EFFECTS OF ESTROGEN ON SERUM ALKALINE PHOSPHATASE ACTIVITY OF MINIATURE SWINE

Abstract

Changes in serum alkaline phosphatase (ALP) in Göttingen miniature pigs given 5mg/kg/day of ethynylestradiol (EE) for 10 consecutive days were examined and the organ from which these changes originated was investigated.
Serum ALP activity did not show any appreciable changes in the non-treated group, but decreased in the EE-treated group with a significant difference seen since the 3rd day.
Concentration of calcium in serum showed no appreciable change in the non-treated group, whereas, in the EE-treated group, it decreased in the same manner as the ALP activity, with a significant difference seen from the 3rd day.
Concentration of inorganic phosphorus in serum showed the maximum value on the 3rd day in the non-treated group and the minimum value on the 3rd day in the EE-treated group with a significant difference seen between the two groups, but there was no consistent tendency observed as against the ALP activity or calcium concentration.
Organ ALP activity tended to rise in the liver, kidneys and small intestine because of EE administration, but there was no significant difference. However, in the bones, there was a remarkable decrease in activity.
In the liver histology, there were no findings of bile congestion by EE administration, expantion of the bile duct lumen, appearance of round cells in the vicinity of the bile duct or infiltration of polymorphonuclear leukocytes.
As stated above, it was found out that the administration of EE caused changes in the bones such as inhibited production of ALP in bone and reduced transfer of ALP of bone origin into serum, which resulted in a reduced activity of ALP in serum.