Submission Number: HEI-4-35-22
Abstract Number: 399
EFFECTS OF PROLONGED PROGESTERONE, ESTROGEN, AND COMBINATION TREATMENT ON UBF REDISTRIBUTION AND TISSUE SPECIFIC eNOS EXPRESSION IN OVINE UTERINE MICROVASCULATURE.
Heidi L Rupnow 1, Terrance M Phernetton 1, ML Modrick 1, Cynthia E Shaw 1, Ian M Bird 1 and Ronald R Magness* 1,2
Perinatal Res. Labs., Depts. Ob/Gyn, Meriter Hospital, Madison, WI 1
Department of Animal Sciences, University of Wisconsin, Madison, WI 2
UBF and uterine artery eNOS expression are greatest during the follicular versus luteal phase of the cycle. Treatment with Estradiol-17 (E2B) increases UBF and uterine artery eNOS expression. Purpose: To evaluate the effects of Progesterone (P4 ) E2B on UBF redistribution to the Endometrium (Endo), Myometrium (Myo), and Caruncles (Car) in relation to eNOS expression in the regional uterine microvasculature. Methods: Nonpregnant ovariectomized sheep received either Vehicle (V; n=9), P4 (0.9g CIDRS vaginal implants; n=7), E2B(5g/kg bolus followed by 6g/kg/d; n=9), or P4 + E2B(n=7) with radioactive microspheres injected into the left ventricle to determine UBF distribution at control and 10 days. Other nonpregnant ovariectomized sheep received the same treatments for 10 days (V n=9; P4 n=9; E2B n=9; P4 + E2B n=7) and Endo, Myo, and Car microvessels were procured; eNOS protein expression was quantified by Western analysis and scanning densitometry. Results: Prolonged E2B and P4 + E2B increased (P<0.05) UBF (ml/min) to the Endo, Myo, and Car while P4 alone had no effect vs. V. With E2B the percent of total UBF was significantly increased in the Myo and significantly decreased in the Car. P4 alone increased UBF redistribution to the Endo and Car, but in combination with E2B they decreased distribution to the Myo. E2B alone and P4 + E2B (P<0.05) increased eNOS expression in Myo microvessels (V = 10026%, E2B = 28279%, P4 + E2B = 23557% of V). The exogenous steroid-induced increase in eNOS levels was specific to the Myo since neither Car nor Endo eNOS expression was altered. Conclusion: E2B redistributed total UBF to the Myo, while E2B and P4 + E2B increased eNOS expression in Myo microvessels. There was no effect of hormone treatment on eNOS expression in Endo and Car microvessels, however P4 was able to increase blood flow redistribution to these regions. Support: NIH HL49210; HD33255; HL56753; HL56702.
Keywords: UBF, eNOS
This abstract is being presented at: 8:00 AM in session: