Effect of testosterone and frequent low-dose sildenafil/tadalafil on cavernous tissue oxidative stress of aged diabetic rats.

This study aimed to assess the effect of testosterone (T) administration and chronic low-dose sildenafil/tadalafil on cavernous tissue oxidative stress (OS) of aged diabetic rats. In all, 140 Sprague-Dawley aged rats were subdivided into the following: controls; streptozotocin (STZ)-induced diabetic rats; diabetic rats injected with T every 4 weeks; diabetic rats on sildenafil orally daily; diabetic rats on T and daily sildenafil; diabetic rats on tadalafil orally every other day; diabetic rats on T and tadalafil; diabetic rats on alternate sildenafil/tadalafil; and diabetic rats on alternate sildenafil/tadalafil with T. After 12 weeks, the rats were euthanised where in dissected cavernous tissues malondialdehyde (MAD), glutathione peroxidase (GPx) and cGMP (cyclic guanosine monophosphate) were estimated. Compared with controls, aged diabetic rats demonstrated significant increase in cavernous tissue MDA and significant decrease in GPx and cGMP where diabetic rats injected with T had marked improvement of these parameters. Diabetic rats on sildenafil, tadalafil or alternate sildenafil/tadalafil demonstrated significant increased cavernous tissue GPx, cGMP and decreased cavernous MDA that was further improved when supplemented with T. It is concluded that frequent low-dose use of sildenafil and/or tadalafil supplemented with T has a marked impact on ameliorating cavernous OS in aged diabetic rats.

Testosterone and chronic sildenafil/tadalafil anti-apoptotic role in aged diabetic rats.

This work aimed to assess the cavernous anti-apoptotic role of using chronic low-dose sildenafil/tadalafil with and without testosterone (T) in aged diabetic rats. In all, 140 Sprague-Dawley aged rats were divided into the following groups: controls; induced diabetic rats; diabetic rats that received intramuscular depot T once every 4 weeks; diabetic rats on sildenafil 2 mg kg(-1) orally daily; diabetic rats on T and daily sildenafil; diabetic rats on tadalafil 0.45 mg kg(-1) orally every other day; diabetic rats on every-other-day tadalafil and T; diabetic rats on alternate sildenafil and tadalafil; and diabetic rats on alternate sildenafil, tadalafil and T. After 12 weeks, Bax (apoptotic factor), Bcl(2) (B-cell lymphoma 2; anti-apoptotic factor), cGMP (cyclic guanosine monophosphate) were estimated in their cavernous tissues. Compared with the controls, aged diabetic rats showed significant increased cavernous tissue Bax and significant decreased Bcl(2), in which diabetic rats injected with T showed the reverse compared with the diabetic rats. Diabetic rats on sildenafil or tadalafil showed significant increased cavernous Bcl(2) and decreased Bax with upgraded Bcl(2)/Bax ratio that was improved being on T. Diabetic rats on alternate sildenafil/tadalafil with or without T showed further significant increased cavernous tissue Bcl(2) with upgraded Bcl(2)/Bax ratio. It is concluded that frequent low-dose use of sildenafil and/or tadalafil combined with T would be predicted to have a pronounced anti-apoptotic cavernous tissue effect on the cavernous tissues of aged diabetic rats.

Continuous positive airway pressure in the prophylaxis of the adult respiratory distress syndrome.

After an operation upon the abdomen, certain patients have a high risk of developing acute respiratory failure or the adult respiratory distress syndrome. These patients at high risk have been mechanically ventilated during the postoperative period in an attempt to prevent the onset of respiratory insufficiency. As a method of prophylaxis, continuous positive airway pressure has the advantages of increasing the functional residual capacity with minimal effects on the cardiac output, low potential for barotrauma and simplicity of equipment. Alternate patients at risk following an operation on the upper part of the abdomen were placed on 8 centimeters of water continuous positive airway pressure for the first 24 hours postoperatively. Fifty-six controls and 56 patients receiving continuous positive airway pressure were studied. In ten controls, adult respiratory distress syndrome developed, and three died in respiratory failure. Only one of the group receiving continuous positive airway pressure met standard criteria for the diagnosis of adult respiratory distress syndrome. In addition, in 25 patients serving as controls, respiratory complications other than adult respiratory distress syndrome developed compared with the development in only 11 receiving continuous positive airway pressure9

Continuous positive airway pressure in the prophylaxis of the adult respiratory distress syndrome (ARDS).

Alternate patients believed to be at risk for developing ARDS were placed on CPAP for the first twenty-four hours post upper abdominal surgery. Ten of the 58 controls developed ARDS, requiring prolonged mechanical ventilation with a 30% mortality rate. Only one of the 59 CPAP patients developed evidence of ARDS. This patient, however, is believed to have had fluid overload, and responded quickly to diuretics and was extubated within two days. Thus, prophylactic CPAP has greatly decreased our postoperative morbidity and mortality related to respiratory causes.