Prostaglandin E-2 as a potential luteotrophic agent during early pregnancy in cattle.
Heifers slaughtered on Day 18/19 of pregnancy had significantly higher (P less than 0.001) concentrations of PGE-2 (measured as its methyl oxime) in uterine flushings than did animals slaughtered on Days 6 or 12 of pregnancy, or on Days 6 or 12 of the oestrous cycle. In addition, concentrations were higher in the uterine horn ipsilateral to the corpus lueum on Days 12 (P less than 0.05) and 18/19 (P less than 0.01) than in the contralateral horn. Incubation of dispersed luteal cells for 3 h with LH (0.1 or 100 ng/ml) and/or PGE-2 (0.01-1000 ng/ml) in vitro showed no differences in basal progesterone production or in the responses to exogenous hormones between pregnant and non-pregnant cattle. However, low doses of PGE-2 (0.01-10 ng/ml) inhibited the stimulation of progesterone secretion by the lower dose of LH. These findings indicate that although PGE-2 can stimulate progesterone synthesis by luteal cells it may also have inhibitory effects, and therefore its role in pregnancy requires further definition.
Shelton
K
K
AFRC Research Group on Hormones and Farm Animal Reproduction, University of Nottingham, Loughborough, Leics, UK.
Parkinson
T J
TJ
Hunter
M G
MG
Kelly
R W
RW
Lamming
G E
GE
D000818:Animals; D001826:Body Fluids / Q000737:chemistry; D002417:Cattle / Q000502:physiology*; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D003340:Corpus Luteum Maintenance / Q000502:physiology*; D015232:Dinoprostone / Q000032:analysis / Q000502:physiology*; D005260:Female; D007986:Luteinizing Hormone / Q000494:pharmacology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D011374:Progesterone / Q000096:biosynthesis; D014599:Uterus / Q000378:metabolism
D011374:Progesterone; D007986:Luteinizing Hormone; D015232:Dinoprostone