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An in vivo study of the effects of ischaemia on uterine contraction, intracellular pH and metabolites in the rat.
- Source :
-
The Journal of physiology [J Physiol] 1994 Apr 15; Vol. 476 (2), pp. 349-54. - Publication Year :
- 1994
-
Abstract
- There are no data concerning the functional or metabolic effects of hypoxia in vivo in smooth muscle. We have therefore used 31P-NMR spectroscopy and intra-uterine pressure measurements to examine simultaneously, in vivo, the effect of ischaemia on uterine metabolites, intracellular pH (pHi) and force. A 1-2 cm portion of uterus from day 1 postpartum anaesthetized rats was exteriorized and an NMR surface coil placed on it. A balloon catheter in the uterine lumen recorded intra-uterine pressure changes from the same area. Reversible occluders were placed around the uterine artery. Occlusion produced a decrease and then abolition of contractions, within 10 min. In four of five animals contraction was abolished within 2 min. Upon reperfusion force was rapidly restored (1 min), in all preparations. The mean level of force was significantly above control (pre-occlusion) 20-30 min after reperfusion. The NMR data showed a significant fall in [ATP] (28%) and [phosphocreatine] (34%) during occlusion. Inorganic phosphate doubled in concentration during this period. Metabolites recovered slowly upon reperfusion, taking 20-30 min to return to pre-occlusion levels. The mean pHi fell from 7.32 to 7.00 upon occlusion and was rapidly reversed upon reperfusion. The changes in pHi closely correlated with the changes in uterine force. Decreases of pHi of a similar magnitude in vitro have previously been shown to abolish contractions; thus it is suggested that during ischaemia in vivo the depression of contraction is caused by the large fall in pHi.
- Subjects :
- Animals
Female
Hydrogen-Ion Concentration
Hypoxia physiopathology
In Vitro Techniques
Magnetic Resonance Spectroscopy
Muscle, Smooth blood supply
Muscle, Smooth metabolism
Phosphates metabolism
Phosphocreatine metabolism
Rats
Rats, Wistar
Regional Blood Flow physiology
Uterus physiology
Ischemia physiopathology
Muscle, Smooth physiology
Uterine Contraction physiology
Uterus blood supply
Subjects
Details
- Language :
- English
- ISSN :
- 0022-3751
- Volume :
- 476
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- The Journal of physiology
- Publication Type :
- Academic Journal
- Accession number :
- 8046648
- Full Text :
- https://doi.org/10.1113/jphysiol.1994.sp020136