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1.
RSC Adv ; 8(46): 26335-26340, 2018 Jul 19.
Article in English | MEDLINE | ID: mdl-35541947

ABSTRACT

The relationship between the charge-discharge properties and crystal structure of Na x Li0.67+y Ni0.33Mn0.67O2 (0.010 ≤ x ≤ 0.013, 0.16 ≤ y ≤ 0.20) has been investigated. Li/Na x Li0.67+y Ni0.33Mn0.67O2 cells exhibit gradually sloping initial charge and discharge voltage-capacity curves. The initial charge capacity increased from 171 mA h g-1 for thermally-treated Na0.15Li0.51Ni0.33Mn0.67O2 to 226 mA h g-1 for Na0.010Li0.83Ni0.33Mn0.67O2 with an increase in the Li content. The initial maximum discharge capacity was 252 mA h g-1 in the case of Na0.010Li0.83Ni0.33Mn0.67O2 between 4.8 and 2.0 V at a fixed current density of 15 mA g-1 (0.06C) at 25 °C. The predominance of the spinel phase leads to the high initial discharge capacity of Na0.010Li0.83Ni0.33Mn0.67O2. This study shows that chemical lithiation using LiI is effective to improve the electrochemical properties.

2.
CPT Pharmacometrics Syst Pharmacol ; 6(7): 413-415, 2017 07.
Article in English | MEDLINE | ID: mdl-28568566

ABSTRACT

In Japan in October 2016, the Pharmaceuticals and Medical Devices Agency (PMDA) began to receive electronic data in new drug applications (NDAs). These electronic data are useful to conduct regulatory assessment of sponsors' submissions and contribute to the PMDA's research. In this article, we summarize the number of submissions of quantitative modeling and simulation (M&S) documents in NDAs in Japan, and we describe our current thinking and activities about quantitative M&S in PMDA.


Subject(s)
Drug Approval , Models, Theoretical , Computer Simulation , Government Agencies , Humans , Japan
3.
Neurogastroenterol Motil ; 23(11): 1020-8, e497, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21883699

ABSTRACT

BACKGROUND: The transient receptor potential vanilloid 4 (TRPV4), a thermo-sensitive stretch-activated cation channel, is expressed in the skin stratified squamous epithelium, contributing to the acquisition of barrier function. Similarly, functional TRPV4 may be located in the stratified squamous epithelial lining of the esophagus, being involved in the pathogenesis of gastroesophageal reflux disease (GERD). Here we investigated the expression of TRPV4 in the mouse esophageal epithelium. METHODS: TRPV4 expression at the mRNA and protein levels was examined by reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry. A calcium imaging technique and ATP assay were used to evaluate the functionality of TRPV4 in freshly isolated esophageal epithelial cells. KEY RESULTS: Transcripts and proteins encoding TRPV4 were colocalized in the basal and intermediate layers of the esophageal epithelium. Both 4α-phorbol 12,13- didecanoate (4α-PDD), a selective agonist for TRPV4, and hypo-osmolar solution (160 mOsm) elevated the intracellular calcium concentration ([Ca(2+) ](i) ) in a subset of the isolated cells (70%). These [Ca(2+) ](i) increases were potently inhibited by ruthenium red (RuR), a TRPV4 channel antagonist, and were suppressed by extracellular protons (pH 5.0). Finally, application of 4α-PDD evoked ATP release in primary esophageal epithelial cells. CONCLUSIONS & INFERENCES: Acid-sensitive TRPV4 channels were mainly expressed in the esophageal epithelial cells of the basal and intermediate layers. Direct exposure of TRPV4-expressing cells to gastric acid, as would occur in cases of GERD, could influence their cellular functions, possibly aggravating the disease state.


Subject(s)
Acids/metabolism , Calcium/metabolism , Epithelial Cells/physiology , Esophagus/cytology , TRPV Cation Channels/metabolism , Animals , Epithelial Cells/cytology , HEK293 Cells , Humans , Male , Mice , Mice, Inbred C57BL , TRPV Cation Channels/genetics
4.
Am J Nephrol ; 20(4): 263-7, 2000.
Article in English | MEDLINE | ID: mdl-10970977

ABSTRACT

In this report, we describe 5 patients with cholesterol atheroembolic renal failure. In 3 of the 5 patients, combined therapy with corticosteroids and plasma exchange was performed. These 3 patients survived, with 2 showing an improvement in renal function. The 2 remaining patients died of multifactorial causes. The literature on therapy for cholesterol atheroembolic renal failure is reviewed and the efficacy of combined therapy by use of corticosteroids and plasma exchange is evaluated.


Subject(s)
Embolism, Cholesterol/therapy , Glucocorticoids/therapeutic use , Methylprednisolone/therapeutic use , Plasma Exchange , Prednisolone/therapeutic use , Prednisone/therapeutic use , Renal Circulation , Acute Kidney Injury/etiology , Aged , Embolism, Cholesterol/complications , Evaluation Studies as Topic , Fatal Outcome , Humans , Male , Middle Aged
5.
Intern Med ; 39(9): 715-9, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10969902

ABSTRACT

OBJECTIVE: The diagnosis of amyloidosis still relies on biopsy, but there has been a growing demand for the development of a specific noninvasive diagnostic technique. Hepatocyte growth factor (HGF) acts on a variety of epithelial cells in multiple ways and is predominantly produced by mesenchymal cells and macrophages. In the present study, we measured the serum HGF level in patients with amyloidosis and investigated its usefulness for the diagnosis of this disease. METHODS: The subjects were 18 patients diagnosed as having amyloidosis by biopsy. We also measured serum HGF in 47 patients with chronic glomerulonephritis, 32 patients on hemodialysis, and 24 healthy volunteers. The serum HGF level was measured using an HGF ELISA kit. RESULTS: The serum HGF level of patients with amyloidosis was significantly increased compared with that of healthy volunteers, patients with chronic glomerulonephritis, and hemodialysis patients (2.26+/-2.73 ng/ml versus 0.20+/-0.04 ng/ml, 0.23+/-0.08 ng/ml, and 0.18+/-0.07 ng/ml respectively, p<0.0001). There was no significant difference between amyloid light-chain and amyloid A amyloidosis, but the serum HGF level of amyloidosis patients who died within 1 year of measurement was significantly higher than that of patients who lived for more than 1 year (2.83+/-2.85 ng/ml versus 0.49+/-0.26 ng/ml, p<0.01). CONCLUSIONS: The serum HGF level was significantly elevated in both amyloid light-chain and amyloid A amyloidosis and was a very useful indicator of suspected amyloidosis as well as a potential prognostic indicator. The serum HGF level may become a useful indicator for diagnosing amyloidosis.


Subject(s)
Amyloidosis/blood , Gastrointestinal Diseases/blood , Glomerulonephritis/blood , Hepatocyte Growth Factor/blood , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/blood , Chronic Disease , Enzyme-Linked Immunosorbent Assay , Female , Glomerulonephritis/therapy , Humans , Male , Middle Aged , Renal Dialysis
6.
Nephron ; 85(1): 81-5, 2000 May.
Article in English | MEDLINE | ID: mdl-10773760

ABSTRACT

BACKGROUND/AIM: Interleukin-6 (IL-6) promotes the growth of renal mesangial cells. IL-6 may play a major role in such mesangial proliferation, but there has been little research on IL-6 in relation to diabetic nephropathy because of the difficulty in measuring urinary and serum IL-6 levels. Using a newly developed, highly sensitive IL-6 assay, we studied the relationship between serum and urinary IL-6 and diabetic nephropathy. METHODS: We investigated 72 patients with type 2 diabetes. Urinary and serum IL-6 concentrations were measured using a chemiluminescent enzyme immunoassay with a detection limit of 0.11 pg/ml. RESULTS: There was a significant increase of the serum IL-6 level as diabetic nephropathy progressed, with the level being 1.4 +/- 0.3 pg/ml in patients with normal albuminuria, rising to 2.4 +/- 0.6 pg/ml in patients with microalbuminuria and then to 4.4 +/- 0.8 pg/ml in those having proteinuria. The serum IL-6 level was also significantly correlated with fibrinogen and aortic pulse wave velocity. The urinary IL-6 level was also significantly increased in diabetic patients as nephropathy progressed. Both serum and urinary IL-6 levels were high in the group with nephropathy, but there was no correlation between the two. CONCLUSION: The urinary IL-6 level seems to be a good indicator of diabetic nephropathy, and atherosclerotic changes were related to the serum IL-6 level. The serum IL-6 may, therefore, be useful in the evaluation of atherosclerosis including nephropathy.


Subject(s)
Diabetic Nephropathies/blood , Diabetic Nephropathies/urine , Immunoassay/methods , Interleukin-6/blood , Interleukin-6/urine , Albuminuria/blood , Albuminuria/urine , Arteriosclerosis/blood , Arteriosclerosis/urine , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/urine , Female , Humans , Luminescent Measurements , Male , Middle Aged , Predictive Value of Tests , Sensitivity and Specificity
7.
Nihon Jinzo Gakkai Shi ; 42(2): 53-9, 2000 Feb.
Article in Japanese | MEDLINE | ID: mdl-10771576

ABSTRACT

Cholesterol arterial embolization is a systemic disease resulting from cholesterol crystal embolization to multiple organs, including the kidney, skin, brain, eye, gastrointestinal tract and extremities. In general, it is associated with high morbidity and mortality, but no optimal treatment has yet been developed. In this paper, we report five patients with cholesterol atheroembolic renal failure. In three of the five patients, combined therapy with corticosteroids and plasma exchange was performed. The three patients survived. On the other hand, the two remaining patients died of multifactorial causes. In this report, the literature on steroid therapy for cholesterol atheroembolic renal disease is reviewed and the efficacy of combined therapy by use of corticosteroids and plasma exchange is evaluated.


Subject(s)
Acute Kidney Injury/therapy , Anti-Inflammatory Agents/therapeutic use , Embolism, Cholesterol/therapy , Methylprednisolone/therapeutic use , Plasma Exchange , Prednisolone/therapeutic use , Aged , Fatal Outcome , Humans , Male , Middle Aged , Treatment Outcome
8.
Nihon Jinzo Gakkai Shi ; 42(2): 66-72, 2000 Feb.
Article in Japanese | MEDLINE | ID: mdl-10771578

ABSTRACT

The patients was a 43-year-old woman whose chief complaints were nausea and heaviness of the heads. There was a history of toxemia of pregnancy. The patient had previously taken Tenshin Tokishigyaku-ka-goshuyu-shokyo-to for two years because of cold sensitivity. Fever, thirst, and loss of appetite developed from approximately 18 months after she started treatment with the Chinese herbal preparation, and she presented at our outpatient clinic 2.5 years later. On initial examination, deterioration of renal function was evident and the serum creatinine level was 3.4 mg/dl. A renal biopsy specimen showed marked interstitial fibrosis without inflammatory cell infiltration, leading to the diagnosis of Chinese herbs nephropathy (CHN). Steroid therapy was started on the 36th hospital day after a sharp rise in the serum creatinine level to 5.1 mg/dl. This resulted in the rapid improvement of renal function and reduction of the serum creatinine to 2.6 mg/dl by 8 weeks after the initiation of treatment. In a study on the use of steroids for patients with progressive moderate renal dysfunction caused by Chinese herbs, Vanherweghem et al. reported that the progression of renal failure was appreciably slowed in patients given steroids when compared with the control group. We were also able to slow the progression of renal dysfunction in our patient by steroid therapy, although the prognosis of CHN is generally considered to be very poor.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Drugs, Chinese Herbal/adverse effects , Nephritis, Interstitial/chemically induced , Nephritis, Interstitial/drug therapy , Prednisolone/therapeutic use , Adult , Disease Progression , Female , Humans , Kidney/pathology , Nephritis, Interstitial/pathology , Treatment Outcome
10.
Biochem Biophys Res Commun ; 248(3): 858-63, 1998 Jul 30.
Article in English | MEDLINE | ID: mdl-9704018

ABSTRACT

A series of derivatives of mitomycin C conjugated with various fatty acids at position 1a was synthesized and the effect of these compounds on protein kinase activities was evaluated. 1a-Docosahexaenoyl mitomycin C (DMMC) selectively inhibited protein tyrosine kinase (PTK) activity in the postnuclear fraction of v-src-transformed NIH 3T3 cells although neither derivatives conjugated with other fatty acids or docosahexaenoic acid or mitomycin C did not. DMMC inhibited the activity of calmodulin-dependent kinase III and protein kinase A very weakly, and only barely affected protein kinase C activity. DMMC also attenuated autophosphorylation of immunoprecipitated p60v-src irreversibly. The addition of thiol compounds to the reaction mixture reversed the inhibition by DMMC, suggesting that some thiol moiety of PTK protein might be involved. DMMC also inhibited kinase activity of p210bcr-abl immunoprecipitated from the lysate of K562 cells. These results indicate that DMMC is a novel inhibitor of PTK.


Subject(s)
Docosahexaenoic Acids/chemical synthesis , Docosahexaenoic Acids/pharmacology , Enzyme Inhibitors/pharmacology , Mitomycins , Protein-Tyrosine Kinases/antagonists & inhibitors , 3T3 Cells , Animals , Cell Line, Transformed , Docosahexaenoic Acids/chemistry , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Genes, src , Kinetics , Mice , Mitomycin/chemical synthesis , Mitomycin/chemistry , Mitomycin/pharmacology , Models, Molecular , Molecular Conformation , Molecular Structure , Oncogene Protein pp60(v-src)/biosynthesis , Oncogene Protein pp60(v-src)/metabolism , Phosphorylation , Protein Kinases/metabolism , Structure-Activity Relationship
11.
Intern Med ; 37(6): 500-3, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9678681

ABSTRACT

Urinary pancreatic stone protein (PSP) levels were measured in 68 diabetic patients and 170 healthy controls to investigate the relationship between the progression of diabetic nephropathy and PSP excretion. Urinary albumin, N-acetyl-beta-glucosaminidase (NAG), alpha1-microglobulin, creatinine clearance, and the blood PSP level were also determined in the diabetic patients. The urinary glucose level and glycemic control did not influence the urinary PSP level. In patients with normoalbuminuria (urinary albumin <20 mg/gCr, n=31), microalbuminuria (20-200 mg/Cr, n=19), and macroalbuminuria (>200 mg/gCr, n=18), the mean urinary PSP level was 347, 507, and 860 microg/gCr, respectively. These levels were significantly higher than the level in normal volunteers (168 microg/gCr, p<0.01). A significant positive correlation was observed between the urinary PSP level and the NAG or alpha1-microglobulin levels (p<0.01). There was a stronger correlation with alpha1-microglobulin. Blood PSP levels were also elevated in patients who had renal impairment with a decreased creatinine clearance. In conclusion, urinary PSP excretion was increased from the initial stage of diabetic nephropathy and this increase became more marked as nephropathy progressed. Increased PSP excretion may reflect renal tubular dysfunction.


Subject(s)
Calcium-Binding Proteins/urine , Diabetic Nephropathies/urine , Nerve Tissue Proteins , Acetylglucosaminidase/urine , Adult , Aged , Aged, 80 and over , Albuminuria/urine , Alpha-Globulins/urine , Calcium-Binding Proteins/blood , Case-Control Studies , Creatinine/urine , Diabetic Nephropathies/blood , Diabetic Nephropathies/etiology , Female , Glycosuria/urine , Humans , Lithostathine , Male , Middle Aged , Reference Values
12.
Nihon Rinsho Meneki Gakkai Kaishi ; 20(3): 184-90, 1997 Jun.
Article in Japanese | MEDLINE | ID: mdl-9256611

ABSTRACT

UNLABELLED: Splenectomized patients are likely to suffer from severe infections, such as sepsis and meningitis. This syndrome is called overwhelming postsplenectomy infection (OPSI) in Europe and America. The course is rapid, the clinical symptoms are serious, and the prognosis is very poor. We treated one adult patient with OPSI syndrome that developed 10 years after splenectomy. CASE: A 26-year-old man had undergone a splenectomy following a traffic accident 10 years previously. On January 7, 1996, he had diarrhea and nausea. On January 10, he became drowsy and presented at our hospital with multiple organ failure. He underwent hemodialysis and plasmapheresis because of acute renal failure and also received immune globulin, antibiotics and prednisolone. However, these medications were not effective. He died 7 hours later. We identified diplococcus on a blood smear, IgG 3 deficiency and a low titer of specific pneumococcal IgG 2 antibody. The autopsy findings included bilateral acute hemorrhagic necrosis of the adrenal glands (Waterhouse-Friderichsen syndrome).


Subject(s)
Infections/etiology , Splenectomy/adverse effects , Adult , Fatal Outcome , Humans , Male , Postoperative Complications , Time Factors , Waterhouse-Friderichsen Syndrome/etiology
16.
Nephron ; 69(4): 380-3, 1995.
Article in English | MEDLINE | ID: mdl-7777100

ABSTRACT

We studied complexes composed of C1q and beta 2-microglobulin (C1q.beta 2M) or serum amyloid P-component (C1q.SAP) in the sera of 38 patients receiving hemodialysis (HD) and 20 healthy control subjects using an enzyme-linked immunoassay. We also compared complex levels in HD patients with and without symptoms of HD-associated amyloidosis (HA). Serum C1q-beta 2M levels were significantly higher in HD patients without HA than in healthy control subjects and significantly higher in HD patients with HA than in HD patients without HA. Serum C1q.SAP levels were significantly lower in patients with HA than in those without HA. These results suggest that C1q.beta 2M may contribute to HA.


Subject(s)
Amyloidosis/blood , Amyloidosis/etiology , Complement C1q/metabolism , Renal Dialysis/adverse effects , Serum Amyloid P-Component/metabolism , beta 2-Microglobulin/metabolism , Amyloidosis/diagnosis , Female , Humans , Male , Middle Aged , Time Factors
17.
Biochim Biophys Acta ; 1212(2): 211-6, 1994 May 13.
Article in English | MEDLINE | ID: mdl-8180247

ABSTRACT

In our previous report (Shikano, M., Masuzawa, Y. and Yazawa, K. (1993) J. Immunol. 150, 3525-3533), we described that the enrichment of docosahexaenoic acid (DHA, 22:6(n - 3)) reduces both arachidonic acid (AA, 20:4(n - 6)) release and platelet-activating factor (PAF) synthesis in human eosinophilic leukemia cells, Eol-1. Since no DHA release was observed in response to Ca-ionophore stimulation, we presumed that the phospholipase A2 (PLA2) responsible for AA release and PAF synthesis can not hydrolyze the DHA moiety of phospholipids. In the present paper, we examined whether DHA-containing diacyl- and alkenylacylglycerophosphoethanolamine (DHA-diacylGPE and DHA-alkenylacyGPE) are susceptible to the action of AA-preferential 85 kDa cytosolic phospholipase A2 (cPLA2) from rabbit platelets in comparison with AA and eicosapentaenoic acid (EPA, 20:5(n - 3)) derivatives. When diacylGPE was used as a substrate, DHA release was almost negligible under the assay condition that allowed AA and EPA to be liberated at the rates of 4.3 mumol/min per mg protein and 2.5 mumol/min per mg protein, respectively. On the other hand, 14 kDa type II PLA2 hydrolyzed DHA-diacylGPE as well as AA-diacylGPE and EPA-diacylGPE. When DHA-diacylGPE and AA-diacylGPE were mixed at equimolar concentrations, DHA release by cPLA2 was not observed and AA release was reduced to 32% in the case without DHA-diacylGPE. This indicated that DHA-diacylGPE is a poor substrate but possesses the inhibitory activity for cPLA2. cPLA2 does not clearly discriminate between AA-alkenylacylGPE and AA-diacylGPE. As in the case using diacylGPE as a substrate, DHA-alkenylacylGPE was completely discriminated from AA-alkenylacylGPE by cPLA2. The roles of DHA and cPLA2 in the synthesis of lipid mediators will be discussed in relation to the new aspects of the substrate specificity of cPLA2 provided here.


Subject(s)
Arachidonic Acid/metabolism , Docosahexaenoic Acids/metabolism , Phosphatidylethanolamines/metabolism , Phospholipases A/metabolism , Plasmalogens/metabolism , Animals , Eicosapentaenoic Acid/metabolism , Hydrolysis , Phospholipases A/antagonists & inhibitors , Phospholipases A2 , Rabbits , Substrate Specificity , Time Factors
18.
J Immunol ; 150(8 Pt 1): 3525-33, 1993 Apr 15.
Article in English | MEDLINE | ID: mdl-8468486

ABSTRACT

Human eosinophilic leukemia (Eol-1) cells were examined for their ability to generate platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) (PAF) and the effect of supplementation of docosa-hexaenoic acid (C22:6n-3) (DHA) on the PAF synthesis was explored in relation to the fatty acid composition of phospholipids and the liberation of arachidonic acid (C20:4n-6 AA). Although undifferentiated cells did not produce PAF, the exposure of IFN-gamma differentiated Eol-1 to generate PAF in response to the Ca-ionophore. In addition, the IFN-gamma-treated cells acquired the ability to release free fatty acids, approximately 55% of which was found to be AA. When DHA was supplemented into the culture of Eol-1 for 24 h, PAF production decreased by 40 to 50% at concentrations of 3 to 10 microM. On the other hand, supplementation of 10 microM eicosapentaenoic acid (C20:5n-3) did not significantly decrease PAF production. With the supplementation of 10 microM DHA, DHA levels in phospholipid subclasses, including alkylacylglycerophosphocholine, were greatly increased with concurrent decreases in other unsaturated fatty acids. In these cells, the liberation of AA in response to an ionophore was decreased by 55%. Even when DHA was enriched in phospholipids, DHA release in response to ionophore stimulation was almost negligible, indicating that the DHA moiety of phospholipids is not susceptible to the action of phospholipase A2. Furthermore, DHA supplementation appeared to attenuate phospholipase A2 reaction by some unknown mechanism because the decrease in AA release was much more than that for the AA level in phospholipids. Acetyl-CoA:1-alkylGPC acetyltransferase activity of stimulated cell lysate was also reduced by DHA supplementation but the reduction was much less when compared with that of PAF synthesis or AA release. These results implicated that enrichment of DHA attenuates enzymic reactions for PAF synthesis, mainly the initial reaction catalyzed by AA-specific phospholipase, and thereby reduces PAF synthesis in Eol-1.


Subject(s)
Docosahexaenoic Acids/pharmacology , Eosinophils/metabolism , Leukemia, Eosinophilic, Acute/metabolism , Platelet Activating Factor/biosynthesis , Acetyltransferases/metabolism , Arachidonic Acid/metabolism , Calcimycin/pharmacology , Fatty Acids, Nonesterified/metabolism , Humans , Interferon-gamma/pharmacology , Phosphatidylcholines/chemistry , Phosphatidylethanolamines/chemistry , Tumor Cells, Cultured
19.
Intern Med ; 31(7): 917-21, 1992 Jul.
Article in English | MEDLINE | ID: mdl-1450502

ABSTRACT

The first case of Klinefelter's syndrome accompanied by diabetes insipidus and diabetes mellitus is reported. A 41-year-old man admitted for hyperosmolar diabetic coma with a past history of diabetes insipidus was diagnosed as having Klinefelter's syndrome by endocrinological examination and sex chromosome analysis. In this case, glucose tolerance test was normalized half a year later and blood glucose was well controlled with diet therapy alone.


Subject(s)
Diabetes Insipidus/etiology , Diabetes Mellitus, Type 2/etiology , Klinefelter Syndrome/complications , Adult , Diabetes Insipidus/diagnostic imaging , Diabetes Insipidus/epidemiology , Diabetes Mellitus, Type 2/epidemiology , Humans , Incidence , Japan/epidemiology , Karyotyping , Klinefelter Syndrome/blood , Klinefelter Syndrome/epidemiology , Male , Radiography
20.
Eur J Biochem ; 201(3): 607-14, 1991 Nov 01.
Article in English | MEDLINE | ID: mdl-1657602

ABSTRACT

A series of analogs of eel calcitonin (eCT) was synthesized according to a newly devised scheme, 'the insertion-inactivation method', to clarify the structure/activity relationship of a given peptide. This method consists of two steps: the deletion of a residue of the peptide is first chosen and then a series of analogs with the residue reinserted into serial positions is synthesized and biological activities are assessed in each step. An analog lacking Lys18 (dK), selected as a deleted analog for the first step, showed marked loss of activities determined by inhibition of 125I-eCT binding, growth inhibition, and cAMP production in a porcine kidney cell line LLC-PK1. Activities of a set of 20 analogs with the reinserted lysine residue at serial positions from 12 to 32 (K12-K32) were then evaluated. The results showed the following three patterns of the expression of activities according to the position of the reinsertion: (a) analogs K12-K16 (positions 12-16) and K25 (position 25) showed lower activities than eCT in all assays; (b) K17-K24 (positions 17-24) showed slightly lower activities than eCT in the receptor binding and the growth inhibition and similar level in cAMP production; (c) K26-K32 (positions 26-32) showed considerably lower activities in the former two assays and slightly lower activity in cAMP production. Further, analogs considerably less active than eCT showed unchanged alpha-helix contents and destroyed amphiphilicity by the insertion of a lysine residue, indicating that amphiphilicity is one of important factors for expressing the activity. The results obtained here lead to a conclusion on the significance of each region of eCT molecule as follows: (a) the presence of Lys18 is necessary for the complete expression of biological activity; (b) the length of amphiphilic alpha-helix to be required for the activity is at most 10 residues ranging from position 8 to position 17; (c) the receptor binding region is located within 9 residues ranging from position 24 to position 32.


Subject(s)
Calcitonin/physiology , Amino Acid Sequence , Animals , Calcitonin/analogs & derivatives , Calcitonin/chemical synthesis , Calcitonin/pharmacology , Cell Division/drug effects , Cell Line , Chemical Phenomena , Chemistry, Physical , Circular Dichroism , Cyclic AMP/biosynthesis , Eels , Lysine , Molecular Sequence Data , Receptors, Calcitonin , Receptors, Cell Surface/metabolism , Structure-Activity Relationship
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