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Heart failure (HF) is a major public health issue, with an increasing prevalence in the world. Studies have shown a strong association of HF with development of low urinary tract symptoms (LUTS), where approximately 34% of men and 62% of women with HF reported having LUTS. Moreover, 57% of these HF patients present with overactive bladder syndrome. Dysfunction of the autonomic nervous system and alterations in important signaling pathways such as the nitric oxide/cyclic guanosine monophosphate pathway (NO‐GCs‐GMPc) are present in the HF. Therefore, drugs were synthesized to potentiate the effect exerted by NO, such as Tadalafil. Recent studies have shown that daily treatment with Tadalafil has been effective in decreasing symptoms related to urination and urine storage, in addition to improving the quality of life of patients with LUTS who have or not associated erectile dysfunction. Thus, using the aortocaval fistula model (FAC) we investigated the contribution of chronic treatment with tadalafil in the cardiovascular dysfunction and low urinary tract alterations of HF rats. HF was surgically induced through the FAC model and after 8 weeks of the surgical procedure the animals were divided into 4 groups: Sham and HF (0.9% saline solution) and Sham/Tadalafil and HF/Tadalafil (tadalafil 5mg/day for more 4 weeks). After 12 weeks, HF group presented increased left ventricle (LV) mass, decreased ejection fraction and increased LV end‐systolic and diastolic volumes when compared to the respective Sham group (p<0.05). However, tadalafil treatment restored cardiac function in the HF/Tadalafil group, with a decreased in hypertrophy and an improved in LV function when compared to the HF group (p<0.05). In addition, in the assessment of isolated detrusor contractile response (in vitro) to carbachol, KCl, alpha‐beta methyl ATP and EFS were increased in the HF group (p<0.05) compared to Sham group. In agreement with these findings, changes in cystometric parameters also were observed in vivo, with an increased in baseline pressure, threshold pressure, number of involuntary contractions and decreased bladder capacity in the HF group (p<0.05), when compared to the respective Sham. However, after treatment with tadalafil, the HF/Tadalafil group showed a decreased in contractile hyperactivity mediated by carbachol, KCl, alpha‐beta methyl ATP and EFS, as well as restoration of urinary function assessed by cystometry (p<0.05) compared to HF group. Renal function and the REDOX also were changed in the HF group, with increased urea plasma levels, as well as changes in REDOX balance, with increased lipoperoxidation and decreased total antioxidant capacity and activity Enzymatic activity of the superoxide dismutase. However, treatment with tadalafil was able to restore urea levels, decrease lipoperoxidation and increase the activity of the antioxidant system in the HF group (p<0.05). Therefore, chronic treatment with tadalafil showed cardioprotective effect and reversed the detrusor overactivity (in vitro) with improved urinary function (in vivo), as well as restoring renal function and REDOX balance in HF animals.Support or Funding InformationFundação de Amparo à Pesquisa do Estado de São Paulo ‐ FAPESP

IntroductionHeart failure (HF) is the common endpoint of several cardiovascular diseases. HF and ED share similar pathophysiological mechanisms that contribute to the progression of both disorders, with emphasis on endothelial dysfunction and reduced nitric oxide (NO) bioavailability. Drugs mimic the effect exerted by NO, such as tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor used in the ED treatment. Therefore, tadalafil may be a multi‐therapeutic agent in the treatment of cardiovascular alterations and erectile dysfunction associated with impaired of NO‐sGC‐cGMP signaling pathway? Thus, using the aortocaval fistula model (FAC) we investigated the contribution of tadalafil chronic treatment in the cardiac, vascular and erectile dysfunction of HF rats.MethodsHF was surgically induced through the FAC model, and after 8 weeks, these animals were submitted to cardiac function evaluation (echocardiogram) and subdivided into 3 groups: Sham, HF and HF/Tadalafil (5mg/day IP for more 4 weeks). Intracavernous pressure measurement (ICP) was used to evaluate erectile function in vivo. Response concentration curves were constructed to assess both vascular reactivity in response to phenylephrine (PE), acetylcholine and sodium nitroprusside (SNP), as well as the cavernosal muscle (CC) reactivity in response to PE and SNP. Electrical stimulation (EFS) were obtained to evaluate neurogenic contraction and nitrergic relaxation in CC rat.ResultsAfter 12 weeks, HF group presented both reduced of ejection and shortening fraction (p<0.05), as well present cardiac hypertrophy (P <0.05) when compared to the Sham group. Treatment with tadaladil restored the ejection and shortening fraction in the HF/Tadalafil (p<0.05), and reduced cardiac hypertrophy induced by HF. Moreover, HF animals presented an increase in the contractile vascular response mediated by PE when compared to Sham group (p<0.05), being this vascular hypercontractility restored by the tadalafil treatment (p<0.05). In addition, aorta of HF rats showed reduction of the ACh‐mediated relaxation (p<0.05) compared to the control, and this effect was restored by tadalafil treatment (p<0.05). Regarding erectile function, the data show that HF animals present a reduction of intracavernous pressure (p<0.05) compared to the Sham group, that was restored by tadalafil treatment (p<0.05). The contractile mechanism of CC, in response to PE and neurogenic electrical stimulation (p<0.05) were increased in HF rats, on the other side, the treatment with tadalafil improve the CC hypercontractility in these animals (p<0.05). In addition, tadalafil treatment also restored both SNP (p<0.05) and nitrergic (p<0.05) mediated relaxation in the CC of HF rats.ConclusionOur data show that the chronic treatment with tadalafil improved both vascular‐ and no‐vascular smooth muscle reactivity since exerting beneficial effects in the cardiovascular and erectile function in HF rats. Data suggesting that tadalafil acts is a multi‐therapeutic agent in HF rats.Support or Funding InformationFinancial suport: FAPESP: 2011/21095‐4 / CNPq: 423987/2016‐0This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

INTRODUCTIONPatients with heart failure (HF) display erectile dysfunction (ED). Currently a pharmacological option for the ED treatment are the phosphodiesterase (PDE) 5 inhibitors, however, these has no complete satisfactory response in all patients. The role of other PDEs to treat the ED remains poorly investigated. PDE‐9 specifically hydrolyzes cyclic‐GMP, and was detected in mice and human corpus cavernosum (CC) moreover, the PDE9 inhibitor selective (BAY 73‐6691) amplifies the NO‐cGMP‐mediated cavernosal responses, may be of therapeutic value for ED treatment associated with HF.OBJECTIVEThe aims of the present study were to characterize the effect of BAY 73‐6691, both on the contractile response of rats CC submitted to aortocaval fistula (ACF) model, as in the CC contractile response of rats with HF submitted to chronic treatment with tadalafil.METHODSMale Sprague‐Dawley rats (250g) were submitted to the ACF. After 48 hours, the animals were divided in SHAM and ACF groups (acute protocol). After 8 weeks, to validation of HF, the animals underwent to echocardiogram and were divided into 4 groups: SHAM and HF groups (0.9% saline solution, daily), and TADALAFIL and HF TADALAFIL groups (treated with Tadalafil 5 mg/daily), the treatment was maintained for 4 weeks (chronic protocol). Echocardiogram were used to evaluate the final cardiac function. In all protocols, cumulative concentration‐response curve to phenylephrine (PE; 10 nM‐100μM) and neurogenic contractile responses induced by electrical‐field stimulation (EFS; 1‐32 Hz) were obtained in cavernous smooth muscle, both in the presence or absence of BAY 73‐6691.RESULTSAfter 48 hours, both the neurogenic contraction as well contractile response to PE were increased in the ACF group when compared to the Sham group (p <0.05). However, BAY 73‐6691 restored adrenergic hypercontractility in the ACF group (p <0.05). After 12 weeks, there was an increase in LV mass and a decrease in ejection fraction in HF group when compared to the Sham group (p <0.05). However, in the HF Tadalafil group, the treatment was able to restore the ventricular function and decrease LV mass (p <0.05). Moreover, the neurogenic contraction and contractile response to PE in CC were increased in the HF group when compared to the Sham group (p <0.05) and the treatment with tadalafil restored adrenergic hypercontractility of CC in the HF Tadalafil group (p <0.05). In addition, the CC hypercontractility, observed in the HF group, in response to EFS and PE were reduced with the addition of BAY 73‐6691 (P<0.05). Moreover, BAY 73‐6691 shown an additive in the reduction of contractile mechanism in the rats CC with HF treated with tadalafil (p <0.05).CONCLUSIONBAY 73‐6691 reduces the adrenergic hypercontractility in the CC of ACF rat. Treatment with Tadalafil improve the cardiac function and restore the increased of contractile response of rat CC with HF. Moreover, BAY 73‐6691 (in vitro) promote additive effect associated with treatment of tadalafil and restore the adrenergic hypercontractility in the CC of rats with HF.Support or Funding InformationFAPESP ‐ Grant number: 2011/21095‐4This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.