The molecular mechanism of nitric oxide synthase (NOS)-containing nerve regeneration is still unknown. It is believed that growth factors are involved in this phenomenon. We investigated the change of NOS containing nerve ®bers and the mRNA expression of insulin like growth factor (IGF)-I, nerve growth factor (NGF), transforming growth factor (TGF)-a, TGF-b 1 , TGF-b 2 , TGF-b 3 , vascular endothelial growth factor (VEGF), endothelial NOS (eNOS) and neuronal NOS (nNOS) on the penis after cavernous nerve neurotomy in rats.Male rats were divided into four groups: (1) sham operation (n 14); (2) unilateral neurotomy of a 5 mm segment of the cavernous nerve (n 21); (3) unilateral neurotomy with growth hormone (n 14); and (4) bilateral neurotomy (n 21). Electrostimulation of the intact cavernous nerve or pelvic ganglion were performed at one, three and six months. Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining and immunohistochemistry were used to identify NOS in the penis. The gene expression for growth factors, eNOS and nNOS were investigated in corporal tissue by reverse transcriptase-polymerase chain reaction (RT-PCR).One month after neurotomy, both unilateral and bilateral neurotomy groups showed signi®cant decreases in NOS-containing nerve ®bers on the dorsal and intracavernosal nerves on the side of neurotomy. Signi®cantly lower mRNA expression of nNOS, IGF-I and TGF-b 2 , higher mRNA expression of eNOS and VEGF 189 were shown in these groups. At three months, the number of NOS-containing nerve ®bers in the unilateral neurotomy group increased only slightly, while the GH-treated group showed a signi®cant increase. At six months, those in the intracavernosal nerve only increased in a signi®cant amount (P`0.0001), however mRNA expression of nNOS, IGF-I and TGF-b 2 showed a signi®cant increase as early as at three months. After bilateral neurotomy, the NOS-positive nerve ®bers in the dorsal and intracavernosal nerve were signi®cantly decreased at one month and remained so at six months; no erectile response could be elicited by pelvic ganglion stimulation. In the unilateral neurotomy group at six months, more NOS-positive neurons in the pelvic ganglia were found on the intact side than on the side of the neurotomy (P`0.003), indicating that the regeneration derived from pelvic ganglion neurons on the intact side. Furthermore, electrostimulation in the unilateral neurotomy group revealed a greater maximal intracavernosal pressure and a shorter latency period at six months than at one month (P`0.014, P`0.001, respectively).These data suggest that IGF-I and TGF-b 2 may play a key role in the regeneration of nNOScontaining nerve ®bers in the dorsal and intracavernosal nerves, and eNOS increases temporarily in the intracavernous involving VEGF 189 after unilateral cavernous nerve injury.
Nitric oxide synthase (NOS) containing nerve regeneration can be seen six months after unilateral cavernous nerve neurotomy in rats. However its molecular mechanism is still unknown. It is believed that growth factors are involved in this phenomenon. In this study we investigated the change of NOS containing nerve ®bers and the RNA expression of insulin like growth factor (IGF)-I, nerve growth factor (NGF), transforming growth factor (TGF)-a, TGF-b 1 , TGF-b 2 . TGF-b 3 and NOS on the penis after cavernous nerve neurotomy in rats.Male rats were divided into three groups: (1) sham operation (N 10); (2) unilateral neurotomy of a 5 mm segment of the cavernous nerve (N 15); and (3) bilateral neurotomy (n 15). Electrostimulation of the intact cavernous nerve or pelvic ganglion was performed at one, three and six months. Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining was used to identify NOS in the penile nerve ®bers. The gene expression for growth factors and bNOS was investigated in corporal tissue by reverse transcriptase-polymerase chain reaction (RT-PCR) using speci®c oligonucleotide primers.One month after neurotomy, both unilateral and bilateral neurotomy groups showed a signi®cant decrease in NOS-containing nerve ®bers on the dorsal and intracavernosal nerves on the side of neurotomy, and a signi®cantly lower mRNA expression of bNOS, IGF-I and TGF-b 2 . At three months, the number of NOS-containing nerve ®bers in the unilateral neurotomy group increased only slightly but at six months those in the intracavernosal nerve increased in a signi®cant amount (P`0.0001), however mRNA expression of bNOS, IGF-I and TGF-b 2 showed a signi®cant increase as early as at three months. After bilateral neurotomy, the NOS-positive nerve ®bers in the dorsal and intracavernosal nerve were signi®cantly decreased at one month and remained so at six months; no erectile response could be elicited by pelvic ganglion stimulation. In the unilateral neurotomy group at six months, more NOS-positive neurons in the pelvic ganglia were found on the intact side than on the side of the neurotomy (P`0.003), indicating that the regeneration derives from pelvic ganglion neurons on the intact side. Furthermore, electrostimulation in the unilateral neurotomy group revealed a greater maximal intracavernosal pressure and a shorter latency period at six months than at one month (P`0.014, P`0.001, respectively).These data suggest that IGF-I and TGF-b 2 may play a key role in regeneration of NOS-containing nerve ®bers in the dorsal and intracavernosal nerves after unilateral cavernous nerve injury.
This study was aimed to identify characteristics of ED patients who discontinued PDE5i despite successful intercourse. Data were collected using a questionnaire from 34 urologic clinics regardless of the effect (success or failure) of PDE5i treatment by visiting the clinics (717), e-mail (64) or post (101) for 882 ED patients who had previously taken any kind of PDE5i on demand four or more times. Discontinuation of PDE5i was defined if the patient had never taken PDE5i for the previous 1 year despite successful intercourse. Of the 882 patients, 485 were included in the final analysis. Difference in the socio-demographic, ED- and partner-related data between the continuation and discontinuation group and factors influencing discontinuation of the PDE5i were analyzed. Among 485 respondents (mean age, 53.6), 116 (23.9%) had discontinued PDE5i use despite successful intercourse. Most common reasons for the discontinuation were ‘reluctant medication-dependent intercourse' (31.0%), ‘spontaneous recovery of erectile function without further treatment' (30.2%), and ‘high cost' (26.7%). In multiple logistic regression analysis, independent factors influencing discontinuation of the drug were cause of ED (psychogenic), short duration of ED, low education (⩽ middle school), and religion (Catholic). In partner-related compliance, only partner's religion (Catholic) was a significant factor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.