of the angiotensin-converting enzyme (ACE) gene is associated with low ACE activity and elite endurance performance. An excess of the I allele has also been reported in South American natives living over 3,000 m and among elite HA mountaineers who demonstrate extreme endurance in a hypoxic environment, where maintenance of Sa(O(2)) is crucial to performance. We postulated that the I allele may confer an advantage at HA through genotype-dependent alterations in Sa(O(2)). Rapid ascent (n = 32) and slow ascent groups (n = 40), ascending to approximately 5,000 m over 12.0 and 18.5 days, respectively, had their Sa(O(2)) assessed throughout and compared with their ACE genotype. Resting Sa(O(2)) was independent of the ACE genotype and remained so for the slow ascent group, in whom the fall in Sa(O(2)) with ascent was genotype independent. However, Sa(O(2)) with ascent was significantly associated with the ACE genotype in the rapid ascent group (p = 0.01) with a relatively sustained Sa(O(2)) in the II subjects. These data are the first to report an association of the I allele with the maintenance of Sa(O(2)) at HA.

Adult↗

PubMed2002

Human performance: a role for the ACE genotype?

The I allele of the angiotensin I-converting enzyme (ACE) gene is associated with lower ACE activity and endurance performance; an excess occurs in elite distance runners, rowers, and mountaineers, perhaps secondary to enhanced muscle efficiency. Conversely, the D allele is associated with training-related strength gain and elite power-oriented performance secondary to increased ACE and angiotensin II, a growth factor.

Alleles↗

PubMed1988

Cloning and Expression of a Clostridium acetobutylicum Alcohol Dehydrogenase Gene in Escherichia coli.

An alcohol dehydrogenase (ADH) gene from Clostridium acetobutylicum was cloned on a recombinant plasmid, pCADH100. Escherichia coli HB101, and an allyl alcohol-resistant mutant, HB101-adh1, containing this plasmid were unable to grow aerobically or anaerobically on agar media containing sublethal concentrations of allyl alcohol. E. coli HB101 and HB101-adh1 transformed with the plasmid pCADH100 produced increased levels of ethanol when grown anaerobically under alkaline conditions in the absence of nitrate. Cell extracts from aerobically and anaerobically grown E. coli HB101(pCADH100) and HB101-adhl(pCADH100) cells exhibited increased levels of NADP-dependent ADH activity with either ethanol or butanol as the substrate. The inability of E. coli HB101(pCADH100) to grow in the presence of allyl alcohol correlated with the appearance of an NADP-dependent ADH activity band on nondenaturing polyacrylamide gel electrophoresis with either ethanol or butanol as the substrate. The position of the cloned NADP-dependent ADH activity bands in E. coli HB101(pCADH100) cell extracts with either ethanol or butanol as the substrate coincided with the position of a single NADP-dependent ADH activity band in extracts of C. acetobutylicum cells. E. coli HB101(pCADH100) cell extracts prepared from both aerobically and anaerobically grown cells exhibited an additional protein band with an apparent M(r) of approximately 33,000 on sodium dodecyl sulfate-polyacryl-amide gel electrophoresis which was absent in cell extracts of E. coli HB101. A protein band with a similar apparent M(r) was observed in cell extracts of C. acetobutylicum, and in vitro transcription and translation experiments with pCADH100 produced a major protein product with a similar apparent M(r).

Journal Article↗