TY - JOUR
T1 - Effect of hyperpnea on the cholesterol to disaturated phospholipid ratio in alveolar surfactant of rats
AU - Orgeig, Sandra
AU - Barr, Heather A.
AU - Nicholas, Terence E.
PY - 1995
Y1 - 1995
N2 - Hyperpnea induced by swimming rats for 30 min decreased the choksterol/disaturated phospholipid ratio (CHOL/DSP) in the tubular myelin-poor fraction (alv-2), but did not affect the tubular myelin-rich fraction (alv-1). The phenomenon was further illustrated by the marked inverse relationship between CHOLIDSP and DSP. Because such a result could reflect differential release, processing, or reuptake within the alveolar compartment, this study further explored the mechanism in the rat isolated perfused lung (IPL), using radiolabeled CHOL (3H) and DSP (14C). The study also examined whether the decrease in CHOLIDSP with swimming was associated with the increase in either tidal volume (VT), frequency of breathing (f), or both. It was found that whereas a 2.5-fold increase in VTfor 15 min in the IPL increased the CHOL/DSP in alv-1 and decreased it in alv-2, a 3-fold increase in f markedly increased the CHOLIDSP in both alveolar subtractions. In apparent contrast, the increases in both VT and f markedly depressed the ratio of the sp act of CHOLIDSP, reflecting a large decrease in the sp act of CHOL in the alveolar compartment. In view of the acute nature of these IPL experiments, it is suggested that the changes reflect the differential release of CHOL and DSP. Furthermore, the marked decrease in sp act of CHOL must reflect a second source of CHOL supplying the alveolar compartment with sterol of low sp act. It is concluded that there is differential handling of surfactant CHOL and DSP in the alveolar compartment of the rat and that the decrease in CHOL/DSP with swimming is due to an increase in VT.
AB - Hyperpnea induced by swimming rats for 30 min decreased the choksterol/disaturated phospholipid ratio (CHOL/DSP) in the tubular myelin-poor fraction (alv-2), but did not affect the tubular myelin-rich fraction (alv-1). The phenomenon was further illustrated by the marked inverse relationship between CHOLIDSP and DSP. Because such a result could reflect differential release, processing, or reuptake within the alveolar compartment, this study further explored the mechanism in the rat isolated perfused lung (IPL), using radiolabeled CHOL (3H) and DSP (14C). The study also examined whether the decrease in CHOLIDSP with swimming was associated with the increase in either tidal volume (VT), frequency of breathing (f), or both. It was found that whereas a 2.5-fold increase in VTfor 15 min in the IPL increased the CHOL/DSP in alv-1 and decreased it in alv-2, a 3-fold increase in f markedly increased the CHOLIDSP in both alveolar subtractions. In apparent contrast, the increases in both VT and f markedly depressed the ratio of the sp act of CHOLIDSP, reflecting a large decrease in the sp act of CHOL in the alveolar compartment. In view of the acute nature of these IPL experiments, it is suggested that the changes reflect the differential release of CHOL and DSP. Furthermore, the marked decrease in sp act of CHOL must reflect a second source of CHOL supplying the alveolar compartment with sterol of low sp act. It is concluded that there is differential handling of surfactant CHOL and DSP in the alveolar compartment of the rat and that the decrease in CHOL/DSP with swimming is due to an increase in VT.
KW - Cholesterol
KW - Disaturated phospholipids
KW - Exercise
KW - Frequency of breathing
KW - Hyperpnea
KW - Surfactant
KW - Tidal volume
UR - http://www.scopus.com/inward/record.url?scp=0028898524&partnerID=8YFLogxK
U2 - 10.3109/01902149509031751
DO - 10.3109/01902149509031751
M3 - Article
C2 - 7729374
AN - SCOPUS:0028898524
VL - 21
SP - 157
EP - 174
JO - Experimental Lung Research
JF - Experimental Lung Research
SN - 0190-2148
IS - 1
ER -