The primary source of steroid hormone production in mice is the corpora lutea of the ovaries throughout pregnancy, whereas humans undergo a luteal-placental shift of steroid production during pregnancy.
In the corpora lutea of the Dll4 antibody-treated marmosets, blood vessels appear to have invaded almost every possible space between the hormone-producing cells and appeared more elongate than in controls (Fig. 1, J and K).
In addition, larger luteal areas (two, two, two, and three per animal) were observed which were deemed to be the corpora lutea of the treatment cycle that had been responsible for progesterone secretion at the start of the treatment phase.
Atp5a1 showed diffuse staining in all compartments of the ovary except the corpora lutea (Fig. 4G), whereas, within the ovary, Ell2 is detected only in the corpora lutea (Fig. 4H).
To further evaluate whether the effect of the F. lutea extract was being mediated via the insulin tyrosine kinase receptor or related pathways, the effect of insulin alone was compared to that with concurrent F. lutea, or to F. lutea alone.
The central region of the retina contains the macula lutea, which receives focused incoming light and is responsible for providing acute vision.
In the luteal microvasculature, the number of proliferating endothelial cells was increased by treatment and, as a result, the area occupied by the endothelium in the corpora lutea was significantly increased by d 3 after treatment.
With only the F. lutea extract being effective, the activity of the F. lutea extract in the presence of insulin was investigated.
One such method could involve evaluating the effects of the F. lutea acetone extract on glucose concentrations and/or tyrosine kinase activities, in the presence of an antagonist of the insulin receptor.
In the presence 1 μM and 10 μM insulin the F. lutea extract significantly (p<0.05) increased the glucose uptake in the C2C12 muscle cells [13.0 ± 0.6 μg/ml (19.5 ± 0.7%) and 13.9 ± 1.4 μg/ml (20.8 ± 1.6%) respectively] at the highest concentration of 500 μg/ml compared to the F. lutea extract alone.
CD31 staining alone revealed the extent of the microvascular tree in the corpora lutea (see low-power magnification in Fig. 1, G and H).
