复合酶法水解猪血生产血肽素

目前，水解各种蛋白大都采用强酸强碱，水解时间长，部分氨基酸被破坏，中和后产生大量的NaCl很难完全去除。采用复合酶法协同水解，解决了单酶水解成度低、强酸强碱水解破坏氨基酸的难题。

动物血液的开发研究

阐述了以动物血液为原料,利用现代生物技术开发生产保健食品血肽素,饲料添加剂血浆蛋白粉,发酵血粉,化妆品超氧化物歧化酶(SOD)的方法。

Investigation of Calcitonin and Calcitonin Gene-related Peptide in 88 Cases of Medullary Thyroid Carcinoma

Objective： To investigate the changes of calcitonin （CT） and calcitonin gene-related peptide （CGRP） in patients with medullary thyroid carcinoma （MTC）. Methods： Fifty-eight cases of MTC were selected and the relationship between the CT levels and metastasis was investigated. The immunohistochemical method was used to detect the expression of CT and CGRP in the 58 samples of MTC tissues. The CT and CGRP in 30 newly diagnosed MTC inpatients were measured before operation and in the first few days after operation using a radioimmunoassy. Results： （1） The rate of residual tumor had a significant difference between the normal serum CT group one month after operation and the elevated group at the same period （P〈0.01）. （2） Immunohistochemical study revealed the positive rate of CT was about 98%, and that of the CGRP was 87.8%. （3） Part of the patients had an elevated CGRP levels while CT levels was normal. （4） The serum CT levels were decreased to a stable range one week after operation. Conclusion： CT is a useful index to evaluate the efficacy of surgical treatment. The measurement of serum CGRP is helpful in the diagnosis of MTC, especially for those whose preoperative CT levels are normal.

Is Glucagon-like peptide-1, an agent treating diabetes, a new hope for Alzheimer's disease?

Glucagon-like peptide- 1 （GLP- 1） has been endorsed as a promising and attractive agent in the treatment of type 2 diabetes mellitus （T2DM）. Both Alzheimer＇s disease （AD） and T2DM share some common pathophysiologic hallmarks, such as amyloid β （Aβ）, phosphoralation of tau protein, and glycogen synthase kinase-3. GLP-1 possesses neurotropic properties and can reduce amyloid protein levels in the brain. Based on extensive studies during the past decades, the understanding on AD leads us to believe that the primary targets in AD are the Aβ and tau protein. Combine these findings, GLP- 1 is probably a promising agent in the therapy of AD. This review was focused on the biochemistry and physiology of GLP- 1, communities between T2DM and AD, new progresses of GLP - 1 in treating T2MD and improving some pathologic hanmarks of AD.

技术财源

1 需求项目名称:空气净化装置 所需项目主要内容:贯流风机的国产化 需求单位:杭州三以实业有限公司 电话:0571—88986288 邮政编码:310013 详细地址:杭州文苑路11号沁雅花园26幢 联系人:郑斌 Emau:Zb@sina.

EFFECTS OF CERTAIN VASOACTIVE PEPTIDES ON PATHOGENESIS OF VASCULAR RESTENOSIS

Objective.To investigate the effects of several vasoactive peptides on the development of arterial restenosis after balloon angioplasty. Methods. In rat aortic artery restenosis model produced by denudation of aortic endothelia,we observed changes of endothelin(ET),angiotensin II(AII),calcitonin gene-related peptide(CGRP)and adrenomedullin(Adm)in plasma and aorta with radioimmunoassay and expression of hypertension-related gene(HRG-1)with semi-quantitative RT-PCR,and studied the effects of these peptides on intimal hyperplasia,intima/media ratio and MAPK activities of aortic artery after angioplasty respectively. Furthermore,in cultured cells,we studied the effects of these peptides on vascular smooth muscle cell(VSMC) proliferation and expression of HRG-1 of VSMC from spontaneously hypertensive rats(SHR)and Wistar-Kyoto(WKY)rats with 3H-TdR incorporation and RT-PCR respectively. Results. After angioplasty,the levels of ET and AII in plasma and aorta significantly increased,accompanied with VSMC proliferation and neointima hyperplasia. On day 10 after angioplasty,the levels of ET in plasma and aorta increased by 69% and 124% respectively,compared with sham group(P<0.01);and the level of aortic AII increased by 80%(P< 0.01). Antiserum against ET or inhibitors of angiotensin converting enzyme(ACE)could significantly inhibit the proliferation of VSMC and neointima formation. Compared with the sham group,on day 3 after angioplasty,the CGRP levels in plasma and aorta increased by 64% and 89% respectively(P< 0.01)and the Adm levels in plasma and tissue increased by 129% and 102% respectively(P< 0.01). On day 10,intravenous administration of CGRP significantly inhibited the proliferation of VSMC and neointima forma-tion induced by balloon aortic injury(by 66% and 79% respectively,P< 0.01). In addition,ET and AII attenuated the expression of HRG-1 in aorta and stimulated mitogen-activated protein kinase(MAPK)activity,while CGRP and Adm potentiated the expression of HRG-1 and inhibited MAPK.Conclusions. ET and AII can stimulate the proliferation of injured intima while CGRP and Adm have an anti-hyperplasia effect after angioplasty. These 4 peptides are involved in the regulation of VSMC proliferation and affect the development of vascular restenosis by regulating the expression of HRG-1 and MAPK activity.

Levels of vasoactive intestinal peptide,cholecystokinin and calcitonin gene-related peptide in plasma and jejunum of rats following traumatic brain injury and underlying significance in gastrointestinal dysfunction

AIM:To study the alterations of brain-gut peptides following traumatic brain injury (TBI) and to explore the underlying significance of these peptides in the complicated gastrointestinal dysfunction.METHODS:Rat models of focal traumatic brain injury were established by impact insult method,and divided into 6 groups (6 rats each group) including control group with sham operation and TBI groups at postinjury 3,12,24,72h,and d 7.Blood and proximal jejunum samples were taken at time point of each group and gross observations of gastrointestinal pathology were recorded simultaneously.The levels of vasoactive intestinal peptide (VIP) in plasma,calcitonin gene-related peptide (CGRP) and cholecystokinin (CCK) in both plasma and jejunum were measured by enzyme immunoassay (EIA). Radioimmunoassay (RIA) was used to determine the levels of VIP in jejunum.RESULTS:Gastric distension,delayed gastric emptying and intestinal dilatation with a large amount of yellowish effusion and thin edematous wall were found in TBI rats through 12h and 72h, which peaked at postinjury 72h. As compared with that of control group (247.8±29.5ng/L), plasma VIP levels were significantly decreased at postinjury 3,12 and 24h (106.7±34.1ng/L, 148.7±22.8ng/L,132.8±21.6ng/L,respectively),but significantly increased at 72h (405.0±29.8ng/L) and markedly declined on d 7 (130.7±19.3ng/L).However,Plasma levels CCK and CGRP were significantly increased through 3h and 7d following TBI (126-691% increases),with the peak at 72 h.Compared with control (VIP, 13.6±1.4ng/g;CGRP,70.6±17.7ng/g);VIP and CGRP levels in jejunum were significantly increased at 3h after TBI (VIP,35.4±5.0ng/g;CGRP,103.8±22.1ng/g),and declined gradually at 12 h and 2d h (VIP,16.5±1.8ng/g,5.5±1.4ng/g;CGRP,34.9±9.7ng/g, 18.5±7.7ng/g),but were significantly increased again at 72 h (VIP, 48.7±9.5ng/g; CGRP,142.1±24.3ng/g),then declined in various degrees on d 7 (VIP, 3.8±1.1ng/g; CGRP, 102.5±18.1ng/g).The CCK levels in jejunum were found to change in a similar trend as that in plasma with the concentrations of CCK significantly increased following TBI (99-517% increases) and peaked at 72h.CONCLUSION:Traumatic brain injury can lead to significant changes of brain-gut peptides in both plasma and small intestine, which may be involved in the pathogenesis of complicated gastrointestinal dysfunction.

Liraglutide reduces oxidized LDL-induced oxidative stress and fatty degen- eration in Raw 264.7 cells involving the AMPK/SREBP1 pathway

Baekgound Recent studies have suggested a potential role for liraglutide in the prevention and stabilization ofatherosclerotic vascular disease. However, the molecular mechanisms underlying the effect of liraglutide on atherosclerosis have not been well elucidated. The pur- pose of this study was to examine whether liraglutide protects against oxidative stress and fatty degeneration via modulation of AMP-activated protein kinase （AMPK）/sterol regulatory element binding transcription factor 1 （SREBP1） signaling pathway in foam ceils. Methods Mouse macrophages Raw264.7 cells were exposed to oxidized low density lipoprotein （oxLDL） to induce the formation of foam cells. The cells were incubated with oxLDL （50 μg/mL）, liraglutide （0.1, 0.5, 1 and 2 nmol/L） or exendin-3 （9-39） （1, 10 and 100 nmol/L） alone, or in combination. Oil Red O staining was used to detect intracellular lipid droplets. The levels of TG and cholesterol were measured using the commercial kits. Oxidative stress was determined by measuring intracellular reactive oxygen species （ROS）, malondialdehyde （MDA） and superoxide dismutase 1 （SOD）. Western blot analysis was used to examine the expression of AMPKal, SREBP1, phosphory- lated AMPKal, phosphorylated SREBP1, glucagon-like peptide-1 （GLP-1） and GLP-1 receptor （GLP-1R）. Results Oil Red O staining showed that the cytoplasmic lipid droplet accumulation was visibly decreased in foam cells by treatment with liraglutide. The TG and cholesterol content in the liraglutide-treated foam cells was significantly decreased. In addition, foam ceils manifested an impaired oxidative stress following liraglutide treatment, as evidenced by increased SOD, and decreased ROS and MDA. However, these effects of liraglutide on foam cells were attenuated by the use of GLP-IR antagonist exendin-3 （9-39）. Furthermore, we found that the expression level of AMPKa 1 and phosphorylated AMPKct 1 was significantly increased while the expression level of SREBP 1 and phosphorylated SREBP 1 was significantly decreased in foam cells following treatment with liraglutide. Conclusions This study for the first time demonstrated that the effect of liraglutide on reducing oxidative stress and fatty degeneration in oxLDL-induced Raw264.7 cells is accompanied by the alteration of AMPK/SREBP1 pathway. This study provided a potential molecular mechanism for the effect of liraglutide on reducing oxidative stress and fatty degeneration.

Uncoupling protein 2 regulates glucagon-like peptide-1 secretion in L-cells

AIM:To investigate whether uncoupling protein 2(UCP2) affects oleic acid-induced secretion of glucagonlike peptide-1(GLP-1) in L-cells.METHODS:mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells,which serve as a model for enteroendocrine L-cells,by quantitative reverse transcription-polymerase chain reaction and Western blotting before and after treatment with oleic acid.Localization of UCP2 and GLP-1 in NCI-H716 cells was assessed by immunofluorescence labeling.NCI-H716 cells were transiently transfected with a small interfering RNA(siRNA) that targets UCP2(siUCP2) or with a nonspecific siRNA using Lipofectamine 2000.The concentrations of bioactive GLP-1 in the medium were measured by enzyme linked immunosorbent assay.RESULTS:Both GLP-1 and UCP2 granules were expressed mainly in the cytoplasm of NCI-H716 cells.NCI-H716 cells that secreted GLP-1 also expressed UCP2.Time-course experiments revealed that release of GLP-1 from NCI-H716 cells into the medium reached a maximum at 120 min and remained stable until at least 180 min after treatment with oleic acid(the level of GLP-1 increased about 2.3-fold as compared with the level of GLP-1 in the control cells,P < 0.05).In an experiment to determine dose dependence,stimulation of NCI-H716 cells with ≤ 8 mmol oleic acid led to a concentration-dependent release of GLP-1 into the medium;10 mmol oleic acid diminished the release of GLP-1.Furthermore,GLP-1 secretion induced by oleic acid from NCI-H716 cells that were transfected with siUCP2 decreased to 41.8%,as compared with NCI-H716 cells that were transfected with a non-specific siRNA(P < 0.01).CONCLUSION:UCP2 affected GLP-1 secretion induced by oleic acid.UCP2 plays an important role in L-cell secretion that is induced by free fatty acids.

Olive oil consumption and non-alcoholic fatty liver disease

The clinical implications of non-alcoholic fatty liver diseases(NAFLD)derive from their potential to progress to fibrosis and cirrhosis.Inappropriate dietary fat intake,excessive intake of soft drinks,insulin resistance and increased oxidative stress results in increased free fatty acid delivery to the liver and increased hepatic triglyceride(TG)accumulation.An olive oil-rich diet decreases accumulation of TGs in the liver,improves postprandial TGs,glucose and glucagonlike peptide-1 responses in insulin-resistant subjects, and upregulates glucose transporter-2 expression in the liver.The principal mechanisms include:decreased nuclear factor-kappaB activation,decreased lowdensity lipoprotein oxidation,and improved insulin resistance by reduced production of inflammatory cytokines(tumor necrosis factor,interleukin-6)and improvement of jun N-terminal kinase-mediated phosphorylation of insulin receptor substrate-1.The beneficial effect of the Mediterranean diet is derived from monounsaturated fatty acids,mainly from olive oil.In this review,we describe the dietary sources of the monounsaturated fatty acids,the composition of olive oil,dietary fats and their relationship to insulin resistance and postprandial lipid and glucose responses in non-alcoholic steatohepatitis,clinical and experimental studies that assess the relationship between olive oil and NAFLD,and the mechanism by which olive oil ameliorates fatty liver,and we discuss future perspectives.

Octreotide reverses shock due to vasoactive intestinal peptide-secreting adrenal pheochromocytoma: A case report and review of literature

Vasoactive intestinal peptide-producing tumors （VIP-oma） usually originate in the pancreas and are chara-cterized by diarrhea, hypokalemia, and achlorhydria （WDHA syndrome）. In adults, nonpancreatic VIPoma is very rare. Herein, we report an unusual case of VIP-producing pheochromocytoma marked by persistent shock, fushing, and watery diarrhea and high sensitivity to octreotide. A 53-year-old woman was hospitalized for sudden-onset hypertension with convulsions, which then rapidly evolved to persistent shock, fushing, and watery diarrhea. Abdominal computed tomography indicated a left adrenal mass, accompanied by bleeding;and marked elevations of both plasma catecholamine and VIP concentrations were documented via laboratory testing. Surprisingly, all clinical symptoms responded swiftly to octreotide treatment. Once surgically treated, hormonal levels normalized in this patient, and the clinical symptoms dissipated. Postoperative pathological and immunohistopathological studies confrmed a VIP-secreting pheochromocytoma with strong, diffuse positivity for somatostatin receptor type 2. During a 6-mo follow-up period, she seemed in good health andwas symptom-free.

Ghrelin's second life:From appetite stimulator to glucose regulator

Ghrelin,a 28 amino acid peptide hormone produced by the stomach,was the first orexigenic hormone to be discovered from the periphery.The octanoyl modification at Ser3,mediated by ghrelin O-acyltransferase(GOAT),is essential for ghrelin's biological activity.Ghrelin stimulates food intake through binding to its receptor(GRLN-R) on neurons in the arcuate nucleus of the hypothalamus.Ghrelin is widely expressed throughout the body;accordingly,it is implicated in several other physiological functions,which include growth hormone release,gastric emptying,and body weight regulation.Ghrelin and GRLN-R expression are also found in the pancreas,suggesting a local physiological role.Accordingly,several recent studies now point towards an important role for ghrelin and its receptor in the regulation of blood glucose homeostasis,which is the main focus of this review.Several mechanisms of this regulation by ghrelin have been proposed,and one possibility is through the regulation of insulin secretion.Despite some controversy,most studies suggest that ghrelin exerts an inhibitory effect on insulin secretion,resulting in increased circulating glucose levels.Ghrelin may thus be a diabetogenic factor.Obesity-related type2 diabetes has become an increasingly important health problem,almost reaching epidemic proportions in the world;therefore,antagonists of the ghrelin-GOAT signaling pathway,which will tackle both energy-and glucose homeostasis,may be considered as promising new therapies for this disease.

Octreotide ameliorates gastric lesions in chronically mild stressed rats

AIM:To evaluate the effect of chronic mild stress(CMS) on the emergence of gastric ulcers and possible modulation by octreotide,a synthetic somatostatin analogue. METHODS:Adult male Wistar rats were subjected to nine different unpredictable random stress procedures for 21 d,a multifactorial interactional animal model for CMS.Octreotide was administered daily for 21 d at two dose levels(50 and 90μg/kg)before exposure to stress procedure.Macro-and microscopical assessments were made,in addition to quantification of plasma corticosterone and gastric mucosal inflammatory,oxidative stress, and apoptotic biomarkers. RESULTS:Exposure to CMS elevated plasma corticosterone(28.3±0.6μg/dL,P=0.002),an event that was accompanied by gastric lesions(6.4±0.16 mm,P=0.01) and confirmed histopathologically.Moreover,the insult elevated gastric mucosal lipid peroxides(13±0.5 nmol/g tissue,P=0.001),tumor necrosis factor-α(3008.6±78.18 pg/g tissue,P<0.001),prostaglandin E2(117.1 ±4.31 pg/g tissue,P=0.002),and caspase-3 activity (2.4±0.14 OD/mg protein,P=0.002).Conversely,CMS mitigated interleukin-10(627.9±12.82 pg/g tissue,P= 0.001).Furthermore,in animals exposed to CMS,octreotide restored plasma corticosterone(61%and 71%from CMS,P=0.002)at both dose levels.These beneficial effects were associated with a remarkable suppression of gastric lesions(38%and 9%from CMS,P=0.01)and reversal of derangements in gastric mucosa. CONCLUSION:The current investigation provides evidence that exposure to CMS induces gastric ulceration, which was alleviated by administration of octreotide possibly possessing antioxidant,anti-inflammatory,and anti-apoptotic actions.

Effects of psychological stress on small intestinal motility and expression of cholecystokinin and vasoactive intestinal polypeptide in plasma and small intestine in mice

AIM: To investigate the effects of psychological stress on small intestinal motility and expression of cholecystokinin (CCK) and vasoactive intestinal polypeptide (VIP) in plasma and small intestine, and to explore the relationship between small intestinal motor disorders and gastrointestinal hormones under psychological stress. METHODS: Thirty-six mice were randomly divided into psychological stress group and control group. A mouse model with psychological stress was established by housing the mice with a hungry cat in separate layers of a two-layer cage. A semi-solid colored marker (carbon-ink) was used for monitoring small intestinal transit. CCK and VIP levels in plasma and small intestine in mice were measured by radioimmunoassay (RIA). RESULTS: Small intestinal transit was inhibited (52.18±19.15% vs70.19±17.79%, P<0.01) in mice after psychological stress, compared to the controls. Small intestinal CCK levels in psychological stress mice were significantly lower than those in the control group (0.75±0.53 μg/g vs1.98±1.17 μg/g, P<0.01), whereas plasma CCK concentrations were not different between the groups. VIP levels in small intestine were significantly higher in psychological stress mice than those in the control group (8.45±1.09 μg/g vs7.03±2.36 μg/g, P<0.01), while there was no significant difference in plasma VIP levels between the two groups. CONCLUSION: Psychological stress inhibits the small intestinal transit, probably by down-regulating CCK and up-regulating VIP expression in small intestine.

Pernicious anemia: What are the actual diagnosis criteria?

A gastric intrinsic factor output under 200 U/h after pentagastrin stimulation (N > 2000 U/h) is specific for pernicious anemia. The other findings are either variable or non specific. Serum intrinsic factor antibodies, considered as specific in general practice, are present only in half of the patients with pernicious anemia. In their absence, since the disappearance of the Schilling tests, the gastric tubage currently used for the study of gastric acid secretion, is obligatory for the simultaneous study of intrinsic factor output. This study is important to eliminate another disease much more frequent than pernicious anemia, the protein bound to cobalamin malabsorption was observed in achlorhydric simple atrophic gastritis in the presence of intrinsic factor secretion.

Changing the treatment of heart failure with reduced ejection fraction： clinical use of sacubitril-valsartan combination

Despite significant therapeutic advances, patients with chronic heart failure （HF） remain at high risk of morbidity and mortality. Sacubitill valsartan （previously known as LCZ696） is a new oral agent approved for the treatment of symptomatic chronic heart failure in adults with reduced ejection fraction. It is described as the fast in class angiotensin receptor neprilysin inhibitor （ARNI） since it incorporates the neprilysin inhibitor, sacubitril and the angiotensin Ⅱ receptor antagonist, valsartan. Neprilysin is an endopeptidase that breaks down several vasoactive peptides including natriuretic peptides （NPs）, bradykinin, endothelin and angiotensin II （Ang-II）. Therefore, a natural consequence of its inhibition is an increase of plasmatic levels of both, NPs and Ang-Ⅱ （with opposite biological actions）. So, a combined inhibition of these both systems （Sacubitril / valsartan） may enhance the benefits of NPs effects in HF （natriuresis, diuresis, etc） while Ang-Ⅱ receptor is inhibited （reducing vasoconstriction and aldosterone release）. In a large clinical trial （PARADIGM-HF with 8442 patients）, this new agent was found to significantly reduce cardiovascular and all cause mortality as well as hospitalizations due to HF （compared to enalapril）. This manuscript reviews clinical evidence for sacubitril valsartan, dosing and cautions, future directions and its considered place in the therapy of HF with reduced ejection fraction.

The cardiovascular action of hexarelin

Hexarelin, a synthetic growth hormone-releasing peptide, can bind to and activate the growth hormone secretagogue receptor （GHSR） in the brain similar to its natural analog ghrelin. However, the peripheral distribution of GHSR in the heart and blood vessels suggests that hexarelin might have direct cardiovascular actions beyond growth hormone release and neuroendocrine effects. Furthermore, the non-GHSR CD36 had been demonstrated to be a specific cardiac receptor for hexarelin and to mediate its cardioprotective effects. When compared with ghrelin, hexarelin is chemically more stable and functionally more potent. Therefore, it may be a promising therapeutic agent for some car-diovascular conditions. In this concise review, we discuss the current evidence for the cardiovascular action of hexarelin.

Purification and Characterization of Angiotensin I Converting Enzyme Inhibition Peptides from Sandworm Sipunculus nudus

Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chromatography and reverse-phase high performance liquid chromatography(RP-HPLC), were used to isolate the ACE inhibition peptides. The amino acid sequences of the peptides were identified as Ile-Asn-Asp, Val-Glu-Pro-Gly and Leu-Ala-Asp-Glu-Phe. The IC_(50) values of the purified peptides for ACE inhibition activity were 34.72 μmol L^(-1), 20.55 μmol L^(-1) and 22.77 μmol L^(-1), respectively. These results suggested that S. nudus proteins contain specific peptides that can be released by enzymatic hydrolysis. This study may provide an experimental basis for further systematic research, rational development and clinical utilization of sandworm resources.

Advancements in glucagon-like peptide-1 receptor agonist therapy for type 2 diabetes

Glucagon-like peptide-1 receptor agonists(GLP-1RAs)are novel hypoglycemic agents that have garnered widespread acceptance in the treatment of type 2 diabetes,largely attributed to their safety profile,potent hypoglycemic effects,and metabolic advantages.Their primary mechanisms of action encompass promoting insulin release,inhibiting glucagon secretion,bolstering pancreatic islet cell function,curbing appetite,and slowing gastric emptying.This article delves into the clinical evidence underscoring the efficacy of various GLP-1RAs.Notably,these agents have demonstrated marked improvements in glycemic control,significant weight reduction,and substantial cardiovascular and renal protection.Nonetheless,certain adverse effects of GLP-1RAs,such as pancreatitis and intestinal obstruction,have been reported,warranting vigilant monitoring by healthcare professionals.In sum,GLP-1RAs hold significant promise in the management of type 2 diabetes,offering notable cardiovascular and renal advantages.