Effects of natriuretic peptides on intracavernous pressure and blood pressure in conscious rats.
BACKGROUND
Natriuretic peptides activate particulate guanylyl cyclases and have been shown to induce penile erection in rats, rabbits, and humans.


OBJECTIVE
We investigated the effects of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) on intracavernous pressure (ICP) and systemic blood pressure (BP) in conscious, free-moving rats.


METHODS
ICP and BP were measured in male Sprague-Dawley rats after catheters were inserted into the crus corpus cavernosum and carotid artery, respectively. Natriuretic peptides were given by intravenous bolus (3, 10, and 30 nmol/kg) or continuous (0.1 and 1 nmol/kg/minute) administration.


METHODS
The number of animals with increases in ICP were determined. Amplitudes and durations of ICP responses and changes in BP were also evaluated.


RESULTS
More animals had multiple transient increases of ICP in response to ANP and BNP than to CNP. The increases in ICP were transient and appeared to be an "all or none" response. ANP and BNP decreased BP more than CNP, especially with bolus administration.


CONCLUSIONS
These findings show that in rats, erectile responses can be initiated by ANP, BNP, and less effectively, by CNP. ANP and BNP have a high affinity for the natriuretic peptide receptor-A, suggesting that this receptor is involved in the responses.
Aizawa
Naoki
N
Department of Urology, Shinshu University School of Medicine, Matsumoto, Japan. n-aizawa@hsp.md.shinshu-u.ac.jp
Ishizuka
Osamu
O
Ogawa
Teruyuki
T
Mizusawa
Hiroya
H
Igawa
Yasuhiko
Y
Nishizawa
Osamu
O
Andersson
Karl-Erik
KE
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D001794:Blood Pressure; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D020098:Natriuretic Peptide, C-Type / Q000378:metabolism; D045265:Natriuretic Peptides / Q000378:metabolism*; D010410:Penile Erection / Q000502:physiology*; D010413:Penis / Q000098:blood supply* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
D045265:Natriuretic Peptides; D020097:Natriuretic Peptide, Brain; D020098:Natriuretic Peptide, C-Type; D009320:Atrial Natriuretic Factor