Effect of single dose aspirin on the development of penile hypercoagulability during erection

Long-Term Aspirin Administration Has No Effect on Erectile Function: Evidence from Adult Rats and Ageing Rat Model

As the broad spectrum pharmacological action, aspirin has been one of the most widely used medicines since its initial synthesis; however, the association between aspirin and erectile function is still controversial. We aim to explore whether long-term aspirin administration deteriorates or preserves erectile function from adult rats and ageing rat model. Twenty adult rats (10 weeks of age) and twenty ageing rats (80 weeks of age) were randomly divided into four groups as follows: Adult-Control (normal saline [NS]), Adult-Aspirin (aspirin, 10 mg/kg/d), Ageing-Control (NS), and Ageing-Aspirin (aspirin, 10 mg/kg/d) groups (n = 10 per group). For all rats, erectile function was assessed by maximum intracavernous pressure (ICP), total area under ICP curve (AUC), ICP/mean arterial pressure (MAP) ratio, and MAP. The total treatment duration was one month. Protein expression levels of cyclooxygenase-1 (COX-1), COX-2, endothelial nitric oxide synthase (eNOS), and nNOS of the corpus cavernosum were detected by Western blot. ELISA kits were used to determine 6-keto PGF_1a, PGE₂, TXB₂, cyclic adenosine monophosphate (cAMP), and cyclic guanosine monophosphate (cGMP) levels. Total nitric oxide (NO) concentration was measured using a fluorometric assay kit. As a result, Ageing-Control rats revealed significantly decreased ICP, AUC, and ICP/MAP ratios compared to Adult-Control rats, and these effects were accompanied by reduced eNOS protein expression and lower total NO and cGMP levels; however, no difference was found in nNOS protein expression. For adult rat groups, aspirin significantly inhibited the production of 6-keto PGF_1a, PGE₂, and TXB₂; however, it neither changed the ICP, AUC, or ICP/ MAP ratios nor altered the protein expression of eNOS, nNOS, COX-1, and COX-2. Meanwhile, aspirin did not influence the concentrations of total NO, cAMP, or cGMP. The same tendency was also found in the ageing rat model, which confirmed that aspirin did not alter erectile function. Our data suggested that long-term aspirin administration did not strengthen or weaken erectile function in adult rats or ageing rat model. Thus, it had no impact on erectile function.

Association between use of aspirin or non-aspirin non-steroidal anti-inflammatory drugs and erectile dysfunction: A systematic review

OBJECTIVE

There are various etiologies of erectile dysfunction (ED), including endothelial dysfunction, atherosclerosis, and chronic inflammation. Aspirin has a protective role against endothelial dysfunction and atherosclerosis, whease all non-steroidal anti-inflammatory drugs (NSAIDs) are known for their anti-inflammatory properties. However, association between the use of aspirin or non-aspirin NSAIDs and ED is controversial. Therefore, we reviewed this relationship.

METHODS

We systematically reviewed the pathophysiology of ED, physiological effect of prostaglandins, pharmacological action of NSAIDs, and clinical and basic research studies that evaluated the effect of aspirin or non-aspirin NSAIDs on ED.

RESULTS

The research studies that assessed association between aspirin or non-aspirin NSAIDs are limited, and only 12 articles have been published. One clinical and three basic studies have claimed that aspirin or non-aspirin NSAIDs are beneficial for ED by preserving nitric oxide synthase impairment or penile blood hypercoagulability. One basic and two clinical studies considered them as risk factors because they interfered with prostaglandin production. By contrast, four clinical studies showed irrelevant results after controlling various medical indications. In addition, the mechanical effect of aspirin or non-aspirin NSAIDs on the nitric oxide pathway is still controversial.

CONCLUSIONS

The available research studies revealed that association between aspirin or non-aspirin NSAIDs and ED is controversial. Considering the high frequency of drug use, further clinical and basic investigations should be conducted to clarify their exact relationship.

Acetylsalicylic acid protects erectile function in diabetic rats

We aimed to evaluate the effect of acetylsalicylic acid (ASA) treatment on diabetes-induced erectile dysfunction. Adult male Sprague-Dawley rats were divided into four groups as follows: (i) control (C), (ii) diabetic (D), (iii) ASA-treated control (C+ASA) and (iv) ASA-treated diabetic (D+ASA) groups. In groups 2 and 4, diabetes was induced by injection of 35 mg kg(-1) streptozotocin. ASA (100 mg kg(-1) day(-1) , orally) was administrated to rats in groups 3 and 4 for 8 weeks. Both intracavernosal pressure (ICP) and mean arterial blood pressure (MAP) were measured in in vivo studies. In organ bath, the relaxation responses to acetylcholine (ACh), electrical field stimulation (EFS) and sodium nitroprusside were tested in corpus cavernosum (CC) strips. The mRNA expression for neuronal nitric oxide synthase (nNOS) was calculated using reverse transcription polymerase chain reaction technique. In in vivo experiments, diabetic rats displayed reduced ICP/MAP values, which were normalised with ASA treatment. The relaxant response to high-dose ACh and EFS at low frequencies (1-8 Hz) in CC strips from the D+ASA group were significantly higher when compared to the D group. Treatment with ASA normalised the raised mRNA expressions of nNOS in diabetic penile tissues. ASA may be involved in mRNA of protein synthesis of NO released from nonadrenergic and noncholinergic cavernosal nerve in diabetes.

Functional inhibition of erectile process in rats by indomethacin

OBJECTIVES

Despite the important role played by prostaglandins in the control of erection, the potential contribution of non-steroidal anti-inflammatory drugs in erectile dysfunction in experimental animals has not been investigated. We examined the effect of the selective COX-2 inhibitor, celexocib, and the non-selective COX-inhibitors, indomethacin and diclofenac on erectile process in vivo.

METHODS

Erectile responses to electrical stimulation of the cavernous nerve in anesthetized male rats were recorded after single and repeated administration and intracavernosal pressure/mean arterial pressure (ICP/MAP) was calculated. The effect on blood pressure during erection and total plasma nitrite/nitrate level was also investigated.

RESULTS

Single-dose administration of indomethacin significantly reduced erectile responses to electrical stimulation at all frequencies tested; 15 mg/kg further reduced ICP/MAP to 0.016 ± 0.005 compared to 0.064 ± 0.012 and 0.104 ± 0.035 for indomethacin (5 mg/kg) and control, respectively at 0.5 Hz. Longer-term treatment with indomethacin completely abolished erectile responses at low frequencies and significantly reduced ICP/MAP at higher frequencies, accompanied by significant reduction in total plasma nitrite/nitrate level. Diclofenac reduced erectile responses only at low frequencies in contrast to celexocib that failed to negatively affect erectile responses.

CONCLUSION

Indomethacin, and to a lower extent diclofenac, may adversely affect erectile responses in rats.