Penile constitutive nitric oxide synthase expression in rats exposed to unpredictable chronic mild stress: role of inflammation.

Chronic psychological stress cause erectile dysfunction (ED). Considering recent evidence that tumor necrosis factor-α (TNF-α) levels are increased in serum of patients with ED, the present study investigated the effects of infliximab (a TNF-α blocker) on endothelial nitric oxide synthase (eNOS) and neuronal NOS (nNOS) immunoreactivity of rat penile corpus cavernosum in unpredictable chronic mild stress (UCMS). Male adult rats were randomly divided into three groups (n=8 per group): Control, UCMS and UCMS+infliximab. Control and UCMS groups received physiological saline, UCMS+infliximab group received infliximab (5 mg kg-1 per week, intraperitoneally) during 8 weeks of UCMS. UCMS and UCMS+infliximab groups were subjected to different types of stressors, which were randomly applied four to five times during this time period. After 8 weeks, penile eNOS and nNOS expressions were determined immunohistochemically. In UCMS group, nNOS and eNOS immunoreactivity was found to be decreased in penile corpus cavernosum compared with the control group. Whereas in infliximab treatment group eNOS and nNOS immunoreactivity increased compared with the UCMS group. These findings support that UCMS decreases penile constitutive NOS expression via TNF-α, which may contribute to the development of ED. Blockage of TNF-α actions may represent an alternative therapeutic approach for ED in chronic psychological stress.

Effect of intratympanic dexamethasone, memantine and piracetam on cellular apoptosis due to cisplatin ototoxicity.

OBJECTIVE: This study aimed to contribute to the literature on the prevention and treatment of ototoxicity due to various drugs and chemicals. MATERIAL AND METHODS: This study compared the histological effects of intratympanic dexamethasone, memantine and piracetam on cellular apoptosis due to cisplatin ototoxicity, in 36 rats. RESULTS: Dexamethasone and memantine had significant effects on the stria vascularis, organ of Corti and spiral ganglion (p < 0.05). Although piracetam decreased the apoptosis rate, this effect was not statistically significant (p > 0.05). CONCLUSION: Dexamethasone and memantine were found superior to piracetam in reducing apoptosis due to cisplatin ototoxicity. Further studies of this subject are needed, incorporating electron microscopy and auditory brainstem response testing.

Effects of chronic low- and high-dose ethanol intake on the nitrergic relaxations of corpus cavernosum and penile nitric oxide synthase in the rabbit.

Epidemiological evidence showed that chronic ethanol consumption is a major risk factor in the development of impotence. The present study investigated the effects of carbachol-, electrical field stimulation (EFS)-, sodium nitroprusside (SNP)- and papaverine-induced relaxant responses in the isolated corpus cavernosum tissues from rabbits submitted to an 12-week course of chronic low (5% v/v) or high ethanol intake (30% v/v). Increased carbachol- and EFS-induced relaxant responses but not SNP and papaverine, were observed in low ethanol-fed rabbits compared with controls. However, impaired carbachol- and EFS-induced relaxant responses were observed in high ethanol-fed rabbits compared with control rabbits. There were no significant differences in SNP- and papaverine-induced relaxant responses between control and high ethanol-fed rabbits. In addition, decreased neuronal nitric oxide synthase (nNOS) and endothelial NOS (eNOS) immunoreactivity in penile tissue were found in high ethanol-fed rabbits, but increased the immunoreactivity in low ethanol-fed group, compared with control group. These results suggest that alterations in nitric oxide (NO) production within the cavernous tissue in the high ethanol-fed rabbits are, at least in part, responsible for the erectile dysfunction.

Changes in the neurogenic and endothelium-dependent relaxant responses of rabbit corpus cavernosum smooth muscle after cavernous nerve neurotomy.

The present study was conducted to investigate the reactivity of the corpus cavernosum smooth muscle after unilateral cavernous nerve neurotomy in rabbits. Rabbits (18) were randomly divided into two groups: sham-operated (n = 9) and those subjected to unilateral neurotomy of a 5-mm segment of the cavernous nerve (n = 9). The reactivity of the corpus cavernosum tissue from the neurotomized and sham groups was studied in organ chambers at 4 weeks postoperation. In the neurotomized group, endothelium-dependent relaxation of the corpus cavernosum smooth muscle to carbachol was significantly increased when compared to the sham group. In addition, the sensitivity (i.e., pD(2)) of neurotomized strips to carbachol was also increased when compared to controls. Electrical field stimulation-induced neurogenic relaxation was significantly reduced in the neurotomized group. Relaxation to the nitric oxide (NO) donor sodium nitroprusside and to papaverine was similar in the cavernosal tissue of both groups. There was no change in agonist potency. Furthermore, neurotomy had no effect on KCl-induced contractile responses. When tissue contraction was induced with phenylephrine to study relaxation to various stimuli, the tension induced was similar in the neurotomized and the sham control groups. We conclude that unilateral, chronic cavernous nerve neurotomy causes significant functional changes to the penile erectile tissue of rabbits, which may contribute to the development of impotence.

Aerobic capacities and blood pressure responses of five different groups in North Sumatra and Aceh at different workloads.

In five different groups consisting of athletes (TPG), high school students, men and women (HS), rural group (Arun), and a professional football group (Galatama), the VO2max was determined indirectly, using the cycle ergometer exercise test and Astrand's nomogram. Systolic and diastolic blood pressure was determined using a sphygnomanometer and measured after steady state was reached at each load. The aerobic capacities of the group below 20 years differ significantly between the TPG and all the other groups compared (P less than 0.01). Between the other groups there is a difference in VO2max, though significant differences were only found between the HS (men), Arun group and the HS (women) (P less than 0.01). In the group above 20 years the TPG group have the highest VO2max, and the differences when compared with the HS (men) and Arun groups were significant (P less than 0.01). In the Arun group above 30 years, though a lower values was found in the older age group, significant differences in VO2max were only found between the 30-39 years and the 40-49 years age group (P less than 0.01). Blood pressure responses to different workloads successfully confirmed the results reported by Astrand and Rodahl (1970) and Barnard et al. (1973), but no consistent relationship was found between aerobic capacities and systolic blood pressures.

Maximal working capacity of two professional groups in North Sumatra (Indonesia).

Two groups of male students from the medical school and sports academy and two groups of tricycle drivers performed maximally on two occasions on a brake type ergometer against a load sustainable between 2-6 min according to Tornvall. In the students the difference in work performance between the medical and sports academy students, maybe due to difference in their training condition, shown by the increment and decrement of pulse rate respectively on starting and stopping the test, since all their anthropometric measurements are the same. A comparison of the maximum working capacity between the tricycle drivers to study the effect of a potion called "jamu" showed no difference (N1 = 11, X1 = 1523 m . kp . min-1, N2 = 10, X2 = 1,664 m . kp . min-1, p greater than 0.05). The maximum working capacity of the tricycle drivers was found to be the same as the students from the sports academy (N1 = 21, X1 = 1,587 m. kp. min-1, N2 = 9, X2 = 1,524 m . kp . min-1, p greater than 0.05). Maximal heart rate between the medical students and the sports academy students differ significantly (N1 = 22, X1 = 186 min-1, N2 = 9, X2 = 175 min-1, p less than 0.01), but not significantly different between the sports academy students and the beca drivers (N1 = 9, X1 = 175 min-1, N2 = 21, X2 = 180 min-1, p greater than 0.05).