Alteration of vascular response to norepinephrine, calcitonin gene-related peptide, and acetylcholine in orchidectomized rats.
Abstract
AIM: To determine the long-term effects of orchidectomy on vasoreactivity.
METHODS: Orchidectomized rats with or without hormone replacement were raised 1,
2, and 4 months. Vascular responses to norepinephrine, calcitonin gene-related
peptide (CGRP), and acetylcholine were tested on three different arteries
(thoracic aorta, pulmonary artery, and caudal artery) by functional experiments.
RESULTS: Responses to norepinephrine, CGRP, and acetylcholine were not changed by
1 or 2 months deprivation of androgen. In aorta, the dose-response curve of CGRP
was shifted to the left by 1 month of testosterone replacement. Response to
norepinephrine was increased 4 months after orchidectomy and reversed by
testosterone replacement in thoracic aorta. Orchidectomy did not affect CGRP- and
acetylcholine-induced relaxation in all the arteries 4 months after orchidectomy.
CONCLUSION: Compared to estrogen, the protective effects of androgen on
vasoresponsiveness may be through inhibiting vasoconstriction, but is relatively
weak.
Keywords:
METHODS: Orchidectomized rats with or without hormone replacement were raised 1,
2, and 4 months. Vascular responses to norepinephrine, calcitonin gene-related
peptide (CGRP), and acetylcholine were tested on three different arteries
(thoracic aorta, pulmonary artery, and caudal artery) by functional experiments.
RESULTS: Responses to norepinephrine, CGRP, and acetylcholine were not changed by
1 or 2 months deprivation of androgen. In aorta, the dose-response curve of CGRP
was shifted to the left by 1 month of testosterone replacement. Response to
norepinephrine was increased 4 months after orchidectomy and reversed by
testosterone replacement in thoracic aorta. Orchidectomy did not affect CGRP- and
acetylcholine-induced relaxation in all the arteries 4 months after orchidectomy.
CONCLUSION: Compared to estrogen, the protective effects of androgen on
vasoresponsiveness may be through inhibiting vasoconstriction, but is relatively
weak.