Category Archives: Ovarian

Vascular Remodeling and Angiogenesis: DISCUSSION(3)

Survival of follicles was spatially related to presence of pericytes rather than to endothelial cells in the area of the graft (Fig. 1, G-I; Fig. 2, A-O; Fig. 3, G-R). The ovarian cortex showed better follicular maintenance, probably due to sufficient blood supply (see Fig. 1I). Interestingly, Dissen et al. showed that the mRNA expression of the two angiogenic factors, VEGF and TGFp-1, is upregulated mainly at the ovarian cortex 48 h after transplantation. In the subcutaneous implants, no recovery of the initial damage was observed, whereas in the intramuscular grafts, improvement was observed within 6-7 days postimplantation, showing healthy follicular morphology and vascular integrity, including endothelial cells, pericytes, and SMC.

Vascular Remodeling and Angiogenesis: DISCUSSION(2)

DISCUSSION(2)

Ovarian fragments implanted intramuscularly showed much better follicular maintenance. Many follicles, from the primordial through the antral stages of development, could be found in the implant, suggesting recovery of ovarian function. At 6 days after implantation, the vasculature in the implant was very similar to that of control ovaries, with normal morphology of blood vessels. Despite this favorable outcome, necrotic regions in the medulla of the graft were detected at the first days (1-3 days) after transplantation, suggesting that early transitory necrosis may be overcome and the maintenance of the grafts improved at a later time (6-7 days). The medullar damage during the first hours after transplantation was accompanied by regression of pericytes and SMC, which was symptomatic of insufficient blood supply. generic geodon

Vascular Remodeling and Angiogenesis: DISCUSSION(1)

The role of vascularization in ovarian transplantation was studied here on a model system in which fresh fragments of rat ovaries (donor) were xenografted into female CD-1 nude mice (recipient). Two transplantation sites were compared, subcutaneous and intramuscular. Ovarian maintenance was markedly better in the intramuscular transplants. The rich blood supply within the muscle provided superior graft reception compared with that observed for the relatively poor supply of blood in the subcutaneous region. Substantial necrotic areas were detected in all the subcutaneous ovarian grafts, mainly in the medullar regions of the graft.

Vascular Remodeling and Angiogenesis: RESULTS(6)

RESULTS(6)

Changes in signal intensity reflective of vascular leakage were followed for 32 min (Fig. 6C). The accumulation of contrast agent was restricted to the graft and was not observed in the surrounding muscle (Fig. 6D). Histological staining of the biotinylated contrast agent was performed using avidin-FITC. Consistent with the MRI data, FITC staining was restricted to blood vessels within the muscle, whereas it leaked into the graft (Fig. 6E). The contrast agent was also detected in the follicular fluid. This leakage of the contrast agent in the ovarian grafts was similar to that observed in intact rats that were injected with the contrast agent intravenously 45 min prior to retrieval of the ovaries. Accordingly, the vascular properties of the ovarian grafts in the intramuscular transplantation appeared to be similar to those of the intact ovary.

Vascular Remodeling and Angiogenesis: RESULTS(5)

Dividing the intramuscular grafts into three groups according to the time after transplantation reveals that, during the short time periods of 1-3 days after transplantation, the ovaries scored —7.7 (n = 11), after 6-7 days, the score was 25.5 (n =;8), and at 28-31 days, the score was 8.0 (n = 7; Fig. 5). This scoring method reflects ovarian graft survival and was the lowest in the subcutaneous grafts throughout the 2-24 days after transplantation. The state of the intramuscular grafts was suboptimal during the first 3 days after transplantation; however, it improved after 6-7 days. After a period of about a month, a decrease in the follicular state was observed, although the grafts remained viable. The number of the small primordial follicles per square millimeter in the intramuscular site remained similar during the entire period examined (Fig. 4, D-F). canadian health & care mall

Vascular Remodeling and Angiogenesis: RESULTS(4)

RESULTS(4)Ovarian Preservation and Follicle Growth in the Grafts

We determined the state of grafted ovaries by the size and integrity of the follicles. Follicles were divided into seven groups according to their size, and both the viable and the atretic follicles were counted and graded. Grafts of half ovaries were assessed. In control ovaries, fixed immediately after the animal was killed (n = 3), all stages of follicular development were detected. In the controls, small atretic follicles were only rarely found at early stages of follicular development (Fig. 4A). In the subcutaneous ovarian grafts (n = 6; 2-24 days after transplantation), the largest viable follicles that were detected reached stage d (three layers of granulosa cells). A large number of degenerated primordial and primary follicles were detected (Fig. 4B).

Vascular Remodeling and Angiogenesis: RESULTS(3)

Kinetic Studies of Intramuscular Ovarian Transplantation

The subcutaneous grafts showed extensive damage during the first days after transplantation. Therefore, the intramuscular grafts were assessed at different time periods, from 1 to 31 days posttransplantation (Fig. 3). Half ovaries were transplanted into the gluteus superficialis at the hind limb. Of the 31 grafts, 26 were detected (Table 1). One of the ovaries retrieved 24 h after transplantation was found to be disconnected from the muscle (Fig. 3, A-C). In that ovary, both the follicles and the vasculature were extensively damaged. Similar to the subcutaneous transplants, at this early time point after transplantation, damage was also detected in ovaries that were in close contact with the muscular tissue. buy glucovance

Vascular Remodeling and Angiogenesis: RESULTS(2)

RESULTS(2)Intramuscular Ovary Transplantation: Optimization of Graft Size

Because the subcutaneous region is heterogeneous and relatively poor in its blood vessel support, we chose the muscle, which is more homogeneous and rich with vasculature, as a transplantation site. While the graft (in muscle as well as in the subcutaneous transplantations) should be large enough to contain the maximum pool of oocytes, it should also be small enough to minimize ischemia-reper-fusion injury. In order to optimize the graft size in the intramuscular transplantation, we studied various sizes of ovarian grafts, ranging from intact ovaries (6 mm3) to 1/8 ovary (0.75 mm3; Fig. 2).

Vascular Remodeling and Angiogenesis: RESULTS(1)

Subcutaneous Ovarian Transplantation

Ovaries of 15-day-old Wistar rats contain primordial, primary, and small antral follicles (Fig. 1A). The GSL-1 staining represents staining of endothelial cells (e.g., Fig. 1B) and aSMA staining represents SMC and pericytes (e.g., Fig. 1C).

Subcutaneous half ovarian grafts were examined at various time points during the first days after transplantation (Fig. 1, D-L). Out of the 13 grafts, only 6 provided identifiable follicles within the ovarian sections (Table 1). A gradual decrease in the overall preservation (follicle state, vascular integrity, and necrosis) of the ovarian grafts was observed. micronase dosage

Vascular Remodeling and Angiogenesis: MATERIALS AND METHODS(7)

METHODS(7)

We have applied a relative scale in order to estimate the condition of the ovary on the basis of follicle growth and viability. The seven follicle types were scored as follows: the viable ones received a positive grade from 1 to 7; the smallest one received a score of 1 and the largest one a score of 7. The atretic follicles were negatively scored, the smallest one received a score of —7 and the largest one received a score of —1. The rationale for this scoring system is based on the probability that small follicles being atretic is normally low, while as the follicles grow, their probability of being atretic is increased. Therefore, we assume that excessive atresia of small follicles in the transplants is the result of ovarian stress due to insufficient blood supply. Thus, atretic primordial follicles received the most negative score (—7). Viable antral follicles received the highest positive score (+7). Each follicle type was graded as follows: follicle grade X (total number of follicles from the specified type/total area of the examined ovary [mm2]). The total score of an ovary was obtained by summing up the scores of each follicle type.

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