5-hydroxy-L-tryptophan Suppressed Food Intake in Rats Despite an Increase in the Arcuate NPY Expression

This study was conducted to define the underlying mechanism of hypophagia induced by increased central serotonergic action. Rats received 3 daily injections of 5-hydroxy-L-tryptophan (5-HTP), a serotonin precursor, at a dose of 100 mg/kg/10 ml saline at 1 h before lights off. A significant suppression in food intake was observed shortly after the 5-HTP injection and persisted during 3 daily 5-HTP injections. Neuropeptide Y (NPY) expression in the arcuate nucleus increased after 3 days of 5-HTP treatment, as high as in the pair-fed group. Immunoreactivity of phosphorylated extracellular signal-regulated protein kinase (pERK1/2) in the hypothalamic paraventricular nucleus (PVN) was increased markedly by 3 days of 5-HTP treatment, but not by 3 days of pair-fed. mRNA expression levels of serotonin reuptake transporter (5-HTT) was increased in the dorsal raphe nucleus of the 5-HTP treated rats, but not in the pair-fed group. Results suggest that increased pERK1/2 in the PVN of 5-HTP injected rats may be a part of serotonergic anorectic signaling, perhaps blunting the orectic action of NPY; i.e., 5-HTP injected rats showed hypophagia despite of increased NPY expression in the arcuate nucleus.

Serotonin transporter mRNA expression in the dorsal raphe nucleus of a tumor bearing mouse

This study was conducted to determine if an oral squamous cell carcinoma alters mRNA expression of serotonin transporter (5-HTT) in the central nervous system. KB cell line derived from a human oral squamous cell carcinoma was inoculated into nude mice, and mRNA expression level of 5-HTT in the dorsal raphe nucleus (DRN) was examined by in situ hybridization when the tumor mass reached to -10% of total body weight. Plasma leptin levels were determined by radioimmunoassay method using a commercial kit. 5-HTT mRNA level was significantly decreased in the DRN of tumor bearing mice, compared to the age-matching non-tumor control. Plasma leptin level decreased concomitantly in tumor bearing mice. These results suggest that oral carcinoma may suppress 5-HTT gene expression in the central nervous system, perhaps in relation with decreased plasma leptin level.

Central N omega-nitro-L-arginine Methyl Ester Does not Influence Lithium-induced c-Fos and Conditioned Taste Aversion

LiCl at doses sufficient to induce conditioned taste aversion (CTA) causes c-Fos expression in the brain regions implicated in CTA formation. It has been reported that nitric oxide (NO) may play a role in CTA learning and LiCl increases both the synthesis and activity of NO synthase (NOS) in the brain. In this study, we examined the effect of central N omega-nitro-L- arginine methyl ester (L-NAME) on the brain c-Fos expression and CTA learning induced by lithium in rats. In the results, intracerebroventricular L-NAME given prior to lithium did not change either the lithium-induced CTA or c-Fos in the relevant brain regions. This suggests that the brain NO system may not be involved in the neuronal activation during lithium-induced CTA formation.

Improved protocol for schwann cell isolation and proliferation from rat dorsal root ganglia in vitro

Results of microscopic discectomy in lumbar disc herniation: A 5-years follow up / 대한척추외과학회지

PURPOSE: This study was performed in an attempt to determine if there was any clnical benefit of microdiscectomy(MD) over standard discectomy(SD). They were all followed up by an impartial observer at 1 year and 5 years. MATERIALS AND METHODS: All patients were operated on by the same surgeon by either method. We evaluate retrospectively 30 cases of microdiscectomy and 30 cases of standard discectomy using data derived from a questionnaire and chart review from January 1. 1988 to December 31. 1993. The operative results were analysed with Kim's criteria and that clinical results were statistically used to Paired two-tailed T test. RESULTS: 1) Mean operating time was about 117minutes in the standard discectomy, while 98 minutes in the microdiscectomy. 2) Mean time to return to work was about 9.6 weeks in the standard discectomy, while 5.9 weeks in the microdiscectomy, 3) In initial and 1 year follow up, microdiscectomy was superior to the standard discectomy but in 5 years follow up, the two procedures have a similar outcome. CONCLUSION: The advantage of microdiscectomy was more safe than standard discectomy, because it was magnified vision and brilliant illumination, precise identification of structures in deep fields(including nerve root and its related structures), a marked advantage to dissect the adhere nerve root to its surroundings structures, its capacity to preserve the integrity of normal tissue, and meticulous hemostasis. From this analysis, we conclude that microdiscetomy represents a small but significant refinement of standard discectomy