The direct effects of progesterone/progestin on vascular tone.
- Author:
Soo Hyun CHO
1
;
Seung Ryong KIM
;
Kyoung Hun KIM
;
Jung Kook SUH
Author Information
1. Department of Obstetrics and Gynecology, College of Medicine, Hanyang University.
- Publication Type:In Vitro ; Original Article
- Keywords:
Estrogen;
Progesterone;
Progestin;
Artery;
Relaxation
- MeSH:
Animals;
Aorta;
Aorta, Thoracic;
Arteries;
Baths;
Estradiol;
Estrogens;
Female;
Medroxyprogesterone Acetate;
Microcomputers;
Norepinephrine;
Norethindrone;
Ovariectomy;
Poaceae;
Progesterone;
Rats;
Relaxation;
Steroids;
Transducers
- From:Korean Journal of Obstetrics and Gynecology
2001;44(7):1232-1236
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVES: To evaluate the effects of progesterone/progestin and in combination with estrogen in relaxation of rat aorta. METHODS: Eight weeks after bilateral oophorectomy, the descending aorta of Spague-Dawley rats (n=10) were quickly removed and placed in organ bath containing Krebs solution. Each aorta ring in 2-3 mm length was connected to an isometric force transducer (FT 03, Grass, USA) and the changes in tension were recorded with an AD converter system (MP 100, Biopac Inc, USA) in a personal computer. After precontraction of the rings with norepinephrine (1 umol/L) or KCl (40 mmol/L), estradiol, progesterone, medroxyprogesterone acetate (MPA), norethisterone acetate (NETA) (10-5-10-8 M/L in each) were added to each ring and they were incubated for 15 minutes. The relaxation was expressed as a percentage of the tonic contraction. RESULTS: Estrogen relax the aorta in all concentrations. The degree of relaxation was dose dependent (P<0.001). All of the progesterone, MPA, NETA relax the aorta and the effects was different according to the concentration of steroids (P<0.0001). The degree of relaxation was not different between estrogen and those of progesterone, MPA, NETA except MPA 10-8 M, NETA 10-5 M. Addition of progesterone, MPA and NETA to the estrogen showed similar vascular effects compared to those of estrogen alone. CONCLUSION: Not only estrogen but also progesterone, MPA, and NETA acutely relax aorta. Progesterone/progestin have not been found attenuate the action of estrogen in our animal in vitro study.
