Some steroids in the blood of mares suffering from endometritis and post-partum mares as compared to normal cycling mares
Nitschelm, D.; van der Horst, C.J.
Tijdschrift Voor Diergeneeskunde 101(20): 1154-1162
1976
ISSN/ISBN: 0040-7453 PMID: 1013974 Document Number: 96322
Mares aged 3-15 years, affected with endometritis, had increased concentrations of certain steroids on the first day of heat (normally below 1 ng/ml). Values for normal animals were: pregnenolone 8 ng/ml, compound "5.4" 4 ng/ml, progesterone 4 ng/ml. All these levels fell to 1 ng/ml or less at ovulation. During the first week after foaling the levels were: progesterone 4 ng/ml, compound "5.4" 80 ng/ml. However, immediately before the onset of heat these values fell to 1 ng/ml and 6 ng/ml, respectively. The increase in the levels of these hormones is considered to influence the ovaries by reducing or blocking follicular growth. They may be responsible for anoestrus after parturition or in endometritis as well as for the ineffectiveness of prostaglandins in the presence of raised blood progesterone levels.