Uterine contractility is strongly influenced by steroids and glucose metabolism: an in vitro study on bovine myometrium.
BACKGROUND
Energetic substrates and hormonal phase are important for uterine contractions. Etomoxir a muscle carnitine palmitoyltransferase-1 inhibitor, able to diverge uterine metabolic pathways towards glycolysis, facilitates glucose utilisation. The aim of this study was to evaluate its effect on uterine contractility in different hormonal situations.


METHODS
Uterine samples were collected from 60 cows during follicular phase, luteal phase and pregnancy. The cows were slaughtered at a local abattoir. Longitudinal strips were mounted vertically in a 30-ml organ bath connected to an isometric force transducer. Contractions were recorded with an ink-writing polygraph. After the equilibration period, etomoxir was added to the organ bath at different concentrations. The amplitude and frequency of contractions were registered before and after addition of etomoxir.


RESULTS
In 17 strips from pregnant cows, etomoxir increased the amplitude (p < 0.05) of contractions but not the frequency in comparison with basal conditions. In 15 strips from cows in the luteal phase, etomoxir increased the amplitude (p < 0.05) and frequency of contractions (p < 0.05 at 5 μM and p < 0.01 at 8 and 10 μM). In 18 strips from cows in the follicular phase, etomoxir increased the frequency of contractions but not the amplitude (p < 0.01 at 5 μM and p < 0.05 at 8 and 10 μM).


CONCLUSIONS
This study confirms the importance of glucose for uterine contractility and, moreover, it underlines different patterns of contraction with regard to the hormonal status.
Rizzo
Annalisa
A
Department of Animal Production, Faculty of Veterinary Medicine, University of Bari, Bari, Italy.
Angioni
Stefano
S
Spedicato
Massimo
M
Minoia
Giuseppe
G
Mutinati
Maddalena
M
Trisolini
Carmelinda
C
Sciorsci
Raffaele Luigi
RL
D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000037:antagonists & inhibitors*; D002417:Cattle; D004852:Epoxy Compounds / Q000494:pharmacology*; D005260:Female; D005498:Follicular Phase; D005947:Glucose / Q000378:metabolism*; D066298:In Vitro Techniques; D008183:Luteal Phase; D011247:Pregnancy; D014590:Uterine Contraction / Q000187:drug effects*
D004852:Epoxy Compounds; D002334:Carnitine O-Palmitoyltransferase; D005947:Glucose; C054207:etomoxir