Advanced

Enhancement of apomorphine-induced penile erection in the rat by a selective alpha(1D)-adrenoceptor antagonist.

Mizusawa, Hiroya; Hedlund, Petter LU ; Sjunnesson, Johan; Brioni, Jorge D; Sullivan, James P and Andersson, Karl-Erik LU (2002) In British Journal of Pharmacology 136(5). p.701-708
Abstract
Effects of A-322312 (alpha(1B)-adrenoceptor (AR) antagonist), A-119637 (alpha(1D)-AR antagonist), prazosin (non-selective alpha(1)-AR antagonist), and yohimbine (alpha(2)-AR antagonist) were studied in rat corpus cavernosum (CC) and cavernous artery (Acc) preparations. Effects of intracavernous (i.c.) or intraperitoneal (i.p.) administration of alpha(1)-AR antagonists on apomorphine-induced erections were investigated. A-119637 attenuated electrically induced contractions in isolated CC (-logIC(50); 8.12+/-0.15), and relaxed noradrenaline (NA)-contracted preparations by more than 90% at 10(-7) M. At the same concentration, the -logEC(50) value for NA in Acc was altered from 6.79+/-0.07 to 4.86+/-0.13. In the CC and Acc, prazosin similarily... (More)
Effects of A-322312 (alpha(1B)-adrenoceptor (AR) antagonist), A-119637 (alpha(1D)-AR antagonist), prazosin (non-selective alpha(1)-AR antagonist), and yohimbine (alpha(2)-AR antagonist) were studied in rat corpus cavernosum (CC) and cavernous artery (Acc) preparations. Effects of intracavernous (i.c.) or intraperitoneal (i.p.) administration of alpha(1)-AR antagonists on apomorphine-induced erections were investigated. A-119637 attenuated electrically induced contractions in isolated CC (-logIC(50); 8.12+/-0.15), and relaxed noradrenaline (NA)-contracted preparations by more than 90% at 10(-7) M. At the same concentration, the -logEC(50) value for NA in Acc was altered from 6.79+/-0.07 to 4.86+/-0.13. In the CC and Acc, prazosin similarily inhibited contractile responses. Inhibitory effects of A-322312 (10(-7) M) in electrically activated CC were 32.3+/-5.1%, whereas no effect on concentration-response curves for NA was observed in the Acc. Yohimbine (10(-8) M and 10(-7) M), enhanced electrically-induced contractions in isolated CC by 20 to 50%. At 10(-6) M, inhibitory effects of yohimbine were obtained. A-119637 (0.3 micromol kg(-1), i.p.) tripled the number of erections, and produced a 6 fold increase in the duration of apomorphine-induced erectile responses. A-322312, prazosin, or yohimbine did not enhance erections induced by apomorphine. None of the alpha(1)-AR antagonists significantly increased ICP upon i.c. administration. Decreases in blood pressure were seen with A-119637 and prazosin. The present findings show that there is a functional predominance of the alpha(1D)-AR subtype in the rat erectile tissue, and that blockade of this receptor facilitates rat penile erection induced by a suboptimal dose of apomorphine. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
British Journal of Pharmacology
volume
136
issue
5
pages
701 - 708
publisher
The British Pharmacological Society
external identifiers
  • pmid:12086979
  • wos:000176685200008
  • scopus:0035987778
ISSN
1476-5381
DOI
10.1038/sj.bjp.0704773
language
English
LU publication?
yes
id
d23beaa2-6272-4b9d-81e2-0e0950c0f72e (old id 109057)
alternative location
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12086979&dopt=Abstract
date added to LUP
2007-07-05 14:06:21
date last changed
2017-10-22 04:39:57
@article{d23beaa2-6272-4b9d-81e2-0e0950c0f72e,
  abstract     = {Effects of A-322312 (alpha(1B)-adrenoceptor (AR) antagonist), A-119637 (alpha(1D)-AR antagonist), prazosin (non-selective alpha(1)-AR antagonist), and yohimbine (alpha(2)-AR antagonist) were studied in rat corpus cavernosum (CC) and cavernous artery (Acc) preparations. Effects of intracavernous (i.c.) or intraperitoneal (i.p.) administration of alpha(1)-AR antagonists on apomorphine-induced erections were investigated. A-119637 attenuated electrically induced contractions in isolated CC (-logIC(50); 8.12+/-0.15), and relaxed noradrenaline (NA)-contracted preparations by more than 90% at 10(-7) M. At the same concentration, the -logEC(50) value for NA in Acc was altered from 6.79+/-0.07 to 4.86+/-0.13. In the CC and Acc, prazosin similarily inhibited contractile responses. Inhibitory effects of A-322312 (10(-7) M) in electrically activated CC were 32.3+/-5.1%, whereas no effect on concentration-response curves for NA was observed in the Acc. Yohimbine (10(-8) M and 10(-7) M), enhanced electrically-induced contractions in isolated CC by 20 to 50%. At 10(-6) M, inhibitory effects of yohimbine were obtained. A-119637 (0.3 micromol kg(-1), i.p.) tripled the number of erections, and produced a 6 fold increase in the duration of apomorphine-induced erectile responses. A-322312, prazosin, or yohimbine did not enhance erections induced by apomorphine. None of the alpha(1)-AR antagonists significantly increased ICP upon i.c. administration. Decreases in blood pressure were seen with A-119637 and prazosin. The present findings show that there is a functional predominance of the alpha(1D)-AR subtype in the rat erectile tissue, and that blockade of this receptor facilitates rat penile erection induced by a suboptimal dose of apomorphine.},
  author       = {Mizusawa, Hiroya and Hedlund, Petter and Sjunnesson, Johan and Brioni, Jorge D and Sullivan, James P and Andersson, Karl-Erik},
  issn         = {1476-5381},
  language     = {eng},
  number       = {5},
  pages        = {701--708},
  publisher    = {The British Pharmacological Society},
  series       = {British Journal of Pharmacology},
  title        = {Enhancement of apomorphine-induced penile erection in the rat by a selective alpha(1D)-adrenoceptor antagonist.},
  url          = {http://dx.doi.org/10.1038/sj.bjp.0704773},
  volume       = {136},
  year         = {2002},
}