Effects of age and hypertension on α1-adrenoceptors in the major source arteries of the rat bladder and penis

• Published in: European journal of pharmacology 2011-11, Vol.670 (1), p.260-265
• Main Authors: Yono, Makoto, Tanaka, Takanori, Tsuji, Shigeki, Irie, Shin, Sakata, Yukikuni, Otani, Masayuki, Yoshida, Masaki, Latifpour, Jamshid
• Format: Article
• Language: English
• Subjects: age; Aging; Aging - metabolism; Aging - physiology; animal models; Animals; Arterial hypertension. Arterial hypotension; Arteries - metabolism; Arteries - physiology; Arteries - physiopathology; Biological and medical sciences; Bladder; Blood and lymphatic vessels; Blood Circulation; blood flow; blood pressure; Cardiology. Vascular system; Hypertension; Hypertension - metabolism; Hypertension - physiopathology; iliac artery; Male; Medical sciences; messenger RNA; Penis; Penis - blood supply; pharmacology; Pharmacology. Drug treatments; Rat; Rats; Receptors, Adrenergic, alpha-1 - genetics; Receptors, Adrenergic, alpha-1 - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Urinary Bladder - blood supply; Vascular α1-adrenoceptor
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/j.ejphar.2011.08.010

α1-Adrenoceptors regulate blood pressure, regional vascular resistance and tissue blood flow. As aging and hypertension may impact pelvic arterial blood flow resulting in bladder and penile dysfunction, we investigated effects of age and hypertension on α1-adrenoceptors in the major source arteries of the rat bladder and penis. Using radioligand receptor binding, real-time reverse transcription-polymerase chain reaction (RT-PCR) and fluorescent microsphere infusion techniques, we compared 3 and 22-month-old male Fischer rats, and male normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs). Twenty-two-month-old rats and SHRs had significantly higher total α1-adrenoceptor density in the internal iliac artery and lower blood flow to the bladder and penis than 3-month-old and WKY rats, respectively. RT-PCR data showed an age and hypertension related increase in the expression of α1B-adrenoceptor mRNA in the internal iliac, vesical and internal pudendal arteries and a switch from α1A predominance in 3-month-old and WKY rats to α1B>α1A in 22-month-old rats and SHRs. Our data indicate the presence of age and hypertension related alterations in vascular α1-adrenoceptor subtype distribution and in blood flow to the rat bladder and penis. These findings suggest that pharmacological blockade of the vascular α1B-adrenoceptor, which could increase pelvic blood flow, may contribute to the improvement of bladder and penile dysfunctions in animal models for aging and hypertension.