| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Research and Development, John D. Dingell VA Medical Center, Detroit, Michigan, United States
2 Research and Development, John D. Dingell VA Medical Center, Detroit, Michigan, United States; Physiology, Wayne State University, Detroit, Michigan, United States; Internal Medicine, Wayne State University, Detroit, Michigan, United States
3 Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, United States
4 Research and Development, John D. Dingell VA Medical Center, Detroit, Michigan, United States; Internal Medicine, Wayne State University, Detroit, Michigan, United States; Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, United States; Biomedical Engineering, Wayne State University, Detroit, Michigan, United States
* To whom correspondence should be addressed. E-mail: jmateika{at}med.wayne.edu.
We hypothesized that the ventilatory threshold and sensitivity to carbon dioxide in the presence of hypoxia and hyperoxia during wakefulness would be increased following testosterone administration in pre-menopausal women. Additionally, we hypothesized that the sensitivity to carbon dioxide increases following episodic hypoxia and that this increase is enhanced after testosterone administration. Eleven females completed 4 modified carbon dioxide rebreathing trials before and after episodic hypoxia. Two rebreathing trials before and after episodic hypoxia were completed with oxygen levels sustained at 150 mmHg, the remaining trials were repeated while oxygen was maintained at 50 mmHg. The protocol was completed following 8-10 days of treatment with testosterone or placebo skin patches. Resting minute ventilation was greater following treatment with testosterone compared to placebo (testosterone - 11.38 ± 0.43 vs. placebo - 10.07 ± 0.36 L/min; p < 0.01). This increase was accompanied by an increase in the ventilatory sensitivity to carbon dioxide in the presence of sustained hyperoxia (VSCO2hyperoxia) compared to placebo (3.6 ± 0.5 vs. 2.9 ± 0.3; p < 0.03). No change in the ventilatory sensitivity to carbon dioxide in the presence of sustained hypoxia (VSCO2hypoxia) following treatment with testosterone was observed. However, the VSCO2hypoxia was increased after episodic hypoxia. This increase was similar following treatment with placebo or testosterone patches. We conclude that treatment with testosterone leads to increases in the VSCO2hyperoxia, indicative of increased central chemoreflex responsiveness. We also conclude that exposure to episodic hypoxia enhances the VSCO2hypoxia, but that this enhancement is unaffected by treatment with testosterone.
This article has been cited by other articles:
|
|
 |
|
  J. H. Mateika and G. Narwani Intermittent hypoxia and respiratory plasticity in humans and other animals: does exposure to intermittent hypoxia promote or mitigate sleep apnoea? Exp Physiol, March 1, 2009; 94(3): 279 - 296. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. P. Fawcett, Y. Aracava, M. Adler, E. F. R. Pereira, and E. X. Albuquerque Acute Toxicity of Organophosphorus Compounds in Guinea Pigs Is Sex- and Age-Dependent and Cannot Be Solely Accounted for by Acetylcholinesterase Inhibition J. Pharmacol. Exp. Ther., February 1, 2009; 328(2): 516 - 524. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
