Progesterone is a steroid hormone which is produced by maturing follicles and by the corpora lutea
. Frequent cause of infertility is seen in the dog due to inappropriate breeding time.
These differences might be attributed to the increased number of corpora lutea
formed from increased number of ovulated follicles during the first month of pregnancy , which consequently secreted adequate quantities of progesterone in response to luteinizing hormone (LH) levels.
The changes were most pronounced in the pregnant sows' corpora lutea
, endometria, hearts and skeletal muscle.
The ovaries were weighed and the corpora lutea
In addition, visible antral follicles and corpora lutea
was demonstrated on the ovarian tissues upon transplantation.
Synchronized follicular development and abundant corpora lutea
(CL) were observed which showed normal follicular maturation and ovulation in control mice.
Cystic corpora lutea
are usually not larger than 3 cm in diameter and wall is about 5-10 mm thick.
In mice and rats, the corpora lutea
are the main source of P4 that will support the gestation process.
Furthermore, we observed a rise in the number of atretic follicles and corpora lutea
in group B.
During pregnancy, progesterone is mainly produced by corpora lutea
(CL) and placenta and, to a lesser extent, adrenal cortex [13-16].
A large number of ovarian follicles in different stages of development (primordial, primary, preantral, and antral follicles) and corpora lutea
with radial strands of luteum cells were separated by a stroma.