Effect of prostaglandins F2alpha and E2 on milk ejection, blood pressure and blood flow through the mammary artery in the cow.
The influence of prostaglandins (PG) F2alpha and E2 on milk ejection, mammary artery blood flow and arterial blood pressure was studied in lactating cows. Injections of both PG in the jugular vein or the carotid artery induced milk ejection after a relatively long latency period. The minimal effective dose amounted to 1 to 5 microng and to 100 to 300 microng for PGF2alpha and PGE2 respectively. In several cases with PGF2alpha and once with PGE2 milk ejection was accompanied with a simultaneous increase in blood flow through the mammary artery whereas arterial blood pressure remained unchanged. Both routes of administration showed the same response. It was suggested that the effect of the PG on the bovine myoepithelium is indirect, possibly secondary to a release of oxytocin from the neurohypophysis.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002417:Cattle; D005260:Female; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D007774:Lactation / Q000187:drug effects*; D008323:Mammary Arteries; D008893:Milk Ejection / Q000187:drug effects*; D011247:Pregnancy; D011458:Prostaglandins E / Q000008:administration & dosage / Q000494:pharmacology*; D011460:Prostaglandins F / Q000008:administration & dosage / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects*; D013895:Thoracic Arteries; D013997:Time Factors
D011458:Prostaglandins E; D011460:Prostaglandins F