The Action Mechanism of Growth Hormone on Regeneration of Nitiric Oxide Synthase(NOS)-containing Nerves after Cavernous Neurotomy in the Rat.
- Author:
Gyung Woo JUNG
1
;
Jong Young KWAK
;
Joong Keun KIM
;
Jin Han YOON
Author Information
1. Department of Urology, Dong-A University, College of Medicine, Pusan, Korea.
- Publication Type:Original Article
- Keywords:
Growth factor;
Neurotomy;
Growth hormone;
nNOS
- MeSH:
Animals;
DNA Primers;
Gene Expression;
Growth Hormone*;
Humans;
Insulin;
Insulin-Like Growth Factor I;
Latency Period (Psychology);
Male;
NAD;
Nerve Fibers;
Nerve Regeneration;
Nitric Oxide;
Rats*;
Regeneration*;
RNA, Messenger
- From:Korean Journal of Urology
1999;40(8):1043-1050
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: As growth hormone was reported to improve cavernosal nerve regeneration, we studied the action mechanism of growth hormone(GH) on the regeneration of nitric oxide synthase(NOS)-containing penile nerves after unilateral cavernous nerve neurotomy in rats. MATERIALS AND METHODS: Male rats were divided into three groups: sham operation(n=10); unilateral neurotomy of a 5mm segment of the cavernous nerve(n=10) and unilateral neurotomy with GH injection(n=10). Electrostimulation of the intact cavernous nerve was performed at 1 and 3 months after operation. Nicotinamide adenine dinucleotide phosphate(NADPH) diaphorase staining was used to identify nNOS in penile nerve fibers of the mid-shaft segment. The gene expression for nNOS, insulin like growth factor(IGF)-I and nerve growth factor(NGF) were investigated in corporal tissue by reverse transcriptase-polymerase chain reaction(RT-PCR) using specific oligonucleotide primers. RESULTS: Electrostimulation in the GH-treated group revealed a greater maximal intracavernosal pressure and a shorter latency period than in those given neurotomy alone at 3 months after operation. One month after unilateral neurotomy, both neurotomy alone and the GH-treated groups showed a significant decrease in NOS-containing nerve fibers in the dorsal and intracavernosal nerves on the side of neurotomy, however mRNA expression of nNOS and IGF-I showed a significant increase in GH-treated group. At 3 months, the number of NOS-containing nerve fibers in the neurotomy alone group did not increase while the GH-treated group showed a significant increase. CONCLUSIONS: These results show that GH significantly enhances the regeneration of NOS-containing fibers in the dorsal and intracavernosal nerves after unilateral cavernous nerve injury via IGF-I.
