REFRACTORINESS OF BOTH UTERUS AND MAMMARY-GLAND OF THE COW TO PROSTAGLANDIN-F2-ALPHA ADMINISTRATION - CLINICAL IMPLICATION

  • 1 January 1981
    • journal article
    • research article
    • Vol. 42  (2) , 314-317
Abstract
Uterine and mammary pressure changes were simultaneously measured in lactating nonpregnant cows injected (i.v.) with different doses (0.1 to 32.0 mg) of prostaglandin[PG]F2.alpha.. The total work of the uterus increased up to 250% of baseline value as the dose of PGF2.alpha. was increased. A dose-response relationship was not seen in the uterus. Partial refractoriness was developed in the uterus, and total refractoriness was developed in the mammary gland. Further challenge with oxytocin (30 U) elicited significant responses in both the uterus and the mammary gland. Because of the development of refractoriness and side effects, PGF2.alpha. is not recommended as a drug to be used when mechanical evacuation (free of endocrine effect) of the uterus or mammary gland (or both) is indicated.