Whole body and muscle respiratory capacity with dobutamine and hindlimb suspension.
J Appl Physiol (1985)
; 71(6): 2419-24, 1991 Dec.
Article
in En
| MEDLINE
| ID: mdl-1778941
ABSTRACT
The effects of repeated injections of dobutamine, a synthetic catecholamine, were studied in control and tail-suspended rats to determine whether this drug could improve the metabolic response to unweighting. Dobutamine prevented the decrease in maximal oxygen uptake (VO2max) induced by hindlimb suspension. Furthermore, VO2max was 12% greater in dobutamine-treated animals than in saline-treated control animals. Soleus muscle weight and mean fiber cross-sectional area were decreased by 60 and 75%, respectively, in saline- and dobutamine-treated suspended rats. Total capillary length was unaffected by unweighting and increased 21% in all animals receiving dobutamine. The drug prevented the increase in total mitochondrial volume density (+30%) induced by unweighting but did not change total mitochondrial volume. Our results suggest that 1) dobutamine is useful to prevent the decrease of total aerobic capacity during hindlimb suspension, 2) dobutamine increases VO2max in control rats, and 3) total capillary length in soleus muscle is increased by the drug in all groups, although no beneficial effects on mitochondria can be detected.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oxygen Consumption
/
Weightlessness
/
Dobutamine
/
Muscles
Type of study:
Etiology_studies
Limits:
Animals
Language:
En
Journal:
J Appl Physiol (1985)
Journal subject:
FISIOLOGIA
Year:
1991
Type:
Article
Affiliation country:
France