The Effects Of VFA And Na-VFA,Estradiol, Progesterone, PH On Abomasums Smooth Muscle Contraction In Vitro

Atony of abomasum is a main reason for abomasul displacement.Currently,the study about the constriction of the smooth muscle of abomasum has not been carried out athome and abroad. In this experiment, by observing how smooth muscles of abomasum in vitro effected by volatile fatty acid (VFA) and Na-VFA, pH, estrogen,we aim to research the impact of the internal environment on the constriction of the abomasum,in order to better reveal the mechanism of the abomasul atony and provide a theoretical basis to the prevention of abomasul displacement in production.Before sampling, the healthy goats selected have to be forbidden from food for 24 hours and water for 4 hours ,then the smooth muscle sample of abomasum could be obtained by surgery.The samples, 1.0cm in length, 0,2cm in wide, were conserved in the 38.0±0.5℃Tyrodo .With one end being fixed to the water bath by a hook,the other end of the muscle sample was connected by silk thread.The Medlab biological signal acquisition system was used to observe the constraction of smooth muscles of abomasum effected by some test drugs.In the experiment,we have got that glacial acetic acid with the concentration of 1.6~3.2mmol/L and 3~8mmol/L could evidently restrain the contraction of the smooth muscles(P<0.01), while with the concentration of 8~33mmol/L,it could enhance the contraction strength(P<0.05), and the change was not evident with the concentration of 30~70mmol/L(P>0.05).Otherwise,propionic acid with the concentration of 1.0~1.8mmol/L and 10~18mmol/L, and butyric acid with the concentration of 5~13mmol/L could restrain the contraction of the smooth muscles(P<0.01); propionic acid with the concentration of 0.05~0.13mmol/L, and butyric acid with the concentration of 0.25~0.65mmol/L and 0.7~1.4mmol/L didn't affect the smooth muscles too much(P>0.05).Sodium acetate, sodium propionate and sodium butyrate respectively with the final concentration of 0.5~3.5mmol/L, 0.05~0.35mmol/L and 0.25~1.75mmol/L didn't process too much influence on the smooth muscles(P>0.05). Progesterone with the concentration of 0.4~12.8 ng/mL could reduce the contraction strength(P<0.01), while estradiol with the final concentration of 50 pg/mL~101.2 ng/mL could reduce the contraction strength(P<0.01). Heigher with the pH , the contraction strength inhibitioned evidently(P<0.01).