Modulation of aortic vascular reactivity by sex hormones in a male rat model of metabolic syndrome.
Modulation by sex hormones of aortic reactivity in rats with the metabolic syndrome (MS) was investigated. The following groups of weanling male Wistar rats were used: control rats (C) received regular tap water while MS rats received 30% sucrose in their drinking water; both had rodent chow for 24 weeks. These two groups were further subdivided into the following four groups: intact (Int), castrated (Cas), castrated plus testosterone (T) and castrated plus estradiol (E). Vascular response of thoracic aortic rings to norepinephrine (NE), acetylcholine (ACh), indomethacin (Indo) and nitro-l-arginine-methyl ester (L-NAME) was investigated. Blood pressure (BP) and serum nitrates and nitrites were measured. BP and serum nitrates and nitrites were modified by castration and treatments with either T or E. Vasoconstriction in Int MS and Cas MS+T aortas was larger than in C and Cas C+T, respectively. Vasodilation in Int MS and Cas MS+T was reduced in comparison with C and Cas C+T, Cas MS and Cas MS+E. Indomethacin decreased vasoconstriction in all groups (P<0.002) but Int C and Cas C+T remained significantly smaller than Int MS and Cas MS+T. l-NAME in NE-contracted vessels induced a significant increase in vasoconstriction, except in Cas C+E rats; the responses of Int MS and Cas MS+T were significantly larger than in Int C and Cas C+T. The results suggest endothelial dysfunction in Int MS and Cas MS+T and a protective effect resulting from castration and castration plus E in MS animals, indicating a sex hormone influence.
Torres
Israel Pérez
IP
Department of Pathology, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México.
Hafidi
Mohammed El
ME
Biochemistry, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México.
Zamora-González
José
J
Endocrinology, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México.
Infante
Oscar
O
Instrumentation, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México.
Chavira
Roberto
R
Department of Reproduction Biology, Instituto Nacional de la Nutrición "Salvador Zubirán". Vasco de Quiroga 15. Sección XVI, Tlalpan, 14080 México DF, México.
Baños
Guadalupe
G
Biochemistry, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México. Electronic address: gbanos@yahoo.com.
D000818:Animals; D001011:Aorta / Q000473:pathology*; D001794:Blood Pressure; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000166:cytology / Q000473:pathology; D004958:Estradiol / Q000378:metabolism; D012739:Gonadal Steroid Hormones / Q000378:metabolism; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D024821:Metabolic Syndrome / Q000378:metabolism* / Q000473:pathology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013395:Sucrose / Q000494:pharmacology; D013739:Testosterone / Q000378:metabolism
D012739:Gonadal Steroid Hormones; D013739:Testosterone; D004958:Estradiol; D013395:Sucrose; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin