Different effect of losartan and amlodipine on penile structures in male spontaneously hypertensive rats.
BACKGROUND
Erectile dysfunction is highly prevalent in hypertensive patients. Since both angiotensin II receptor type-1 blockers (ARBs) and calcium antagonists are current and effective antihypertensive drugs, the aim of this study was to determine possible differences between ARBs and calcium antagonists concerning the protection of penile structures from the deleterious effects of arterial hypertension.


RESULTS
During 6 months, 3 groups of male spontaneously hypertensive rats (SHR) and 1 of Wistar-Kyoto (WKY) rats, as a control group, were studied: SHR without treatment; SHR with losartan (L) 30 mg/kg/day; SHR with amlodipine (A) 3 mg/kg/day, and WKY without treatment. Cavernous smooth muscle (CSM) and vascular smooth muscle (VSM) from cavernous arteries, cavernous tissue fibrosis and collagen type III (COL III) were evaluated. After 6 months, SHR+L and SHR+A showed a similar reduction in blood pressure compared with untreated SHR. However, only SHR+L and control WKY presented significantly lower values of: CSM (p < 0.01), VSM (p < 0.01), and COL III (p < 0.01) when compared with either untreated SHR or SHR+A. There was also a positive correlation between left ventricular mass and proteinuria with VSM from cavernous arteries, CSM and COL III in untreated SHR and SHR+A. These relations were not present in SHR+L and WKY.


CONCLUSIONS
Although losartan and amlodipine achieved similar blood pressure control, losartan but not amlodipine showed a significant protective role against structural changes in the vessels and cavernous spaces of the erectile tissue caused by arterial hypertension.
Toblli
Jorge Eduardo
JE
Laboratory of Experimental Medicine, Hospital Alemán, Buenos Aires, Argentina. jtoblli@hospitaleman.com
Stella
Inés
I
Mazza
Osvaldo Néstor
ON
Ferder
León
L
Inserra
Felipe
F
D017311:Amlodipine / Q000494:pharmacology*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology*; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000473:pathology; D004359:Drug Therapy, Combination; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D006977:Hypertension, Renal / Q000150:complications* / Q000473:pathology; D006984:Hypertrophy; D019808:Losartan / Q000494:pharmacology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000473:pathology; D010413:Penis / Q000098:blood supply; D011507:Proteinuria / Q000188:drug therapy / Q000473:pathology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014665:Vasodilator Agents / Q000494:pharmacology*
D047228:Angiotensin II Type 1 Receptor Blockers; D014665:Vasodilator Agents; D017311:Amlodipine; D019808:Losartan