Selected contribution: chronic intermittent hypoxia enhances respiratory long-term facilitation in geriatric female rats
- PMID: 12937027
- DOI: 10.1152/japplphysiol.00476.2003
Selected contribution: chronic intermittent hypoxia enhances respiratory long-term facilitation in geriatric female rats
Abstract
Age and the estrus cycle affect time-dependent respiratory responses to episodic hypoxia in female rats. Respiratory long-term facilitation (LTF) is enhanced in middle-aged vs. young female rats (72). We tested the hypothesis that phrenic and hypoglossal (XII) LTF are diminished in acyclic geriatric rats when fluctuating sex hormone levels no longer establish conditions that enhance LTF. Chronic intermittent hypoxia (CIH) enhances LTF (41); thus we further predicted that CIH would restore LTF in geriatric female rats. LTF was measured in young (3-4 mo) and geriatric (20-22 mo) female Sasco Sprague-Dawley rats and in a group of geriatric rats exposed to 1 wk of nocturnal CIH (11 vs. 21% O2 at 5-min intervals, 12 h/night). In anesthetized, paralyzed, vagotomized, and ventilated rats, time-dependent hypoxic phrenic and XII responses were assessed. The short-term hypoxic response was measured during the first of three 5-min episodes of isocapnic hypoxia (arterial Po2 35-45 Torr). LTF was assessed 15, 30, and 60 min postepisodic hypoxia. Phrenic and XII short-term hypoxic response was not different among groups, regardless of CIH treatment (P > 0.05). LTF in geriatric female rats was smaller than previously reported for middle-aged rats but comparable to that in young female rats. CIH augmented phrenic and XII LTF to levels similar to those of middle-aged female rats without CIH (P < 0.05). The magnitude of phrenic and XII LTF in all groups was inversely related to the ratio of progesterone to estradiol serum levels (P < 0.05). Thus CIH and sex hormones influence the magnitude of LTF in geriatric female rats.
Similar articles
-
Similarities and differences in mechanisms of phrenic and hypoglossal motor facilitation.Respir Physiol Neurobiol. 2011 Oct 15;179(1):48-56. doi: 10.1016/j.resp.2011.06.022. Epub 2011 Jul 2. Respir Physiol Neurobiol. 2011. PMID: 21745601 Free PMC article. Review.
-
Selected contribution: Time-dependent hypoxic respiratory responses in female rats are influenced by age and by the estrus cycle.J Appl Physiol (1985). 2001 Dec;91(6):2831-8. doi: 10.1152/jappl.2001.91.6.2831. J Appl Physiol (1985). 2001. PMID: 11717252
-
Ageing and gonadectomy have similar effects on hypoglossal long-term facilitation in male Fischer rats.J Physiol. 2005 Mar 1;563(Pt 2):557-68. doi: 10.1113/jphysiol.2004.077511. Epub 2004 Dec 21. J Physiol. 2005. PMID: 15613371 Free PMC article.
-
Early postnatal chronic intermittent hypoxia modifies hypoxic respiratory responses and long-term phrenic facilitation in adult rats.Am J Physiol Regul Integr Comp Physiol. 2006 Jun;290(6):R1664-71. doi: 10.1152/ajpregu.00851.2005. Epub 2006 Feb 2. Am J Physiol Regul Integr Comp Physiol. 2006. PMID: 16455761
-
Long term facilitation of phrenic motor output.Respir Physiol. 2000 Jul;121(2-3):135-46. doi: 10.1016/s0034-5687(00)00124-9. Respir Physiol. 2000. PMID: 10963770 Review.
Cited by
-
Glossopharyngeal long-term facilitation requires serotonin 5-HT2 and NMDA receptors in rats.Respir Physiol Neurobiol. 2010 Feb 28;170(2):164-72. doi: 10.1016/j.resp.2009.12.005. Epub 2009 Dec 21. Respir Physiol Neurobiol. 2010. PMID: 20026287 Free PMC article.
-
Similarities and differences in mechanisms of phrenic and hypoglossal motor facilitation.Respir Physiol Neurobiol. 2011 Oct 15;179(1):48-56. doi: 10.1016/j.resp.2011.06.022. Epub 2011 Jul 2. Respir Physiol Neurobiol. 2011. PMID: 21745601 Free PMC article. Review.
-
Diaphragm long-term facilitation following acute intermittent hypoxia during wakefulness and sleep.J Appl Physiol (1985). 2011 May;110(5):1299-310. doi: 10.1152/japplphysiol.00055.2011. Epub 2011 Mar 3. J Appl Physiol (1985). 2011. PMID: 21372099 Free PMC article.
-
Increased spinal adenosine impairs phrenic long-term facilitation in aging rats.J Appl Physiol (1985). 2023 Jun 1;134(6):1537-1548. doi: 10.1152/japplphysiol.00197.2023. Epub 2023 May 11. J Appl Physiol (1985). 2023. PMID: 37167263 Free PMC article.
-
Conversion from testosterone to oestradiol is required to modulate respiratory long-term facilitation in male rats.J Physiol. 2006 Nov 1;576(Pt 3):903-12. doi: 10.1113/jphysiol.2006.114850. Epub 2006 Aug 24. J Physiol. 2006. PMID: 16931552 Free PMC article.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Medical
Miscellaneous
