Serum estradiol-17 beta, progesterone and respective uterine cytosol receptor concentrations in bitches with spontaneous pyometra.
The role of serum estradiol-17 beta (E(2)) and progesterone (P(4)) in relation to uterine estrogen (ER) and progesterone receptors (PR) was investigated in canine cystic endometrial hyperplasia-pyometra (CEH-P). Blood and uterine samples were collected pre- and post-ovariohysterectomy, respectively, from 54 bitches presenting spontaneous CEH-P and 25 healthy control bitches. Competitive enzyme immunoassays (EIA) and enzyme ligand immunoassays (ELIA) were applied to estimate serum hormones and uterine cytosol active receptors, respectively. Animals were classified in the stages of first half of diestrus, second half of diestrus and early anestrus on the basis of reproductive history, clinical signs, uterine and ovarian macro- and microscopic inspection and serum P(4) concentration. Bitches with CEH-P, compared to their respective stage controls, exhibited (a) similar P(4) fluctuations, (b) higher E(2) concentrations, (c) lower PR concentrations during diestrus first and second half and (d) lower ER concentrations during diestrus first half and early anestrus. Negative correlation was detected between P(4) and ER within both CEH-P and control groups. It was concluded that P(4) was the main uterine receptor regulator for both PR and ER during diestrus and early anestrus in healthy and affected uteri. However, in CEH-P bitches, high P(4) levels in diestrus appeared to over-activate uterine PRs, leading to stronger PR self-down regulation and ER suppression. These findings indicate an increased sensitivity of CEH-P uterus to P(4) action. During early anestrus, a complementary role of endogenous E(2) was considered, since reduction of P(4) action appeared to permit uterine ER replenishment and activation by relatively high E(2) levels.
Ververidis
Haralabos N
HN
Clinic of Obstetrics and Artificial Insemination, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki 546 27, Greece.
Boscos
Constantinos M
CM
Stefanakis
Alexandros
A
Saratsis
Philippos
P
Stamou
Anastasia I
AI
Krambovitis
Elias
E
D000818:Animals; D003600:Cytosol / Q000737:chemistry; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D004714:Endometrial Hyperplasia / Q000378:metabolism / Q000662:veterinary; D004958:Estradiol / Q000097:blood*; D005260:Female; D011374:Progesterone / Q000097:blood*; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D013492:Suppuration; D014591:Uterine Diseases / Q000378:metabolism / Q000662:veterinary*; D014599:Uterus / Q000648:ultrastructure
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011374:Progesterone; D004958:Estradiol