Effect of an angiotensin II receptor blocker and a calcium channel blocker on hypertension associated penile dysfunction in a rat model

Red wine but not alcohol consumption improves cardiovascular function and oxidative stress of the hypertensive-SHR and diabetic-STZ rats

AIMS

This raised the issue of whether in vivo long-term red wine treatment can act as a modulator of these targets.

MAIN METHODS

We monitored SBP, glucose tolerance, oxidative stress, and cardiovascular function. Aortic and atrial tissues from normotensive-WKY, hypertensive-SHR, and diabetic-STZ animals, chronically exposed to red wine (3.715 ml/kg/v.o/day) or alcohol (12%) for 21-days, were used to measure contractile/relaxation responses by force transducers. Key findings: red wine, but not alcohol, prevented the increase of SBP and hyperglycemic peak. Additionally, was observed prevention of oxidative stress metabolites formation and an improvement in ROS scavenging antioxidant capacity of SHR. We also revealed that red wine intake enhances the endothelium-dependent relaxation, decreases the hypercontractile mediated by angiotensin-II in the aorta, and via β₁-adrenoceptors in the atrium.

SIGNIFICANCE

The long-term consumption of red wine can improve oxidative stress and the functionality of angiotensin-II and β₁-adrenoceptors, inspiring new pharmacologic and dietetic therapeutic approaches for the treatment of hypertension and diabetes.Abbreviation Acronyms and/or abbreviations: [Ca²⁺]_cyt = Cytosolic Ca²⁺ Concentration; ACh = Acetylcholine; ANG II = Angiotensin II; AT1 = ANG II type 1 receptor; AUC = Area Under the Curve; Ca²⁺ = Calcium; Endo + = Endothelium Intact; Fen = Phenylephrine (1 μM); GTT = Glucose Tolerance Test; ISO = Isoprenaline (isoproterenol); KHN = Krebs-Henseleit Nutrient; LA = Left Atria; LH = Lipid Hydroperoxide; NO = Nitric Oxide; RA = Right Atria; RAS = Renin-Angiotensin System; ROS = Reactive Oxygen Species; SBP = Systolic Blood Pressure; SHR = Spontaneously Hypertensive Rats; STZ = Streptozotocin; WKY = Normotensive Wistar Kyoto Rats.

Physiology of Erection and Pathophysiology of Erectile Dysfunction

The science of penile erection, including recent advances in its molecular physiology and neuroanatomic pathways, is described. The pathophysiology of erectile dysfunction is presented, acknowledging associated disease states, and accordingly follows a practical classification scheme: vasculogenic, neurogenic, endocrine, and psychogenic.

Effect of prescription medications on erectile dysfunction

Erectile dysfunction (ED) affects about 50% of men in the USA and is primarily attributed to physiological (organic) and psychological causes. However, a substantial portion of men suffer from ED due to iatrogenic causes. Common medications such as antihypertensives, non-steroidal anti-inflammatory drugs and antacids may cause ED. Physicians should be aware of the various prescription medications that may cause ED to properly screen and counsel patients on an issue that many may feel too uncomfortable to discuss. In this review, we discuss the physiology, data and alternative therapies for the ED caused by medications.

Preserved Erectile Function in the Aged Transgenic Rat Harboring Human Tissue Kallikrein 1

INTRODUCTION

Human tissue kallikrein 1 (hKLK1) has enormous potential for the protection of vasodilation and endothelial function in the cardiovascular system. Our previous study proved the decreased expression of kallikrein 1 in the corpus cavernosum (CC) of aged rats, but the role of kallikrein 1 in age-related erectile dysfunction remains unknown.

AIM

To explore the effect and underlying mechanisms of hKLK1 on age-related erectile dysfunction.

METHODS

Male wild-type Sprague-Dawley rats (WTR) and transgenic rats harboring the hKLK1 gene (TGR) were fed to 4 and 27 months of age, respectively, and divided into four groups: young WTR (yWTR) as the control, young TGR (yTGR), aged WTR (aWTR), and aged TGR (aTGR). Rats' erectile function was evaluated by the cavernous nerve electrostimulation method. Then, CCs were collected for verification of hKLK1 followed by measurement of nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) and RhoA-Rho-kinase (ROCK) signaling activities. Masson trichrome staining and terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling assay were conducted to evaluate penile fibrosis and apoptosis.

MAIN OUTCOME MEASURES

Erectile response, NO-cGMP and RhoA-ROCK pathway-related indices, ratio of smooth muscle to collagen, and apoptosis index.

RESULTS

The hKLK1 alleviated the decrease of erectile function in the aWTR group. Endothelial NO synthase (eNOS) and phospho-eNOS(Ser1177) expressions, NO synthase activity, and NO and cGMP levels were decreased, whereas phospho-eNOS(Thr495), L-type Ca(2+) channel, RhoA, ROCK1, ROCK2, and transforming growth factor β1 proteins were increased in the CCs of the aWTR group compared with the control yWTR group. These changes were obviously mitigated in the aTGR group. Moreover, hKLK1 prevented the sharp decrease of the ratio of smooth muscle to collagen and the increase of the apoptosis index in the CCs of the aWTR group.

CONCLUSION

These results suggest that hKLK1 could play a preventive role in age-related erectile dysfunction by activation of the NO-cGMP pathway and inhibition of the RhoA-ROCK pathway and by antitissue fibrotic and apoptotic effects.

The Different Therapeutic Choices with ARBs. Which One to Give? When? Why?

The renin-angiotensin-aldosterone system plays an important role in the pathophysiology of hypertension and is closely related with cardio- and cerebrovascular events and chronic kidney diseases. Each angiotensin receptor blocker (ARB) is important in the treatment of hypertension, according to the results of recent years. This is a practical review of the available evidence on the different benefits of ARBs beyond their blood pressure-lowering effect, with an emphasis on the differences found between the particular compounds and the therapeutic implications of the findings, with specific reference to the co-morbidities.