• Journal of Life Science
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• v.21 no.4
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• pp.494-501
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• 2011

To understand the relationship between coat color inheritance patterns and genotypes of Extension (E) and Agouti (A) loci in cattle, the genotypes for melanocortin-1 receptor (MC1R) and agouti signaling protein (ASIP) were analyzed in Hanwoo, Jeju black cattle (JBC), and their crossbred progeny. Three MC1R alleles ($E^D$, $E^+$, and e) were found in the black-colored JBC population. JBC had no recessive homozygotes (e/e), but this genotype was predominant in the Hanwoo breed. However, MC1R $E^+$/e Hanwoo did not produce a black coat color as they appeared either as brown or solid red. For ASIP, three genotypes (A/A, A/$A^{Br}$, and $A^{Br}/A^{Br}$) were determined by insertion/deletion of an L1-BT element in Hanwoo. The ASIP $A^{Br}$ allele was rarely observed, and no ASIP $A^{Br}/A^{Br}$ homozygotes were detected in the JBC population. Cattle carrying ASIP $A^{Br}$ did not show any agouti-like brindle pigmentation patterns in either breed or their progeny. The coat colors of the crossbred progeny were discriminated by two colors, yellowish-brown versus dark-brown or black, and their coat colors were directly related to the genotypes of the Extension locus, yellowish-brown (e/e) and dark-brown or black ($E^+$/e), but not to the Agouti locus. ASIP genotypes probably did not affect coat color development in the Hanwoo or crossbred progeny. Our results suggest that the ASIP genotypes do not play key roles in coat color variation, but the MC1R genotypes do direct the phenotypes of Hanwoo, JBC, and their progeny.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.5
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• pp.273-282
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• 2006

The aim of the present study was to investigate the effects of R-(-)-2,10,11-trihydroxy-N-propylnoraporphine [R-(-)-TNPA], a selective agonist of dopaminergic $D_2$ receptor and S(-)-raclopride, a selective antagonist of dopaminergic $D_2$ receptor, on the secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane-depolarization in the isolated perfused model of the rat adrenal gland, and also to establish its mechanism of action. R-(-)-TNPA $(10{\sim}100\;{\mu}M)$ perfused into an adrenal vein for 60 min produced dose- and time-dependent inhibition in CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM), DMPP $(100\;{\mu}M)$ and McN-A-343 $(100\;{\mu}M)$. R-(-)-TNPA itself did also fail to affect basal CA output. Also, in adrenal glands loaded with R-(-)-TNPA $(30\;{\mu}M)$, the CA secretory responses evoked by Bay-K-8644 $(10\;{\mu}M)$, an activator of L-type $Ca^2+$ channels and cyclopiazonic acid $(10\;{\mu}M)$, an inhibitor of cytoplasmic $Ca^{2+}-ATPase$ were also inhibited. However, S(-)-raclopride $(1{\sim}10\;{\mu}M)$, given into an adrenal vein for 60 min, enhanced the CA secretory responses evoked by ACh, high $K^+$, DMPP and McN-A-343 only for the first period (4 min), although it alone has weak effect on CA secretion. Moreover, S(-)-raclopride $(3.0\;{\mu}M)$ in to an adrenal vein for 60 min also augmented the CA release evoked by BAY-K-8644 and cyclopiazonic acid only for the first period (4 min). However, after simultaneous perfusion of R-(-)-TNP A $(30\;{\mu}M)$ and S(-)-raclopride $(3.0\;{\mu}M)$, the inhibitory responses of R(-)-TNPA $(30\;{\mu}M)$ on the CA secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644, and cyclopiazonic acid were significantly reduced. Taken together, these experimental results suggest that R-(-)-TNPA greatly inhibits the CA secretion from the perfused rat adrenal medulla evoked by cholinergic stimulation (both nicotininc and muscarinic receptors) and membrane depolarization, but S(-)-raclopride rather enhances the CA release by them. It seems that this inhibitory of R-(-)-TNPA may be mediated by stimulation of inhibitory dopaminergic $D_2$ receptors located on the rat adrenomedullary chromaffin cells, while the facilitatory effect of S(-)-raclopride is due to the blockade of dopaminergic $D_2$ receptors, which are relevant to extra- and intracellular calcium mobilization. Therefore, it is thought that dopaminergic $D_2$ receptors may be involved in regulation of CA release in the rat adrenal medulla.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.223-230
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• 2005

The purpose of the present study was to examine the effect of naltrexone, an opioid antagonist, on secretion of catecholamines (CA) evoked by cholinergic nicotinic stimulation and membrane-depolarization from the isolated perfused rat adrenal gland and to establish the mechanism of its action. Naltrexone $(3{\times}10^{-6}M)$ perfused into an adrenal vein for 60 min produced time-dependent inhibition in CA secretory responses evoked by ACh $(5.32{\times}10^{-3}M)$ , high $K^+$ $(5.6{\times}10^{-2}M)$ , DMPP ($10^{-4}$ M) and McN-A-343 $(10^{-4}M)$ . Naltrexone itself did also fail to affect basal CA output. In adrenal glands loaded with naltrexone $(3{\times}10^{-6}M)$ , the CA secretory responses evoked by Bay-K-8644, an activator of L-type $Ca^{2+}$ channels and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}-ATPase$, were also inhibited. However, in the presence of met-enkephalin $(5{\times}10^{-6}M)$ , a well-known opioid agonist, the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly inhibited. Collectively, these experimental results demonstrate that naltrexone inhibits greatly CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as that by membrane depolarization. It seems that this inhibitory effect of naltrexone does not involve opioid receptors, but might be mediated by blocking both the calcium influx into the rat adrenal medullary chromaffin cells and the uptake of $Ca^{2+}$ into the cytoplasmic calcium store, which are at least partly relevant to the direct interaction with the nicotinic receptor itself.

• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.1-8
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• 2012

This study aimed to investigate the single nucleotide polymorphisms (SNPs) of the porcine MC4R gene and validate the effect of the MC4R genotype for marker assisted selection (MAS). Six amplicons were produced to analyze the entire base sequences of the porcine MC4R gene and six SNPs were detected (c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, c.892A>G-Asp298Asn, and c.*430A>T). Linkage disequilibrium (LD) of the six SNPs was analyzed by performing haploid analysis. There was a perfect linkage disequilibrium in c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, and c.*430A>T. Only the c.892A>G (Asp298Asn) SNP showed a very low LD with an $r^2$ value of 0.028 and the D' value of 0.348. As a result, the two SNPs-c.707A>G (Arg236His) and c.892A>G (Asp298Asn)-were selected to extract the genotype frequencies from the 5 pig breeds by using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotype analysis method. The SNP frequency of c.707A>G (Arg236His) indicated the presence of the A (His) allele only in Yorkshire, while the G allele was fixed in the KNP, Landrace, Berkshire, and Duroc. Association analysis was carried out in 484 pigs with the c.707A>G (Arg236His) SNP and the meat quality traits of four different pig cross populations: a significant association was noted in crude fat, sirloin moisture, meat color, and the degree of red and yellow coloration. The frequency of the c.892A>G(Asp298Asn) SNP genotype varied among the breeds; while Duroc showed the highest frequency of the A (Asn) allele, KNP showed the highest frequency of the G (Asp) allele. Association analysis was carried out in 1126 pigs with the c.892A>G (Asp298Asn) SNP and the meat quality traits of four pig populations: a highly significant linkage was noted in the back-fat thickness (P<0.002). It was found that the back-fat thickness was higher in individuals with the AA genotype than in those with the AG or GG genotype. Thus, in this study, we verified that the c.892A>G (Asp298Asn) SNP in the pig MC4R gene has a sufficient effect as a gene marker for MAS in Korean pork industry.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.3
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• pp.236-246
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• 2024

Objective: Nicotinamide mononucleotide (NMN) is extensively utilized as an anti-aging agent and possesses anti-inflammatory properties. Lipopolysaccharide (LPS) activates Toll-like receptor 4, a process modulated by intracellular signaling pathways such as the Wnt/β-catenin pathway. This study investigated the impact of NMN on osteogenesis in the presence of LPS. Methods: To elucidate the role of NMN in osteogenesis in the context of Gram-negative bacterial infection after LPS treatment, we cultured a mouse pre-osteoblast cell line (MC3T3-E1) and subsequently incubated it with NMN and/or LPS. We then evaluated osteogenic activity by measuring alkaline phosphatase activity, assessing gene expression and protein levels, and performing Alizarin Red S staining and immunocytochemistry. Results: MC3T3-E1 cells underwent successful differentiation into osteoblasts following treatment with osteogenic induction medium. LPS diminished features related to osteogenic differentiation, which were subsequently partially reversed by treatment with NMN. The restorative effects of NMN on LPS-exposed MC3T3-E1 cells were further substantiated by elucidating the role of Wnt/β-catenin signaling, as confirmed through immunocytochemistry. Conclusion: This study showed that infection with Gram-negative bacteria disrupted the osteogenic differentiation of MC3T3-E1 cells. This adverse effect was partially reversed by administering a high-dose of NMN. Drawing on these results, we propose that NMN could serve as a viable therapeutic strategy to preserve bone homeostasis in elderly and immunocompromised patients.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.668-672
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• 2009

This paper describes the differentiation between native Korean cattle (Hanwoo) and Holsteins or imported cattle using the real-time polymerase chain reaction (PCR) by targeting the sequence of the melanocortin 1 receptor (MC1R) gene. A rapid and accurate method was developed to identify Hanwoo by genotyping the DNA extracted from 295 commercial beef samples (obtained from 5 provinces in South Korea) labeled as Hanwoo beef. The results of real-time PCR assays for the proportions of Hanwoo were 84, 85.7, 95, 91.4, and 90% in the areas of Seoul, Joongbu, Youngnam, Honam, and Chungcheong, respectively. Thus, the beef samples from 295 butcher shops, which asserted to only sell Hanwoo, showed that 259 of 295 samples were of the Hanwoo beef gene type (T-type) and 36 of 295 samples were Holsteins of imported dairy cattle gene types (C-type or C/T type). In conclusion, the proportion of Hanwoo beef was 87.8% and the proportion of Holstein or imported dairy cattle meat was 12.2% (C-type: 9.8%, C/T-type: 2.4%). Generally, most consumers can not differentiate imported meat from Hanwoo beef. Therefore, Hanwoo beef and imported dairy cattle meat that is sold in butcher shops should have mandatory identification by using MC1R genotyping based on real-time PCR.

• Biomolecules & Therapeutics
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• v.15 no.2
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• pp.108-117
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• 2007

The aim of the present study was to investigate the effect of glibenclamide, a hypoglycemic sulfonylurea, which selectively blocks ATP-sensitive K$^+$ channels, on secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane depolarization from the isolated perfused rat adrenal glands. The perfusion of glibenclamide (1.0 mM) into an adrenal vein for 90 min produced time-dependently enhanced the CA secretory responses evoked by ACh (5.32 mM), high K$^+$ (a direct membrane depolarizer, 56 mM), DMPP (a selective neuronal nicotinic receptor agonist, 100 ${\mu}$M for 2 min), McN-A-343 (a selective muscarinic M1 receptor agonist, 100 ${\mu}$M for 2 min), Bay-K-8644 (an activator of L-type dihydropyridine Ca$^{2+}$ channels, 10 ${\mu}$M for 4 min) and cyclopiazonic acid (an activator of cytoplasmic Ca$^{2+}$-ATPase, 10 ${\mu}$M for 4 min). In adrenal glands simultaneously preloaded with glibenclamide (1.0 mM) and nicorandil (a selective opener of ATP-sensitive K$^+$ channels, 1.0 mM), the CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were recovered to the considerable extent of the control release in comparison with that of glibenclamide-treatment only. Taken together, the present study demonstrates that glibenclamide enhances the adrenal CA secretion in response to stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization from the isolated perfused rat adrenal glands. It seems that this facilitatory effect of glibenclamide may be mediated by enhancement of both Ca$^{2+}$ influx and the Ca$^{2+}$ release from intracellular store through the blockade of K$_{ATP}$ channels in the rat adrenomedullary chromaffin cells. These results suggest that glibenclamide-sensitive K$_{ATP}$ channels may play a regulatory role in the rat adrenomedullary CA secretion.

• Archives of Pharmacal Research
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• v.28 no.6
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• pp.699-708
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• 2005

The present study was designed to investigate the effect of naloxone, a well known opioid antagonist, on the secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane-depolarization in the isolated perfused rat adrenal glands, and to establish its mechanism of action. Naloxone ($10^{-6}\~10^{-5}$ M), perfused into an adrenal vein for 60 min, produced dose- and time-dependent inhibition of CA secretory responses evoked by ACh ($5.32\times10^{-3}$ M), high K+ ($5.6\times10^{-2}$ M), DMPP ($10^{-4}$ M) and McN-A-343 ($10^{-4}$ M). Naloxone itself also failed to affect the basal CA output. In adrenal glands loaded with naloxone ($3\times10^{-6}$ M), the CA secretory responses evoked by Bay-K-8644, an activator of L-type $Ca^{2+}$ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}$-ATPase, were also inhibited. In the presence of met-enkephalin ($5\times10^{-6}$ M), a well known opioid agonist, the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly inhibited. Taken together, these results suggest that naloxone greatly inhibits the CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as that by membrane depolarization. It seems that these inhibitory effects of naloxone does not involve opioid receptors, but might be mediated by blocking both the calcium influx into the rat adrenal medullary chromaffin cells and the uptake of $Ca^{2+}$ into the cytoplasmic calcium store, which are at least partly relevant to the direct interaction with the nicotinic receptor itself.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1229-1238
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• 2016

This study was conducted to determine the relationships of five intragenic single nucleotide polymorphism (SNP) markers (protein kinase adenosine monophosphate-activated ${\gamma}3$ subunit [PRKAG3], fatty acid synthase [FASN], calpastatin [CAST], high mobility group AT-hook 1 [HMGA1], and melanocortin-4 receptor [MC4R]) and meat quality traits of Duroc breeding stocks in Korea. A total of 200 purebred Duroc gilts from 8 sires and 40 dams at 4 pig breeding farms from 2010 to 2011 reaching market weight (110 kg) were slaughtered and their carcasses were chilled overnight. Longissimus dorsi muscles were removed from the carcass after 24 h of slaughter and used to determine pork properties including carcass weight, backfat thickness, moisture, intramuscular fat, $pH_{24h}$, shear force, redness, texture, and fatty acid composition. The PRKAG3, FASN, CAST, and MC4R gene SNPs were significantly associated with the meat quality traits (p<0.003). The meats of PRKAG3 (A 0.024/G 0.976) AA genotype had higher pH, redness and texture than those from PRKAG3 GG genotype. Meats of FASN (C 0.301/A 0.699) AA genotype had higher backfat thickness, texture, stearic acid, oleic acid and polyunsaturated fatty acid than FASN CC genotype. While the carcasses of CAST (A 0.373/G 0.627) AA genotype had thicker backfat, and lower shear force, palmitoleic acid and oleic acid content, they had higher stearic acid content than those from the CAST GG genotype. The MC4R (G 0.208/A 0.792) AA genotype were involved in increasing backfat thickness, carcass weight, moisture and saturated fatty acid content, and decreasing unsaturated fatty acid content in Duroc meat. These results indicated that the five SNP markers tested can be a help to select Duroc breed to improve carcass and meat quality properties in crossbred pigs.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.3
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• pp.243-251
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• 2001

The present study was attempted to investigate the effect of strychnine on catecholamine (CA) secretion evoked by ACh, high $K^+,$ DMPP and McN-A-343 from the isolated perfused rat adrenal gland. The perfusion of strychnine $(10^{-4}\;M)$ into an adrenal vein for 20 min produced great inhibition in CA secretory responses evoked by ACh $(5.32{\times}10^{-3}\;M),$ DMPP $(10^{-4}\;M\;for\;2\;min)$ and McN-A-343 $(10^{-4}\;M\;for\;2\;min),$ but did not alter CA secretion by high $K^+\;(5.6{\times}10^{-2}\;M).$ Strychnine itself did also fail to affect basal catecholamine output. Furthermore, in adrenal glands preloaded simultaneously with strychnine $(10^{-4}\;M)$ and glycine (an agonist of glycinergic receptor, $10^{-4}\;M),$ CA secretory responses evoked by ACh, DMPP and McN-A-343 were considerably recovered to some extent when compared with those evoked by treatment with strychnine only. However, CA secretion by high $K^+\;(5.6{\times}10^{-2}\;M)$ was not affected. Taken together, these results demonstrate that strychnine inhibits greatly the CA secretory responses evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors, but does not affect that by membrane depolarization. It is suggested that strychnine-sensitive glycinergic receptors are localized in rat adrenal medullary chromaffin cells.