Hypertension
Erectile dysfunction and hypertension are widely acknowledged to be associated, but there have been relatively few experimental investigations into the mechanisms. The animal model of hypertension most widely used to assess erectile function is the spontaneously hypertensive rat (SHR). A small number of investigations have also assessed the impact of secondary hypertension due to DOCA-salt treatment, aortoiliac balloon injury, experimental passive cigarette smoke inhalation, and increased alcohol consumption. In normotensive rats, these manipulations induced both hypertension and erectile dysfunction. However, there remains considerable work remaining, linking the hypertension with specific pathologic derangements of the erectile microanatomy, cellular physiology, and molecular biology. Viagra Australia shipping
Aging
The development of ED with aging was first identified in copulatory studies. Subsequent studies using other models of erectile function discussed above, indicates that the ED in aged rats is due to the loss of smooth muscle and endothelium, fibrosis and decreases in nitric oxide signaling. These findings are congruent with studies in aging men, indicating that the aged rat model may be a valuable tool in analyzing this particular form of ED.
Diabetes
Of all the models of ED, the streptozotocin induced diabetic rat is one of the most widely employed. This model shows a robust ED when compared with age-matched controls. An important finding is that nitric oxide signaling is decreased in diabetes, and after prolonged diabetes, this decrease of nitric oxide is irreversible, due to the loss of nitric oxide neurons as a result of oxidative stress and advanced glycosylation end products.
Other studies of diabetes-related ED use the genetically diabetic BB/WOR rat, which is insulin-dependent and ketotic prone form of type 1 diabetes. The BB/WOR rat exhibits severe neuropathy in somatic, sympathetic, and parasympathetic nerves without the compounding angiopathy associated with human diabetes. The copulatory behavioral testing and the study of sexual reflexes confirmed the severe neuropathy associated with ED in the BB/WOR rat. Additionally, these diabetic animals exhibit considerable decreases in penile reflexes, indicative of peripheral neuropathy, but did not show any impairment of the cavernosal nerve-mediated erectile response at 3–5 months of diabetes. Therefore, this animal model may be useful to distinguish between the role of neuropathy and vasculopathy on erectile function in diabetes. www.myviagrainaustralia.com get viagra now
A major research need is the development of robust and satisfactory models of Type 2 diabetes, as this is the most prevalent form of human disease and increasing with the ongoing obesity epidemic.