Faculty Collaboration Database

Ventilatory phenotypes among four strains of adult rats. J Appl Physiol (1985) 2002 Sep;93(3):974-83

Date

08/17/2002

Pubmed ID

12183493

DOI

10.1152/japplphysiol.00019.2002

Scopus ID

2-s2.0-0036707832 (requires institutional sign-in at Scopus site)   54 Citations

Abstract

Our purpose in this study was to identify different ventilatory phenotypes among four different strains of rats. We examined 114 rats from three in-house, inbred strains and one outbred strain: Brown Norway (BN; n = 26), Dahl salt-sensitive (n = 24), Fawn-hooded Hypertensive (FHH: n = 27), and outbred Sprague-Dawley rats (SD; n = 37). We measured eupneic (room air) breathing and the ventilatory responses to hypoxia (12% O(2)-88% N(2)), hypercapnia (7% CO(2)), and two levels of submaximal exercise. Primary strain differences were between BN and the other strains. BN rats had a relatively attenuated ventilatory response to CO(2) (P < 0.001), an accentuated ventilatory response to exercise (P < 0.05), and an accentuated ventilatory roll-off during hypoxia (P < 0.05). Ventilation during hypoxia was lower than other strains, but hyperventilation during hypoxia was equal to the other strains (P > 0.05), indicating that the metabolic rate during hypoxia decreased more in BN rats than in other strains. Another strain difference was in the frequency and timing components of augmented breaths, where FHH rats frequently differed from the other strains, and the BN rats had the longest expiratory time of the augmented breaths (probably secondary to the blunted CO(2) sensitivity). These strain differences not only provide insight into physiological mechanisms but also indicate traits (such as CO(2) sensitivity) that are genetically regulated. Finally, the data establish a foundation for physiological genomic studies aimed at elucidating the genetics of these ventilatory control mechanisms.

Author List

Hodges MR, Forster HV, Papanek PE, Dwinell MR, Hogan GE

Authors

Melinda R. Dwinell PhD Professor in the Physiology department at Medical College of Wisconsin
Matthew R. Hodges PhD Professor in the Physiology department at Medical College of Wisconsin
Paula Papanek PhD, MPT, LAT, FACSM Associate Professor & Director of Exercise Science in the Exercise Science & Physical Therapy department at Marquette University

MESH terms used to index this publication - Major topics in bold

Animals
Female
Hypercapnia
Hypoxia
Male
Motor Activity
Phenotype
Rats
Rats, Inbred Strains
Respiration
Respiratory Physiological Phenomena
Sex Characteristics
Species Specificity