Suppression of 125I-vasoactive intestinal polypeptide binding sites in arteries of the hamster seminal vesicle following castration.
The presence and distribution of 125I-vasoactive intestinal polypeptide (VIP) binding sites in blood vessels supplying the hamster seminal vesicle was studied using a receptor autoradiographic technique before and following castration. 125I-VIP binding was studied in intact animals, in animals under a 15-day period of castration and in animals under the same period of castration but submitted to a further 15-day period of testosterone treatment. Our results show that, in the seminal vesicle, VIP-binding sites are localized in the gland smooth muscle coat and arterial smooth muscle. A 15-day castration period abolishes 125I-VIP binding to vascular smooth muscle but has no effect on 125I-VIP binding to the gland smooth muscle coat. Treatment with testosterone restores 125I-VIP binding to the vascular smooth muscle, completely reversing the effect of castration. Our results indicate that VIP-binding sites in the smooth muscle wall of arteries supplying the hamster seminal vesicle are under androgenic control and are more sensitive to androgen deprivation that VIP-binding sites associated to the gland smooth muscle coat.
Barroso
C P
CP
Gulbenkian Institute of Science, Oeiras, Portugal.
Afonso
F
F
Castro Caldas
M
M
Pinho
M
M
Mata
L
L
Gulbenkian
S
S
D000818:Animals; D001158:Arteries / Q000737:chemistry; D001345:Autoradiography; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology*; D002369:Castration; D003331:Coronary Vessels / Q000378:metabolism; D006224:Cricetinae; D007457:Iodine Radioisotopes; D008297:Male; D008647:Mesocricetus; D009130:Muscle, Smooth / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D012669:Seminal Vesicles / Q000098:blood supply*; D013739:Testosterone / Q000494:pharmacology*; D013997:Time Factors; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D007457:Iodine Radioisotopes; D014660:Vasoactive Intestinal Peptide; D013739:Testosterone