1.Changes in Hypothalamic-pituitary-growth Hormone (GH) Axis by Fasting: Study on the Differences between Male and Female Rats.
Sookjin SOHN ; Mina LEE ; Seungjoon PARK
Journal of Korean Society of Endocrinology 2002;17(4):473-485
BACKGROUND: Fasting has a profound impact on GH synthesis, and is released in all mammalian species that have been studied. The male rat has long been used as a model to determine the mechanism on how fasting mediates these changes. However, many aspects of GH synthesis, release and function are known to be gender-dependent. This study was conducted in order to determine if changes in the GH-axis, in response to fasting, differs between the sexes. METHODS: Male and female rats (8~9 weeks; n=5/group) were fasted for 72h, or supplied food ad libitum. The mean circulating serum GH and IGF-I concentrations were measured by radioimmunoassay. The levels of hypothalamic GH-releasing hormone (GHRH), somatostatin (SRIF), neuropeptide Y (NPY) and pituitary GH mRNA were measured using an RNase protection assay. The levels of pituitary GHRH receptor (GHRH-R), GH secretagogue (GHS) receptor (GHS-R) and SRIF receptor (sst1-5) mRNA were measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Fasting resulted in a comparable weight loss in both the males and the females, (18.0+/-0.9%) and (17.0 0.8%), respectively. In the fasted males, there was a characteristic decrease in the serum GH (98 60 vs. 7 4 ng/mL) and IGF-I (367 35 vs 152 12 ng/mL), associated with a decrease in the hypothalamic GHRH, and an increase in the NPY mRNA, levels of 52 6% and 138 6%, respectively, compared to those of the fed controls (p<0.05). In spite of the reduction in the GHRH, fasting did not alter the levels of the pituitary GH mRNA, and in fact increased the expression of the pituitary receptors, GHRH-R and GHS-R, to 185 15 and 169 25%, respectively, to those of the fed controls. In contrast to the positive impact of fasting on the GH-stimulatory receptors, fasting led to a dramatic decrease in the expressions of the somatostatin receptor subtypes, sst2 (29+/-5% of Fed) and sst4 (60+/-7% of Fed). Fasting had comparable effects on the GH-axis of the female rats, with two notable exceptions; first, fasting did not suppress the mean circulating GH levels (16 3 vs. 38 28 ng/mL) and second, did not alter the sst2 and sst4 expressions. CONCLUSION: These results corroborate the other reports regarding the effects of fasting on the expressions of hypothalamic neuropeptides, pituitary GHRH-R and sst2, in male rats. This is the first report demonstrating that fasting stimulates the expression of pituitary GHS-R in both sexes. This is of great interest given the fact that ghrelin, the putative GHS-R ligand, is also elevated by fasting. We propose that the upregulation of both ghrelin and GHS-R may play important roles in increasing the sensitivity of the pituitary to GHRH, in that these GH-stimulatory systems work synergistically. These changes may compensate for the fasting-induced suppression of hypothalamic GHRH input. We might speculate that such compensatory mechanisms are dominant in the female rat, in that circulating GH levels are not suppressed by fasting.
Animals
;
Axis, Cervical Vertebra*
;
Fasting*
;
Female*
;
Ghrelin
;
Growth Hormone
;
Humans
;
Hypothalamus
;
Insulin-Like Growth Factor I
;
Male*
;
Neuropeptide Y
;
Neuropeptides
;
Radioimmunoassay
;
Rats*
;
Receptors, Somatostatin
;
Ribonucleases
;
RNA, Messenger
;
Somatostatin
;
Up-Regulation
;
Weight Loss
2.Expression of nitric oxide synthase isoforms in the porcine ovary during follicular development.
Heechul KIM ; Changjong MOON ; Meejung AHN ; Yongduk LEE ; Hwanglyong KIM ; Seungjoon KIM ; Taeyoung HA ; Youngheun JEE ; Taekyun SHIN
Journal of Veterinary Science 2005;6(2):97-101
The expression of nitric oxide synthase (NOS) isoforms in the ovaries of pigs was examined to study the involvement of nitric oxide, a product of NOS activity, in the function of the ovary. Western blot analysis detected three types of NOS in the ovary, including constitutive neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS); eNOS immunoreactivity was more intense compared with that of iNOS or nNOS. Immunohistochemical studies demonstrated the presence of nNOS and eNOS in the surface epithelium, stroma, oocytes, thecal cells, and endothelial cells of blood vessels. Positive immunoreactions for nNOS and iNOS were detected in the granulosa cells from multilaminar and antral follicles, but not in those of unilaminar follicles. iNOS was detected in the surface epithelium, oocytes, and theca of multilaminar and antral follicles. Taking all of the findings into consideration, the observed differential expression of the three NOS isoforms in the ovary suggests a role for nitric oxide in modulating reproduction in pigs.
Animals
;
Blotting, Western/veterinary
;
Female
;
Immunohistochemistry/veterinary
;
Nerve Tissue Proteins/*biosynthesis
;
Nitric Oxide/metabolism
;
Nitric Oxide Synthase/*biosynthesis
;
Nitric Oxide Synthase Type I
;
Nitric Oxide Synthase Type II
;
Nitric Oxide Synthase Type III
;
Ovarian Follicle/*enzymology/growth&development
;
Swine/*physiology
3.Somatostatin Receptor.
Eunhee KIM ; Sookjin SOHN ; Mina LEE ; Heesoon PARK ; Jeechang JUNG ; Seungjoon PARK
Journal of Korean Society of Endocrinology 2003;18(4):342-355
No abstract available.
Receptors, Somatostatin*
;
Somatostatin*
4.Relation Between Horizontal Saccade Test and Anti-Compensatory Saccade in the Suppression Head Impulse Test Paradigm
Han Cheol LEE ; Seungjoon YANG ; Sung Huhn KIM ; Seong Hoon BAE
Korean Journal of Otolaryngology - Head and Neck Surgery 2024;67(6):322-327
Background and Objectives:
There is limited study reported on the relationship between horizontal saccades and anti-compensatory saccades (ACS) in the suppression head impulse paradigm (SHIMP). We investigated the relationship between horizontal saccades and ACS in SHIMP in individuals with normal vestibular function and determined the correlation between the associated factors.Subjects and Method Medical records of 79 patients with normal vestibular function and brain magnetic resonance images were retrospectively reviewed.
Results:
ACS and horizontal saccades results were strongly correlated with velocity (R= 0.345, p<0.001) and latency (R=0.547, p<0.001). The latency of ACS was significantly shorter (p<0.001) than that of horizontal saccades. The velocity of ACS was negatively correlated with the latencies of ACS (R=-0.318, p<0.001) and horizontal saccades (R=-0.322, p<0.001). Bilateral ACS latency (R=0.384 and 0.471 in right and left, p<0.001 in both side) and left side ACS velocity (R=-0.263, p=0.019) were significantly affected by age.
Conclusion
ACS in the SHIMP was strongly correlated with horizontal saccades. However, the latency of ACS was shorter than that of horizontal saccades. Therefore, patient age and results of the horizontal saccades tests should be considered while interpreting the ACS velocity, which reflects vestibulo-ocular reflex function in patients with vestibulopathy.
5.Isolation and characterization of Korean porcine deltacoronavirus strain KNU16-07
Guehwan JANG ; Seong Hee KIM ; Yoo Jin LEE ; Seungjoon KIM ; Du Sik LEE ; Kyoung Ki LEE ; Changhee LEE
Journal of Veterinary Science 2018;19(4):577-581
Porcine deltacoronavirus (PDCoV) has emerged in several pig-raising countries and has been a causative pathogen associated with diarrheal diseases in South Korea since 2014. In the present study, we were able to isolate and cultivate a Korean PDCoV strain (KNU16-07) in cell culture and investigate its pathogenicity. PDCoV-inoculated piglets showed watery diarrhea accompanied by acute enteritis in the natural host. Sequencing analysis demonstrated the genetic stability of KNU16-07 for at least thirty serial passages.
Cell Culture Techniques
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Diarrhea
;
Enteritis
;
Korea
;
Serial Passage
;
Virulence
6.The Role of Genetic Polymorphism of Cytochrome P450 2E1 in Bladder Cancer in Korea.
Jiyeob CHOI ; Seungjoon LEE ; Kyoungmu LEE ; Inmi CHOI ; Youngju LEE ; Hyungjune IM ; Sang Yun LEE ; Kijung YOON ; Sooung KIM ; Moonsoo PARK ; Hanyong CHOI ; Whang CHOI ; Keunyoung YOO ; Soohun CHO ; Daehee KANG
Korean Journal of Epidemiology 2000;22(1):59-67
Although the association of genetic polymorphisms in glutathione S-transferase(GST) and N-acetyltransferase(NAT) with bladder cancer has been reported, limited numbers of studies have been indicated the association of CYP2E1 with bladder cancer, particularly in Asian population. A hospital based case-control study was conducted in South Korean, consisting of 232 histologically confirmed prevalent bladder cancer cases and 165 controls to evaluate the association between genetic polymorphisms of CYP2E1(RsaI) and development of bladder cancer. The frequency of CYP2E1(RsaI) c1/c1 genotype in bladder cancer cases was higher than in controls; 114 of 201(56.7%) vs. 62 of 146(42.5%). Men with CYP2E1(RsaI) c1/c1 genotype had increased risk of development of bladder cancer compared to men with at least one c2 allele(OR=1.7, 95% CI=1.1-2.7). The bladder cancer risk increased as the number of c1 allele increased(p for trend=0.005). The risk increased as the amount of smoking increased(p for trend=0.009). When data were analyzed for the interaction between smoking and CYP2E1 genetic polymorphisms, smokers with c1/c1 genotype have 2.5 greater risk in development of bladder cancer(95% CI=1.0-6.2) compared to nonsmokers with c2 allele(p for interaction=0.008). Our findings suggest that the interaction between genetic polymorphisms of CYP 2E1 (RsaI, c1/c1) and smoking may play an important role for development of bladder cancer among Koreans.
Alleles
;
Asian Continental Ancestry Group
;
Case-Control Studies
;
Cytochrome P-450 CYP2E1*
;
Cytochrome P-450 Enzyme System*
;
Cytochromes*
;
Genotype
;
Glutathione
;
Humans
;
Korea*
;
Male
;
Polymorphism, Genetic*
;
Smoke
;
Smoking
;
Urinary Bladder Neoplasms*
;
Urinary Bladder*
7.The expression and cellular localization of phospholipase D isozymes in the developing mouse testis.
Seungjoon KIM ; Heechul KIM ; Yongduk LEE ; Jin Won HYUN ; Young Ho LEE ; Min Kyoung SHIN ; Do Sik MIN ; Taekyun SHIN
Journal of Veterinary Science 2007;8(3):209-212
To examine the involvement of phospholipase D (PLD)isozymes in postnatal testis development, the expression ofPLD1 and PLD2 was examined in the mouse testis atpostnatal weeks 1, 2, 4, and 8 using Western blot analysisand immunohistochemistry. The expression of both PLD1and PLD2 increased gradually with development frompostnatal week 1 to 8. Immunohistochemically, PLDimmunoreactivity was detected in some germ cells in thetestis and interstitial Leydig cells at postnatal week 1.PLD was mainly detected in the spermatocytes andresidual bodies of spermatids in the testis after 8 weeksafter birth. The intense immunostaining of PLD in Leydigcells remained unchanged by postnatal week 8. Thesefindings suggest that PLD isozymes are involved in thespermatogenesis of the mouse testis.
Animals
;
Blotting, Western
;
Female
;
Immunohistochemistry
;
Isoenzymes
;
Male
;
Mice
;
Mice, Inbred BALB C
;
Phospholipase D/biosynthesis/*metabolism
;
Spermatogenesis/physiology
;
Testis/*enzymology/growth & development
8.Developing veterinary basic clinical skill items based on Korean Veterinary Entrustable Professional Activity
Kichang LEE ; Heungshik S. LEE ; Seong Mok JEONG ; Jongil KANG ; Seungjoon KIM ; Jin-Young CHUNG ; Sang-Soep NAHM ; Pan Dong RYU
Journal of Veterinary Science 2024;25(5):e71-
Objective:
This study aimed to establish the basic veterinary clinical skills required to ensure graduates of Korean veterinary universities have the day-one competency to independently perform their professional duties.
Methods:
The Education Committee of the Korean Association of Veterinary Medical Colleges, composed of veterinary school professors and an experienced veterinarian in the clinic, reviewed domestic and international veterinary education-related materials to define basic clinical skills.
Results:
The Korean Veterinarian Entrustable Professional Activities (KVEPA) was introduced, followed by the subsequent development of 54 essential clinical skills based on the KVEPA.
Conclusions
and Relevance: The veterinary basic clinical skills established through this study can be used as a specific guide for clinical education in Korean veterinary school, and is expected to play an important role in meeting the needs of the educational sector of the veterinary education accreditation standards.
9.Developing veterinary basic clinical skill items based on Korean Veterinary Entrustable Professional Activity
Kichang LEE ; Heungshik S. LEE ; Seong Mok JEONG ; Jongil KANG ; Seungjoon KIM ; Jin-Young CHUNG ; Sang-Soep NAHM ; Pan Dong RYU
Journal of Veterinary Science 2024;25(5):e71-
Objective:
This study aimed to establish the basic veterinary clinical skills required to ensure graduates of Korean veterinary universities have the day-one competency to independently perform their professional duties.
Methods:
The Education Committee of the Korean Association of Veterinary Medical Colleges, composed of veterinary school professors and an experienced veterinarian in the clinic, reviewed domestic and international veterinary education-related materials to define basic clinical skills.
Results:
The Korean Veterinarian Entrustable Professional Activities (KVEPA) was introduced, followed by the subsequent development of 54 essential clinical skills based on the KVEPA.
Conclusions
and Relevance: The veterinary basic clinical skills established through this study can be used as a specific guide for clinical education in Korean veterinary school, and is expected to play an important role in meeting the needs of the educational sector of the veterinary education accreditation standards.
10.Developing veterinary basic clinical skill items based on Korean Veterinary Entrustable Professional Activity
Kichang LEE ; Heungshik S. LEE ; Seong Mok JEONG ; Jongil KANG ; Seungjoon KIM ; Jin-Young CHUNG ; Sang-Soep NAHM ; Pan Dong RYU
Journal of Veterinary Science 2024;25(5):e71-
Objective:
This study aimed to establish the basic veterinary clinical skills required to ensure graduates of Korean veterinary universities have the day-one competency to independently perform their professional duties.
Methods:
The Education Committee of the Korean Association of Veterinary Medical Colleges, composed of veterinary school professors and an experienced veterinarian in the clinic, reviewed domestic and international veterinary education-related materials to define basic clinical skills.
Results:
The Korean Veterinarian Entrustable Professional Activities (KVEPA) was introduced, followed by the subsequent development of 54 essential clinical skills based on the KVEPA.
Conclusions
and Relevance: The veterinary basic clinical skills established through this study can be used as a specific guide for clinical education in Korean veterinary school, and is expected to play an important role in meeting the needs of the educational sector of the veterinary education accreditation standards.