Ovarian Blood Flow Research Articles

The effect of exogenous estradiol benzoate and altrenogest on uterine and ovarian blood flow during the estrous cycle in mares

In recent years, a positive relationship between genital perfusion and fertility has been established; in species other than horses, uterine and ovarian perfusion was improved by exogenous estrogen but impaired by exogenous progestin. The goal of the present study was to investigate the effect of exogenous estrogen and progestin on uterine and ovarian blood flow in cycling mares. Five Trotter mares were examined daily during three estrous cycles. Mares were given no treatment, altrenogest (0.044 mg/kg BW) orally from Day 0 (ovulation) to Day 14 and estradiol benzoate (5 mg i.m.) on Days 0, 5, and 10, in three cycles, respectively. There was no difference ( P>0.05) in the length of untreated versus estrogen-treated cycles (22.8±1.3 days and 23.2±1.5 days, respectively), but cycle length was increased ( P<0.05) in progestin-treated cycles (26.0±1.2 days). To facilitate comparisons among cycles with different lengths, data from Days 0 to 15 (diestrus) and from Days −6 to −1 (estrus) were analyzed. Transrectal Doppler sonography was used to evaluate blood flow in both uterine arteries and in the ovarian artery ipsilateral to the preovulatory follicle during estrus and ipsilateral to the corpus luteum during diestrus. Blood flow was assessed semiquantitatively using the pulsatility index (PI); high PI values indicated high resistance and a low perfusion and vice versa. An immediate effect of treatments occurred only after the administration of estradiol benzoate on Day 0; uterine PI values decreased ( P<0.05) between Days 0 and 1 and estrogen-treated mares but increased ( P<0.05) at the corresponding time in untreated cycles. Mean PI values for the uterine and ovarian arteries during both diestrus and estrus were higher ( P<0.05) in estrogen-treated versus untreated mares. Furthermore, mean uterine PI values during diestrus and estrus were higher ( P<0.05) in altrenogest-treated versus untreated mares. Neither estrogen nor altrenogest treatments had a significant immediate effect on ovarian PI values. Compared to untreated cycles, mean ovarian PI values were elevated ( P<0.05) only in the estrus following altrenogest administration. In conclusion, exogenous estrogen and progestin both decreased genital perfusion in cycling mares.

Ovarian blood flow responses to electro-acupuncture stimulation at different frequencies and intensities in anaesthetized rats

The purpose of the present study was to investigate changes in ovarian blood flow (OBF) in response to electro-acupuncture (EA) stimulation at different frequencies and intensities in anaesthetized rats. Whether the ovarian sympathetic nerves were involved in OBF responses was elucidated by severance of the ovarian sympathetic nerves. In addition, how changes in the systemic circulation affected OBF was evaluated by continuously recording blood pressure. OBF was measured on the surface of the left ovary using laser Doppler flowmeter. Acupuncture needles with a diameter of 0.3 mm were inserted bilaterally into the abdominal and the hindlimb muscles and connected to an electrical stimulator. Two frequencies—2 Hz (low) and 80 Hz (high)—with three different intensities—1.5, 3, and 6 mA—were applied for 35 s. Both low- and high-frequency EA at 1.5 mA and high-frequency EA at 3 mA had no effect on OBF or mean arterial blood pressure (MAP). Low-frequency EA at 3 and 6 mA elicited significant increases in OBF. In contrast, high-frequency EA with an intensity of 6 mA evoked significant decreases in OBF, followed by decreases in MAP. After severance of the ovarian sympathetic nerves, the increases in the OBF responses to low-frequency EA at 3 and 6 mA were totally abolished, and the responses at 6 mA showed a tendency to decrease, probably because of concomitant decreases in MAP. The decreased OBF and MAP responses to high-frequency EA at 6 mA remained after the ovarian sympathectomy, and the difference in the responses before and after ovarian sympathectomy was nonsignificant. In conclusion, the present study showed that low-frequency EA stimulation increases OBF as a reflex response via the ovarian sympathetic nerves, whereas high-frequency EA stimulation decreases OBF as a passive response following systemic circulatory changes.

Impaired ovarian blood flow and reduced antral follicle count following laparoscopic salpingectomy for ectopic pregnancy.

Whether salpingectomy affects ovarian function is controversial. In this study, ovarian function was assessed by antral follicle count, ovarian volume and ovarian stromal blood flow measured by three-dimensional (3D) power Doppler ultrasonography. The objectives of the study were to compare the ovarian function of the operated side with the non-operated side after unilateral salpingectomy performed through laparoscopy or laparotomy for ectopic pregnancy. Thirty-two patients with unilateral salpingectomy performed for ectopic pregnancy were recruited: 18 through laparoscopy and 14 through laparotomy. Ultrasound scans were performed in the early follicular phase. Ovarian volume, antral follicle count and 3D power Doppler indices were comparable between the operated and the non-operated sides in the whole group and in the laparotomy group. The antral follicle count and 3D power Doppler indices were significantly reduced on the operated side in the laparoscopy group. Ovarian function seems to be impaired after laparoscopic unilateral salpingectomy at short-term assessment.

The effect of acetylsalicylic acid and captopril on uterine and ovarian blood flow during the estrous cycle in mares

In previous studies, transrectal color Doppler sonography was used to demonstrate an increase in genital blood flow resistance in subfertile mares. The objectives of the present study were to determine the effects of an anticoagulant (acetylsalicylic acid) and a vasodilator (captopril) on uterine and ovarian perfusion and plasma progesterone concentrations in cycling mares. From Day 1 to 11 of an estrous cycle (Day 0=day of ovulation following prostaglandin-induced luteolysis), five Trotter mares were given 2500 mg lactose, 2500 mg ASA, or 50 mg captopril twice daily in their feed (one compound per cycle, in random order). Transrectal color Doppler sonography was used to examine both uterine arteries and the ovarian artery ipsilateral to the corpus luteum once daily, immediately prior to administration of the drug. Blood flow resistance was determined semiquantitatively using the pulsatility index (PI) and plasma progesterone concentrations were determined with an enzyme immunoassay. Compared to the placebo, both ASA and captopril decreased mean PI values of both uterine arteries of all mares. On average, ASA decreased the PI of the uterine arteries by 25%; this was more ( P<0.05) than the average decrease (13%) caused by captopril. Both drugs decreased ( P<0.05) blood flow resistance in the ovarian arteries, although there was no difference ( P<0.05) in their efficacy. In addition, both ASA and captopril increased ( P<0.0001) plasma progesterone concentrations (18 and 17%, respectively). In conclusion, either ASA or captopril improved uterine and ovarian perfusion; however the effects on fertility were not determined.

Comparison of follicular blood flow and follicular fluid concentrations of vascular endothelial growth factor and nitric oxide as prognostic factors in the outcome of in vitro fertilization

Objectives: The aims of this prospective study were to investigate the relationship between the outcome of in vitro fertilization and follicular blood flow, ovarian blood flow, and the follicular fluid concentration of vascular endothelial growth factor and nitric oxide to determine whether these factors might be outcome predictors. Design: This study was performed in 47 cycles who underwent in vitro fertilization with tubal factor (25 cycles) and male factor (22 cycles) at infertility clinic of Pusan National University Hospital from Feb. 2002 to June 2002. Materials and Methods: Ultrasound images of follicular and ovarian blood flow were estimated on the day of hCG administration. Each follicular fluid (FF) was collected at the oocyte retrieval and FF concentrations of vascular endothelial growth factor (VEGF) and nitric oxide(NO) were assessed. FF VEGF concentrations were measured using an enzyme-linked immunosorbent assay (Quantikine Human VEGF Immunoassay, R&D Systems Inc., Minneapolis, MN, USA). FF concentrations of nitrite/nitrate were determined colorimetrically by the Griess reaction. The color reaction was allowed to develop for 5 min at room temperature, after which the absorbance at 540 nM was recorded. Results: Follicular blood flow was significantly increased in the pregnant group compared to the nonpregnant group. However, age, dosage of gonadotropin administered, estradiol on hCG day, the number of oocytes retrieved, fertilization rate, No. of embryos transferred, ovarian blood flow, and FF concentrations of VEGF and NO were not significantly different in two goups. There were no differences in any clinical and laboratory parameters including the number of oocytes retrieved, fertilization rate, No. of embryos transferred, pregnancy rate, FF concentrations of VEGF and NO, and follicular blood flow according to the causes of infertility or age. As folliclular size increases, follicular blood flow and FF concentration of VEGF concentration were increased, but FF concentration of NO were decreased. No correlation existed between FF concentrations of VEGF and NO. The number of oocytes retrieved, the number of mature oocytes, and fertilization rate were not correlated with ovarian blood flow and FF concentrations of VEGF and NO. Conclusions: These results suggest that follicular blood flow might be an effective prognostic marker of the pregnancy outcome of in vitro fertilization rather than FF concentrations of VEGF or NO, and demonstrate that follicular blood flow and FF concentration of VEGF and NO were correlated significantly with follicular size. However, these study do not show that age was correlated with FF concentrations of VEGF and NO, ovarian blood, or follicular blood flow.

Changes in ovarian blood flow and follicular dynamics in anovulatory women with PCOS undergoing IVM

Objective: The objective of this study was to evaluate ovarian perfusion in the early and late follicular phase using 3-dimensional power Doppler ultrasonography, as well changes in the number and sizes of the follicles present in non-cycling polycystic ovaries (PCO). Design: An observational study of 23 patients with anovulatory PCOS undergoing in vitro maturation treatment (IVM). Materials and Methods: Patients undergoing IVM underwent a baseline 2-dimensional ultrasound scan between days 2 to 4 following a progesterone withdrawal bleed. An antral follicle count was performed with follicles grouped to either < than or ≥4mm in diameter. A 3-dimensional power Doppler scan was performed to assess ovarian volume and perfusion. Patients were then reassessed between days 8 to 10. The 3-dimensional power Doppler scans were analysed using VOCAL software to determine the vascular indices (VI, FI, VFI). Paired sample t testing was used for statistical analysis. Results: Twenty-three women were included in the study. The mean age of the patients was 32.3 years. The mean total number of follicles on day 8 to 10 was higher than on days 2 to 4 but this did not reach significance. There was a trend towards a larger number of follicles ≥4mm on days 8 to10 but there was no difference in the number of follicles < 4mm in diameter between evaluations. There was a trend to a larger ovarian volume with the later scan. The mean vascularization index (VI) on day 8 to 10 was 16.1% (SD 8.7%), which was significantly higher than the mean VI on day 2 to 4 (12.8%, SD 6.0, p<0.001). The mean flow (FI) and vascularization-flow (VFI) indices on day 8 to 10 were 38.8 (SD 8.7) and 6.5 (SD 3.9) respectively, both of which were significantly higher than on day 2 to 4 (FI=37.3, SD 2.8, VFI= 4.9, SD 2.3, p<0.0001). Conclusion: This study demonstrates that anovulatory polycystic ovaries are not static but demonstrate changes in follicular dynamics and perfusion with cycle progression. The most significant changes relate to ovarian perfusion. VI is a measure of vessel density and so an elevation may imply some degree of neoangiogenesis as the cycle progresses. FI is an estimation of intensity of flow and VFI is an estimation of total perfusion within a selected volume. The significant increases in these indices would imply a total higher ovarian perfusion with cycle progression.

Effect of tubal sterilization on ovarian follicular reserve and function

OBJECTIVE: Tubal ligation may reduce the ovarian blood flow and lead to tissue damage to the ovary. If so, this may also result in a significant decrease of the total follicular pool. We performed a long-term evaluation of ovarian reserve and function after tubal sterilization in a longitudinal prospective comparison cohort. STUDY DESIGN: In an university tertiary-care center, 26 women undergoing laparoscopic tubal sterilization with the use of bipolar coagulation, and 26 matched control subjects underwent measurement of follicle-stimulating hormone, luteinizing hormone, 17β-estradiol, and inhibin on menstrual cycle day 3 before (baseline) and at 6, 12, 18, 24, and 60 months after the sterilization for ovarian reserve evaluation. At baseline and 12 and 24 months after tubal ligation, women who underwent sterilization were sampled every other day across an entire menstrual cycle for follicle-stimulating hormone, luteinizing hormone, 17β-estradiol, inhibin, and progesterone determination to evaluate ovarian function. RESULTS: No significant changes were observed either within or between groups for any parameter, despite the fact that a 45% and 30% increase in follicle-stimulating hormone concentration from baseline to the 60-month control was detected in tubal sterilization and control groups of women, respectively. No significant changes were observed in the mean area under the curve of follicle-stimulating hormone, luteinizing hormone, estradiol, inhibin, and progesterone per menstrual cycle at baseline and 12 and 24 months after sterilization. CONCLUSION: This 5-year follow-up study suggests that there is neither an accelerated decline of ovarian follicular reserve nor ovarian dysfunction after tubal sterilization by electrocoagulation.

Ovarian blood flow is reflexively regulated by mechanical afferent stimulation of a hindlimb in nonpregnant anesthetized rats

The effects of mechanical afferent stimulation of either a hindpaw or a hind leg on ovarian blood flow and systemic arterial blood pressure were studied in anesthetized nonpregnant adult female rats. Ovarian blood flow at the left side was continuously measured using a laser Doppler flowmeter. A mechanical stimulus (by pinching, brushing or pressing) was delivered for 30 s to either a hindpaw or a hind leg, at the right or left side. Pinching of a hindpaw at the right or left side decreased ovarian blood flow 8±3% accompanied with an increase in blood pressure. Brushing or pressing of a hindpaw produced no effects on these two parameters measured. Pressing stimulation of a hind leg at the right or left side produced a decrease in ovarian blood flow 8±2% accompanied with a decrease in blood pressure. Pinching or brushing of a hind leg produced no effects on both parameters measured. All responses of ovarian blood flow and blood pressure mentioned above were abolished after severing the femoral and sciatic nerves at the same side in which stimulation was unilaterally delivered. The blood pressure response, either increased or decreased depending on the stimulus modality and location stimulated, was not influenced by severing of ovarian sympathetic nerves. However, the decrease response in ovarian blood flow following pinching of a hindpaw reversed to the increase response, while the decrease response in ovarian blood flow following pressing of a hind leg was slightly augmented. The activity of sympathetic nerves innervating the ovary was increased during pinching of a hindpaw of either side, and decreased during pressing of a hind leg of either side. Electrical stimulation of the distal part of the severed splanchnic nerve at the left side decreased the left ovarian blood flow, and this response was abolished by intravenous injection of phentolamine, the α-adrenoceptor antagonist. The present results demonstrate that ovarian blood flow increase or decrease passively to responses of an increase or a decrease in systemic arterial blood pressure following mechanical afferent stimulation of a hindlimb, and these passive responses of ovarian blood flow are modulated by reflexive activity of ovarian sympathetic vasoconstrictor nerves to attenuate blood pressure-dependent passive changes in ovarian blood flow.

Effects of Metformin on the Uterine and Ovarian Stromal Blood Flow in Women with Polycystic Ovary Syndrome

Objective: To investigate the influence of metformin on the uterine and ovarian stromal blood flow in women with polycystic ovary syndrome (PCOS). Material(s) and Method(s): Thirty-six infertile patients with PCOS were included initially. These patients received metformin treatment for three months with a dosage of 500 mg three times daily. During the period of this study, 13 patients dropped out of the study. Finally, 23 cases had undertaken blood flow assessment of bilateral uterine and ovarian stromal arteries before and after 3-month treatment by the conventional transvaginal color Doppler ultrasonography. The pulsatility index (P1) and resistance index (RI) of the bilateral uterine and ovarian stromal arteries were measured. The data before treatment were compared with the ones after treatment. Among them, the pregnant patients were further identified and received another analysis to compare the changes after metformin treatment. Result(s): When comparing the vascular impedance of all the patients before and after metformin treatment, the P1 and RI of the bilateral uterine and ovarian stromal arteries showed no significant differences. In addition, in the seven patients (30.4%) who were pregnant, the vascular impedance of these pregnancy women did not have significant differences while compared with that of these non-pregnancy women who also received metformin treatment. Conclusion(s): Although some previous studies reported that metformin might improve regional blood flow, no significant changes in the vascular impedance of uterine and ovarian flow after metformin treatment can be observed in this study. Besides, no differences in the P1 or RI of the uterine and ovarian arteries were found in the pregnant women after treatment, which implies that metformin may not ameliorate blood flow indexes in PCOS women. However, the underlying effect of metformin to PCOS remains to be solved and further studies are needed.

Evaluation of the impact of laparoscopic ovarian drilling on Doppler indices of ovarian stromal blood flow, serum vascular endothelial growth factor, and insulin-like growth factor-1 in women with polycystic ovary syndrome

Objective To study the serum levels and correlation of vascular endothelial growth factor (VEGF), insulin-like growth factor 1 (IGF-1), hormonal profile, and Doppler blood flow changes within the ovarian stroma before and after laparoscopic ovarian drilling (LOD) in women with clomiphene-resistant polycystic ovary syndrome (PCOS). Design Prospective controlled study. Setting University teaching hospital. Patient(s) Twenty-five women with clomiphene-resistant PCOS (group 1) and 20 women with regular menstrual cycles as a comparison group (group 2). Intervention(s) Laparoscopic ovarian drilling. Main outcome measure(s) Serum levels of VEGF, IGF-1, and Doppler indices of ovarian stromal blood flow. Result(s) The serum levels of VEGF, IGF-1, T, and LH were significantly higher in group 1 before LOD than in group 2. The Doppler indices (pulsatility index and resistance index) of ovarian stromal blood flow were also significantly lower in group 1 before LOD than in group 2. The serum levels of VEGF, T, and LH were significantly reduced in group 1 after LOD compared with in group 1 before LOD. Doppler indices (pulsatility index and resistance index) of ovarian stromal blood flow were significantly increased after LOD. The VEGF levels before LOD were positively correlated with IGF-1, LH, and T. After LOD, the VEGF levels were positively correlated with LH and T. Conclusion(s) Higher serum levels of VEGF and IGF-1 may explain the increased vascularity that was demonstrated by Doppler blood flow measurements in PCOS. Laparoscopic ovarian drilling reduced serum VEGF, IGF-1, T, and LH and reduced ovarian blood flow velocities, which may explain the reduction of ovarian hyperstimulation syndrome in women with PCOS after LOD.

The effect of semen extender, seminal plasma and raw semen on uterine and ovarian blood flow in mares.

Transrectal color Doppler sonography was used to evaluate the effect of intrauterine infusion of skim milk semen extender, seminal plasma and raw semen on the endometrium and blood flow in the uterine and ovarian arteries in mares. Six Trotter mares (mean age: 12 years) were examined during estrus in three cycles. Each mare received an intrauterine infusion of 20 ml of skim milk semen extender, seminal plasma or raw semen during estrus in one of three cycles. Blood flow measurements in both uterine and ovarian arteries and the determination of intrauterine fluid via sonography were performed before each infusion and 1, 3, 6, 12, and 24 h after infusion. Forty-eight hours later, the intrauterine infusion and measurements were repeated using the same time intervals. Changes in blood flow were detected using transrectal color Doppler sonography and were evaluated using the mean time-averaged maximum velocity (TAMV) of the blood flow. Cytological and bacteriological examination of uterine swabs performed 48 h after the second infusion revealed less inflammation and bacterial growth in mares infused with skim milk semen extender than in those infused with seminal plasma or raw semen. There was an increase in intrauterine fluid as early as 1 h after infusion of any of the substances. The infusion of skim milk semen extender had no effect on uterine blood flow. Within 1 h after infusion of seminal plasma or raw semen, there was an increase in the TAMV values of both uterine arteries (P<0.05). In contrast, ovarian blood flow increased only in the artery ipsilateral to the preovulatory follicle and only after the infusion of raw semen (P<0.05). In conclusion, the changes in uterine perfusion observed after intrauterine infusion may be associated with endometrial inflammation and vasodilatory components in the seminal plasma, whereas the changes seen in ovarian blood flow are possibly attributable to the interaction between sperm and oviduct.

Role of the angiotensin II system in regulation of ovulation and blood flow in the rat ovary.

The aim of the present study was to examine the roles of the angiotensin II receptor subtypes, AT(1) and AT(2), in ovulation, and to evaluate the contribution of angiotensin II-mediated pathways in regulation of ovarian blood flow. The AT(1)-specific antagonist, losartan, was administered alone or in combination with the AT(2)-specific antagonist, PD123319, to preovulatory rat ovaries perfused in vitro. Losartan (100 micromol l(-1)) did not affect the number of ovulations, whereas the combination of losartan (100 micromol l(-1)) and PD123319 (10 micromol l(-1)) inhibited ovulation. The angiotensin II antagonists did not affect the ovarian production of oestradiol, progesterone, prostaglandin E(2) (PGE(2)), PGF(2 alpha) or plasminogen activator activity. Ovarian nitric oxide production was inhibited by losartan. Ovarian blood flow was measured by laser Doppler flowmetry in vivo in preovulatory rat ovaries. Intrabursal injection of angiotensin II reduced ovarian blood flow of gonadotrophin-stimulated rats. Losartan had no effect on basal ovarian blood flow but completely blocked the angiotensin II-induced reduction. In contrast, treatment with PD123319 increased basal ovarian blood flow and failed to reverse the effect of exogenously administered angiotensin II, indicating that under physiological conditions, ovarian blood flow of the rat is negatively regulated by angiotensin II mainly through the action of AT(2). Taken together, these results indicate that two different types of angiotensin II receptor facilitate ovulation by cooperative mechanisms and that they regulate ovarian blood flow in a different manner.

Role of the angiotensin II system in regulation of ovulation and blood flow in the rat ovary

The aim of the present study was to examine the roles of the angiotensin II receptor subtypes, AT(1) and AT(2), in ovulation, and to evaluate the contribution of angiotensin II-mediated pathways in regulation of ovarian blood flow. The AT(1)-specific antagonist, losartan, was administered alone or in combination with the AT(2)-specific antagonist, PD123319, to preovulatory rat ovaries perfused in vitro. Losartan (100 micromol l(-1)) did not affect the number of ovulations, whereas the combination of losartan (100 micromol l(-1)) and PD123319 (10 micromol l(-1)) inhibited ovulation. The angiotensin II antagonists did not affect the ovarian production of oestradiol, progesterone, prostaglandin E(2) (PGE(2)), PGF(2 alpha) or plasminogen activator activity. Ovarian nitric oxide production was inhibited by losartan. Ovarian blood flow was measured by laser Doppler flowmetry in vivo in preovulatory rat ovaries. Intrabursal injection of angiotensin II reduced ovarian blood flow of gonadotrophin-stimulated rats. Losartan had no effect on basal ovarian blood flow but completely blocked the angiotensin II-induced reduction. In contrast, treatment with PD123319 increased basal ovarian blood flow and failed to reverse the effect of exogenously administered angiotensin II, indicating that under physiological conditions, ovarian blood flow of the rat is negatively regulated by angiotensin II mainly through the action of AT(2). Taken together, these results indicate that two different types of angiotensin II receptor facilitate ovulation by cooperative mechanisms and that they regulate ovarian blood flow in a different manner.

P139: Effects of a copper medicated intrauterine device on uterine, intrauterine and ovarian arterial blood flow

P139: Effects of a copper medicated intrauterine device on uterine, intrauterine and ovarian arterial blood flow

Colour Doppler analysis of ovarian and uterine arteries in women with hypoestrogenic amenorrhoea.

This is a clinically-controlled study designed to investigate uterine and ovarian blood flow in patients with hypoestrogenic amenorrhoea. Twelve women with hypoestrogenic amenorrhoea and 13 eumenorrhoeic subjects (controls) were enrolled. Colour and pulsed Doppler was used to visualize the uterine and ovarian arteries and the blood vessels within the ovarian stroma in both groups. Four blood flow indices were calculated: the pulsatility index, the resistance index, the peak systolic velocity and the end-diastolic velocity. Peak systolic velocity underwent the most significant change in amenorrhoeic patients, being significantly lower in comparison with that of controls, both in the uterine (P = 0.0009) and ovarian (P = 0.001) arteries. Compared with controls, the end-diastolic velocity of the ovarian artery was significantly lower (P = 0.039) in amenorrhoeic patients, and was also lower in the uterine artery (though not statistically significantly so). A reduction in blood flow was also evident in the ovarian stroma in amenorrhoeic patients. The significant reduction in blood flow observed in hypoestrogenic amenorrhoea suggests that estrogens play an important role in regulating both uterine and ovarian blood flow.

Embolic microspheres within ovarian arterial vasculature after uterine artery embolization

BACKGROUND: Adverse events after uterine artery embolization, including hysterectomy and premature ovarian failure, are concerning for women who desire future fertility. CASE: A 39-year-old woman underwent emergency hysterectomy after uterine artery embolization embolic microspheres found within the ovarian arterial vasculature. CONCLUSION: Uterine artery embolization for the treatment of uterine fibroids has been associated with loss of ovarian function in up to 14% of patients. This case report demonstrates that embolic microspheres injected into the uterine artery can unintentionally migrate through anastomotic channels into the ovarian arterial vasculature and potentially compromise ovarian blood flow. Hypoxic tissue injury may be the mechanism of premature ovarian failure observed after uterine artery embolization. Understanding the etiology of premature ovarian failure after uterine artery embolization might allow better patient selection.

Nitric oxide regulates ovarian blood flow in the rat during the periovulatory period.

The aim of this study was to characterize the roles of nitric oxide (NO) on the rat ovarian blood flow (OBF) during the preovulatory period. Immature Sprague-Dawley rats were primed with pregnant mares' serum gonadotrophin (PMSG, 15 IU) and given hCG (15 IU) 48 h later. The ovary was exposed 48-56 h after PMSG, a laser Doppler probe was attached to the ovarian surface and OBF was measured at two time periods: preovulatory (PO) 48 h after PMSG and ovulatory (OV) 6-8 h after hCG. A non-selective NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), was injected i.v. (4 and 10 mg/kg) or intrabursally (1 mg/kg). Intravenous administration of L-NAME to OV rats rapidly increased blood pressure and reduced OBF by 30%, which returned to the pretreatment level within 30 min. L-NAME given into the ovarian bursa of both PO and OV rats did not affect blood pressure and reduced OBF by nearly 40%, which remained low throughout the experiment. Intravenous injection of hCG to PO rats increased OBF to 116.1% at 5 min and 133.5% at 30 min in relation to the pretreatment level. When L-NAME was given intrabursally, subsequent hCG injection was without effect. These results indicate that locally produced NO is important for the maintenance and increase of rat OBF during the preovulatory period.

Three-dimensional sonographic and power Doppler characterization of ovaries in late follicular phase.

To determine ovarian blood flow characteristics using three-dimensional power Doppler ultrasound. We examined 30 patients (30 cycles) prior to the start of their in vitro fertilization treatment in the late follicular phase using three-dimensional power Doppler ultrasound. The volume, vascularization index, flow index, vascularization flow index, mean grayness and the presence of the dominant follicle were determined for each ovary separately. The dominant follicle could be detected in 24 out of 30 cycles (80.0%). The volume of the dominant ovary was 9.9 (standard deviation, 4.0) cm3 and the volume of the non-dominant ovary 6.8 (standard deviation, 2.8) cm3 (P < 0.001). Mean grayness in the dominant ovary was 43.3 (standard deviation, 5.0) and in the non-dominant 47.2 (standard deviation, 4.0) (P < 0.001), but no other differences could be observed between dominant and non-dominant ovaries. The shell with a diameter of 2 mm surrounding the dominant follicle had a higher vascularization index (mean, 9.0; standard deviation, 5.9) and vascularization flow index (mean, 4.2; standard deviation, 2.8) than the whole dominant ovary (mean, 5.5; standard deviation, 2.5 and mean, 2.5; standard deviation, 1.3, respectively) (P = 0.003 and 0.002, respectively). In the cycles without a dominant follicle (n = 6), flow index (mean, 50.0; standard deviation, 5.9) and vascularization flow index (mean, 7.3; standard deviation, 6.2) on the left side were higher than on the right side (mean, 40.2; standard deviation, 3.1; mean, 1.5; standard deviation, 1.4; P-values 0.013 and 0.046, respectively). In the dominant ovary, the volume was higher and mean grayness lower than in the non-dominant ovary. The vascularization index in the shell surrounding the dominant follicle was higher than the average vascularization index in the whole dominant ovary. In addition, there were differences in the vascularization and flow indices between right and left ovaries, which may be related to the anatomical difference in the venous drainage between right and left ovaries.

Effect of raloxifene on the ovarian circulation in women after menopause

Objective: We sought to determine whether raloxifene effects the ovarian circulation in women after menopause. Study Design: The resistance indices of the ovarian blood flow were assessed in 130 women after menopause who were randomly assigned to receive either 60 mg of raloxifene, a continuous combined estrogen-progestin tablet daily, or neither treatment for 24 months. Results: The women who received raloxifene or hormonal replacement therapy had a significant time-related decrease in the resistance index of the ovarian artery blood flow compared to baseline values (resistance index, 0.91) starting after 12 and 18 months of treatment (resistance index, 0.88 and 0.89, respectively; P <.002 and.001, respectively). Whereas significant increases in the resistance index respective to the prestudy values were observed in the nontreated women at 24 months (resistance index, 0.93; P <.0001). The mean (±SD) resistance index of the ovarian blood flow at the end of the study (resistance index, 0.89) was significantly lower in the women who were treated with raloxifene than in the women who were treated with hormone replacement therapy (P <.002). No changes in the ovarian dimensions or appearance were noticed during the entire study. Conclusion: Daily therapy with raloxifene has significant ovarian vascular-relaxing effect in women after menopause. This potentially important direct vasculoprotective long-term effect of raloxifene on cardiovascular disease deserves further investigation. (Am J Obstet Gynecol 2002;186:984-9.)

Uterine and ovarian blood flow during the estrous cycle in mares

Uterine and ovarian blood flow was investigated in four mares during two consecutive estrous cycles using transrectal color Doppler sonography. The uterine and ovarian arteries of both sides were scanned to obtain waves of blood flow velocity. The pulsatility index (PI) reflected blood flow. There were significant time trends in PI values of all uterine and ovarian blood vessels during the estrous cycle ( P<0.05). PI values did not differ between the uterine arteries ipsi- and contralateral to the corpus luteum or the ovulatory follicle. PI values of the uterine arteries showed a wave shaped profile throughout the estrous cycle. The highest PI values occurred on Days 0 and 1 (Day 0=ovulation) and around Day 11, and the lowest PI values were measured around Days 5 and −2 of the estrous cycle. During diestrus (Days 0–15) PI values of the ovarian artery ipsilateral to the corpus luteum were significantly lower than PI values of the contralateral ovarian artery ( P<0.0001). No differences ( P>0.05) in resistance to ovarian blood flow occurred between sides during estrus (Days −6 to −1). In this cycle stage PI values decreased in both ovarian vessels ( P<0.05). During diestrus, high PI values of the ovarian artery ipsilateral to the corpus luteum were measured between Days 0 and 2, followed by a decline until Day 6 ( P<0.05). From this time on, the resistance to blood flow increased continuously until Day 15 ( P<0.05). The cyclic blood flow pattern in the contralateral ovarian artery was similar to that in the uterine arteries ( r=0.68; P<0.0001). No correlations occurred between the diameter of the corpus luteum and the PI values of the ipsilateral ovarian artery ( P>0.05) during diestrus. During estrus, there was a negative relationship between growth of the diameter of the ovulatory follicle and changes in PI values of the dominant ovarian artery ( r=−0.41; P<0.05). PI values of the uterine arteries and of the ovarian artery ipsilateral to the ovulatory follicle were negatively related to estrogen (E) levels in plasma during estrus (uterine arteries: r=−0.21; P<0.05; dominant ovarian artery: r=−0.35; P<0.05). In diestrus, PI values of the dominant ovarian artery were negatively related to plasma progesterone levels ( r=−0.38; P<0.0001), but not the PI values of the uterine arteries ( P>0.05). The findings of this study show that there are characteristic changes in blood supply of the uterus and the ovaries throughout the equine estrous cycle. There are negative correlations between resistance to blood flow in the uterine and ovarian arteries and the plasma estrogen levels during estrus. In diestrus, there is a negative relationship between the resistance to ovarian blood flow and the progesterone levels.