Synthesis and secretion of human epidermal growth factor by Escherichia coli.

A synthetic gene for human epidermal growth factor (hEGF) was joined to a sequence encoding the signal peptide of Escherichia coli alkaline phosphatase. This hybrid gene was placed under the control of the alkaline phosphatase gene (phoA) promoter in a recombinant plasmid, which was used to transfect E. coli. The hybrid protein that was expressed in host cells under conditions of phosphate limitation was processed accurately during the secretion process, and mature hEGF was recovered in the periplasmic fraction. On the other hand, no EGF was detected in the periplasmic space when the synthetic hEGF gene was not accompanied by the phoA signal sequence.     

Glucocorticoid regulates secretion of epidermal growth factor in the human salivary gland adenocarcinoma cell line

The treatment of a human submandibular gland adenocarcinoma cell line (HSG cell line) for 48 h with triamcinolone acetonide (TA; 1-100 nmol/l) reduced the secretion of epidermal growth factor (EGF) in a closely related manner to a maximum of 66%. The reduction in the level of EGF secreted resulted in the suppression of DNA synthesis in the HSG cells to a similar extent. When the cells were incubated with TA and exogenous human EGF (hEGF), DNA synthesis was 1.7-fold higher than that without added hEGF. The removal of EGF by the addition of hEGF antibody reduced DNA synthesis in HSG cell cultures to the same extent as did TA. These results suggest that the growth inhibition of HSG cells by TA is due to the reduction in the amount of EGF secreted.     

Release and action of epidermal growth factor on gastric secretion in humans

Epidermal growth factor (EGF) has recently been localized in salivary, pancreatic, and Brunner's glands in humans, but little is known about its release and its action on gastric secretion. This study, performed on healthy subjects, was designed to determine the release of immunoreactive EGF in plasma and in salivary and gastric secretions under basal conditions and after modified sham feeding (MSF), ordinary feeding, and infusion of pentagastrin without and with addition of exogenous recombinant human EGF (hEGF). Under basal conditions the EGF concentrations in plasma and salivary and gastric secretions were 52 +/- 8 pg/ml, 2.5 +/- 0.3 ng/ml, and 0.12 +/- 0.03 ng/ml, respectively. MSF and ordinary feeding increased significantly EGF plasma level and salivary output but not gastric EGF output, and atropinization failed to effect these plasma and salivary EGF responses to MSF. Intravenous infusion of pentagastrin increased both plasma and salivary but not gastric EGF, and addition of exogenous hEGF in graded doses (0.25-1.0 micrograms/kg) resulted in a dose-dependent increase in the plasma level of EGF and in significant inhibition of gastric acid and pepsin outputs. The increment in plasma EGF, which resulted in significant inhibition of gastric secretion, was several times greater than that observed after MSF or feeding. EGF infused in a constant dose (0.12 or 1.0 micrograms/kg-h) resulted in an increment in plasma EGF similar to that observed after MSF alone.     

Biosynthesis of a protein containing a nonprotein amino acid by Escherichia coli: L-2-aminohexanoic acid at position 21 in human epidermal growth factor.

Endeavoring to develop a method to biosynthesize proteins substituted with nonprotein amino acids, we attempted the incorporation of L-2-aminohexanoic acid (Ahx) into human epidermal growth factor (hEGF). Escherichia coli YK537 strain harboring plasmid pTA1522, which has the phoA promoter-phoA signal peptide-hEGF gene, was used. Cells were cultured first in high-phosphate medium and then, for induction of the hEGF-encoding gene, transferred to low-phosphate medium containing Ahx (0.25 mg/ml). hEGF and Ahx-substituted hEGF, [Ahx21]hEGF, secreted into the periplasm were recovered. After treatment with H2O2, [Ahx21]-hEGF was clearly separated from methionine-oxidized hEGF by one-step reverse-phase HPLC. Substitution of the methionine residue of hEGF with Ahx was confirmed by the amino acid analysis of [Ahx21]hEGF. The three biological activities of [Ahx21]hEGF were the same as those of hEGF. From the successful production of [Ahx21]hEGF, a basic strategy was established for preparing proteins substituted with nonprotein amino acid (alloprotein). Induction of the phoA promoter of pho regulon and secretion of the product to the periplasm may depress heat shock-like responses and subsequent hydrolysis of the product by cytoplasmic protease.     

Salivary EGF levels reduced in diabetic patients

Oral problems such as periodontitis are recognized major complications associated with diabetes. Salivary derived growth factors, including epidermal growth factor (EGF), are thought to play a role in helping maintain levels of oral health, promoting wound healing, and maintaining mucosal integrity. In the present study, salivary levels of EGF in diabetic vs. healthy control patients was evaluated. Twenty-one diabetic patients participated in this study. Age, race, sex and smoking histories were matched with 21 systematically healthy nondiabetic patients. Three milliliters of unstimulated resting whole saliva was collected from each patient at 6 h intervals up to 42 h and whole saliva protein concentrations were determined for each sample. EGF concentrations for each sample were quantitated spectrophometrically utilizing an immunoassay. Diabetic patients had greater salivary protein concentrations over 42 h of collection with a mean of 1.502+/-0.09 vs. 1.242+/-0.05 mg/ml for healthy control patients. The EGF concentration was significantly lower (p<0.05) for the diabetic patients compared to control patients, whether expressed relative to 1 ml volume of saliva (873.43+/-106.5 vs. 1101.09+/-116.8 pg/ml) or 1 mg whole saliva protein (629.18+/-92.6 vs. 931.20+/-124.6 pg/mg saliva protein). This study suggests that reduced levels of salivary EGF in diabetic patients may contribute to the development of oral and systemic complications of diabetes, which may have future clinical applications.     

Salivary Epidermal Growth Factor in Patients with and without Acid Peptic Disease

Epidermal growth factor inhibits gastric acid secretion and has a cytoprotective effect on the upper gastrointestinal tract. This study was undertaken to determine whether patients with endoscopically proven active peptic ulcer disease have a salivary deficiency of human epidermal growth factor (hEGF), compared to patients with a normal esophagogastroduodenoscopy (EGD). Saliva was collected from fasting subjects prior to EGD. The levels of EGF were measured by radioimmunoassay. Statistical evaluation was performed by analysis of variant followed by Student's t test. The concentrations of the peptide were lower in patients with active peptic ulcer disease (3.1 +/- 0.54 ng/ml, mean +/- SE, n = 25) compared with normal subjects (4.9 +/- 0.56 ng/ml, n = 58, p less than 0.03). No significant differences in salivary hEGF were noted between patients with a normal EGD and patients with gastritis (3.85 +/- .86 ng/ml, n = 13), esophagitis (4.5 +/- 1.3 ng/ml, n = 7), or Barrett's esophagus (5.3 +/- 1.5 ng/ml, n = 6). There were no differences in the salivary levels of hEGF between males and females, or between smokers and nonsmokers. There was no correlation of hEGF levels with age. The pathophysiologic significance of this finding is uncertain. Lower salivary hEGF may reduce one of the defensive mechanisms responsible for protecting the gastroduodenal mucosa from injury by physicochemical agents, thus contributing to ulcer development.     

Effects of epidermal growth factor and insulin on migration and proliferation of primary cultured rabbit gastric epithelial cells

We assessed the influence of epidermal growth factor (EGF) and insulin on gastric epithelial restoration in vitro. Rabbit gastric epithelial cells were cultured and formed a complete monolayer cell sheet in 2 days. We created a wound (1.8±0.05 mm²) by denuding an area of cells, and EGF (0.1–30 ng/ml) and/or insulin (1nM–1μM) was added. The restoration process, which included cell migration and proliferation, was monitored by measuring the cell-free area every 12 h for 2 days. Proliferating cells were detected by sequential staining with bromodeoxyuridine (BrdU). Control cells showed complete repair in 36–48h and restoration was accelerated dose-dependently by EGF or insulin. EGF plus insulin further accelerated restoration, which was then completed in 12–24h. EGF and/or insulin increased the number of BrdU- positive cells. The results indicated that EGF and insulin additively accelerated gastric epithelial wound repair by stimulating both the migration and the proliferation of gastric epithelial cells (particularly the former).     

Study on distribution of epidermal growth factor (EGF) in rat tissues

Tissue distribution of epidermal growth-factor (EGF) in rat was investigated using a human EGF (hEGF) radioimmunoassay system. Antisera generated against hEGF reacted with hEGF and [21Leu] hEGF but not with mouse EGF, fibroblast growth factor (FGF), nerve growth factor (NGF), platelet derived growth factor (PDGF), and endothelial cell growth supplement (ECGS). Similar amounts of EGF immunoreactivity (EGF-IR) were found in the rat submandibular gland (32.8 +/- 4.59 ng/g tissue, n = 5) and duodenum (39.9 +/- 18.7 ng/g tissue, n = 9), whereas little EGF was detected in other tissues. No sex difference was observed in submandibular and duodenal EGF-IR, being different from the case of mouse in which ten times higher concentration of EGF-IR was found in male submandibular gland. Sephadex G-50 gel chromatography of submandibular and duodenal extracts revealed that each consisted of at least three different immunoreactive forms. The predominant EGF-IR was coeluted with 125I-EGF, significant amounts of EGF-IR was observed in the void volume fractions, and only small peaks of EGF-IR were present near Vt. These data clarified the presence of EGF-IR in rat submandibular and duodenal tissues and the molecular heterogeneity of EGF-IR and suggest some important role of EGF in the gastrointestinal function.     

Direct inhibition of rat granulosa cell inhibin production by epidermal growth factor in vitro

The effect of epidermal growth factor (EGF) on inhibin production by rat granulosa cells has been investigated using a recently developed inhibin radioimmunoassay (RIA). Granulosa cells from intact immature diethylstilbestrol (DES)-treated rats were exposed to EGF (1-100 ng/ml) in the presence or absence of FSH for varying periods in vitro. An inhibitory effect of EGF on basal inhibin secretion was evident at day 2 of culture and was sustained over the subsequent 2 days. This action on basal inhibin secretion was dose-dependent, and maximal inhibition to 50% of control was observed at a dose of 100 ng EGF/ml at day 4. EGF also inhibited basal progesterone secretion in a similar manner. EGF caused a dose-dependent inhibition of FSH-stimulated inhibin secretion, with an ID50 (0.5 ng/ml, 0.08 nM) about one-eighth that in the absence of FSH. In addition, EGF also inhibited the stimulation of inhibin production by 8-Br-cAMP and prostaglandin E2. To exclude the possibility that EGF was toxic to the granulosa cells, several biochemical parameters related to cell growth were measured. EGF treatment did not alter cell number but slightly increased [3H]thymidine incorporation into cellular DNA. The effect of EGF on [35S]methionine incorporation into cellular protein was biphasic, being stimulatory at doses less than 10 ng/ml but inhibitory at 100 ng/ml. The present data have demonstrated a direct inhibitory effect of EGF on basal and FSH-stimulated inhibin production by granulosa cells suggesting an important regulatory role of this growth factor in the differentiation of ovarian function.     

Transforming growth factor-alpha (TGF α)-producing gastric carcinoma with acanthosis nigricans: An endocrine effect of TGF α in the pathogenesis of cutaneous paraneoplastic syndrome and epithelial hyperplasia of the esophagus

A case of well-differentiated adenocarcinoma (Borrmann type 3) of the stomach in a 76-year-old man associated with the typical skin manifestations of acanthosis nigricans and with multiple protruding lesions showing epithelial hyperplasia of the esophagus is reported. The advanced tumor was located in the cardiac region of the stomach, and measured approximately 8cm in diameter, with partial invasion to the esophagus. The associated cutaneous lesions were characterized by hyperpigmentation and by protruding verrucous papules on the torso, head, face, neck, upper extremities, perineum, and inguinal region. Histologically, the protruding skin lesions showed keratinocytes proliferation throughout the epidermis, resulting in diffhyperkeratosis, papillomatosis, and acanthosis of the skin. Immunohistological analysis showed coexpression of transforming growth factor alpha (TGF-a) and epidermal growth factor (EGF) receptors in the tumor from the stomach. It is reasonable to conclude from this evidence that gastric carcinoma cells secrete TGF in an autocrine for auto-stimulation. EGF receptor expression was also noted on the papillomatous hyperplasia of the cutaneous lesion. Serum level of TGF , determined by an enzyme-linked immunosorbent assay, was high (144pg/ml; normal, 22.0 ±16pg/ml (Mean±SD)). Serum TGF abruptly decreased to 49pg/ml on day 7 after the total gastrectomy, and then gradually increased to 77pg/ml within 28 days. Amelioration of the cutaneous lesions and the protruding lesions in the esophagus was observed after surgical resection of the gastric carcinoma. This suggests that the TGF stimulates the proliferation of keratinocytes involved with EGF receptor. Large amounts of circulating TGF in the blood over a long period released by the primary tumor seem to act as an endocrine-like mechanism causing epidermal and esophageal epithelial cells to proliferate. There is a possible link in the pathogenesis of the acanthosis nigricans as a cutaneous paraneoplastic syndrome, and epithelial hyperplasia of the esophagus.     

Appearance of heparin-binding EGF-like growth factor in wound fluid as a response to injury.

Wound fluid was obtained from porcine partial-thickness excisional wounds and analyzed for heparin-binding growth factors. Two heparin-binding growth factor activities were detected, a relatively minor one that was eluted from a heparin affinity column with 0.65 M NaCl and a major one that was eluted with 1.1 M NaCl. These activities were not present in wound fluid 1 hr after injury but appeared 1 day after injury, were maximal 2-3 days after injury, and were not detectable by 8 days after injury. The heparin-binding growth factor eluted with 0.65 M NaCl was identified as a platelet-derived growth factor (PDGF)-like activity by the use of specific anti-PDGF neutralizing antibodies. The heparin-binding growth factor eluted with 1.1 M NaCl was shown to be structurally related to heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) by several criteria, including binding to heparin affinity columns and elution with 1.1 M NaCl, competition with the binding of 125I-EGF to the EGF receptor, triggering phosphorylation of the EGF receptor, immunodetection on a Western blot, and stimulation of fibroblast and keratinocyte growth. It was concluded that HB-EGF is a major growth factor component of wound fluid and, since it is mitogenic for fibroblasts and keratinocytes, that it might play an important role in wound healing.     

Japanese family with glucocorticoid-remediable aldosteronism diagnosed by long-polymerase chain reaction.

We report a Japanese family with glucocorticoid-remediable aldosteronism (GRA) in whom gene abnormality was identified by the long-polymerase chain reaction (PCR) method. The proband was a 21-year-old female incidentally found to have high blood pressure (173/107 mmHg). Laboratory tests showed hypokalemia (3.7 mmol/l), and high plasma aldosterone concentration (PAC, 234 pg/ml) with suppressed plasma renin activity (PRA, <0.1 ng/ml/h). The circadian rhythm pattern and the results of a rapid adrenocorticotrophic hormone (ACTH) test indicated ACTH-dependent changes in PAC. Imaging studies showed no adrenal mass on either side. A dexamethasone (Dexa) suppression test (1.0 mg/day orally for 7 days) showed a marked decrease of PAC 2 days after administration, and this decreased level was maintained throughout Dexa administration. High blood pressure and hypokalemia also improved during Dexa treatment. The proband's younger sister was 19 years old and had hypertension, PAC of 231 pg/ml, and PRA <0.1 ng/ml/h. The mother was 53 years old and had hypertension, PAC of 98.5 pg/ml, and PRA <0.1 ng/ml/h. The proband's elder sister was a 22-year-old normotensive with PAC of 110 pg/ml and PRA of 0.1 ng/ml. Long-PCR was performed for detection of the chimeric gene associated with GRA, using DNA samples from all four cases and two normal control subjects. Although the aldosterone synthase gene was expressed among all DNA samples, the chimeric gene was detected only in the proband, her younger sister and her mother. Our clinical data and genetic investigation confirmed the presence of GRA in this Japanese family.     

Epidermal growth factor alters milk composition and fluid balance of lactating ewes.

Lactating ewes were treated with murine epidermal growth factor (EGF) and its effects on concomitant milk production and composition were observed. Six ewes were infused via the jugular vein with 200 ml saline/day over 4 days (days 9-12 of lactation) followed by EGF at a dose rate of 0.5 mg/day in 200 ml saline over 4 days (days 13-16). All ewes then received a further infusion of 200 ml saline/day over 4 days (days 17-20). During the experiment a maintenance (lactation) diet was offered and ewes were machine-milked twice daily. An EGF-immunoreactive material was detected in mammary secretions and urine throughout the experiment, but only in plasma (1-9 micrograms/l) during the period of EGF infusion. The amount of EGF appearing in milk and urine increased from 37 micrograms and 10 micrograms respectively (day 1 of EGF infusion) to 56 micrograms and 17 micrograms respectively (day 4). EGF treatment resulted in lower milk yield and reduced concentration of lactose and protein; milk fat concentration fell after EGF infusion had ceased. Water intake increased markedly during EGF infusion and was 60% (4 kg) greater on day 4 than that measured during the first saline infusion. Urine volume also increased and was 164% (3.6 kg) greater by day 4 of EGF infusion compared with that recorded in the first saline infusion. Water retention (intake minus output in milk, urine and faeces) was significantly higher on the day after EGF infusion ceased than that found during the first saline infusion. The possibilities that the increased water intake was primary, or secondary, to a diuretic effect of EGF are discussed.     

γ干扰素质粒基因转染对支气管哮喘小鼠气道炎症的影响

目的观察气道内γ干扰素(IFNγ)基因转染对支气管哮喘(简称哮喘)小鼠气道炎症的影响。方法健康6周龄SPF级C57BL/6小鼠40只,按随机数字表法分为4组。正常对照组(A组)、哮喘模型组(B组)、模型空质粒干预组(C组)、模型IFNγ质粒干预组(D组),每组10只。B组、C组及D组以0.1%卵白蛋白(OVA)0.1ml腹腔注射致敏,以1%的OVA50μl滴鼻激发建立哮喘模型;A组用等量生理盐水分别代替0.1%的OVA0.1ml和1%OVA50μl;C组和D组分别经鼻滴入空质粒pcDNA3.1()和Lipofentamine2000混合液50μl或重组IFNγ质粒和Lipofentamine2000混合液50μl。观察各组小鼠支气管肺泡灌洗液(BALF)中的细胞成分、白细胞介素4(IL4)、IL5、IFNγ和肺组织病理学变化。结果B组小鼠BALF中炎性细胞总数、嗜酸粒细胞(EOS)、中性粒细胞和淋巴细胞计数分别为(0.102±0.020)×109/L、(0.0193±0.0047)×109/L、(0.0107±0.0039)×109/L、(0.0255±0.0042)×109/L,A组分别为(0.082±0.012)×109/L、(0.0041±0.0009)×109/L、(0.0051±0.0016)×109/L、(0.0201±0.0019)×109/L,A、B两组比较差异有统计学意义(P<0.05);D组小鼠BALF中炎性细胞总数、EOS、中性粒细胞和淋巴细胞计数分别为(0.086±0.016)×109/L、(0.0116±0.0031)×109/L、(0.0062±0.0018)×109/L、(0.0182±0.0041)×109/L,与B组比较差异有统计学意义(P<0.05)。B组小鼠BALF中IL4、IL5、IFNγ水平分别为[(39.2±5.1)pg/ml、(83.7±4.7)pg/ml、(15.7±2.7)pg/ml],A组小鼠分别为[(13.3±1.9)pg/ml、(12.1±2.3)pg/ml、(31.8±7.9)pg/ml],A、B两组比较差异有统计学意义(P<0.05);D组小鼠BALF中IL4、IL5、IFNγ水平分别为[(16.4±3.2)pg/ml、(26.3±3.4)pg/ml、(65.4±10.4)pg/ml],与B组比较差异有统计学意义(P<0.05)。A组小鼠气道无明显炎症变化,B和C组小鼠小支气管、血管黏膜下和周围肺组织有明显的炎症细胞浸润,血管壁明显水肿;D组小鼠气道炎症明显减轻。结论气道内转染干扰素质粒能有效改善哮喘小鼠细胞因子IL4、IL5和IFNγ异常,同时对EOS、中性粒细胞数和淋巴细胞肺内募集、肺组织炎症改变有一定抑制作用。     

Biologic effects of epidermal growth factor in human fetal jejunum

The influence of epidermal growth factor (EGF) on the differentiation and proliferation of human fetal jejunum was studied in organ cultures. Fetal intestine (11-14-wk gestation) was cultured for 5 days at 37 degrees C in serum-free Leibovitz L-15 medium alone or supplemented with 25, 50, and 100 ng EGF/ml culture medium. The addition of hormone did not modify the morphology of the intestinal explants. Biochemical studies revealed that lactase activity was significantly increased with the addition of 50 and 100 ng EGF/ml culture medium. On the other hand, the increase in sucrase, trehalase, and glucoamylase activities that normally occurs during the culture was repressed in the presence of increasing concentrations of EGF. Deoxyribonucleic acid synthesis was significantly decreased after 5 days of culture even in the presence of the lowest EGF concentration used. Concomitantly, the labeling index of the epithelial cells dropped drastically in the presence of EGF. The EGF-induced variation in DNA synthesis was already evident within 24 h of culture, whereas enzymic modifications occurred only between the third and fifth day of culture. The simultaneous addition of EGF and hydrocortisone (50 ng/ml) did not reveal any synergistic action between the two hormones on the hydrolytic activities of the brush border. However, EGF did inhibit hydrocortisone-stimulated DNA synthesis. The present work provides for the first time some basic data on the influence of EGF on brush border hydrolytic activities and on epithelial cell proliferation of human fetal jejunum. These observations strongly suggest that EGF plays an important role in the fetal development of the human gastrointestinal tract.     

Role of salivary and seric epidermal growth factor in pathogenesis of reflux esophagitis in chronic alcoholics and nondrinkers

Our objective was to investigate the putative role of epidermal growth factor (EGF) in esophagitis pathogenesis in both nondrinkers and chronic alcoholics. We studied the EGF serum level, the EGF salivary concentration, and the esophageal EGF receptor expression in different groups of patients with esophagitis: nondrinkers with typical symptoms of gastroesophageal reflux (N=12) and chronic alcoholics (N=12), and in controls: chronic alcoholics without esophagitis (N=16) and healthy nondrinkers (N=12). All patients had an endoscopy with esophageal biopsies, 24-hr esophageal pH-metry, and esophageal manometry. EGF serum levels and EGF salivary concentrations were determined by radioimmunoassay. EGF receptor expression was determined by immunohistochemistry. Both the EGF serum level and the EGF salivary concentration remained constant, 328±21 pg/ml and 305±48 pg/ml, respectively, regardless of alcohol intake and the presence or absence of esophagitis. In addition, the presence of esophagitis did not affect the EGF receptor expression. These results suggest that seric and salivary EGF is not involved in the pathogenesis of reflux esophagitis in nondrinkers and in chronic alcoholics.     

鼠白细胞介素12质粒对小鼠支气管哮喘模型气道炎症及细胞因子的影响

目的　研究鼠白细胞介素 12 (IL 12 )基因表达 (mIL 12 )质粒对小鼠支气管哮喘 (简称哮喘 )模型气道炎症及细胞因子的影响 ,并分析其作用机制。方法　卵白蛋白 (OVA)致敏建立小鼠哮喘模型。BALB/c小鼠 4 1只 ,分为 6组。即哮喘模型组 (A组 ) 8只 :OVA致敏 +OVA气雾攻击 ;模型对照组 (B组 ) 6只 :用生理盐水代替 1%OVA溶液雾化 ,余处理同A组 ;mIL 12质粒预防组 (C组 ) 8只 :实验第 1、3、5天各肌肉注射mIL 12质粒 10 0 μg ;mIL 12质粒治疗组 (D组 ) 8只 :实验第 14、16、18天各肌肉注射mIL 12质粒 10 0 μg ;空质粒预防组 (E组 ) 5只 :实验第 1、3、5天各肌肉注射空质粒 10 0 μg ;空质粒治疗组 (F组 ) 6只 :实验第 14、16、18天各肌肉注射空质粒 10 0 μg。测定所有小鼠支气管 肺泡灌洗液 (BALF)中的嗜酸粒细胞 (EOS)个数和IL 4、IL 5、γ干扰素 (IFN γ)水平。结果B组小鼠EOS个数和IL 4、IL 5、IFN γ浓度分别为 (0 0 1± 0 0 3)× 10 8/L、(2 4± 4 ) pg/ml、(33± 6 ) pg/ml、(72 5± 5 9) pg/ml,C组为 (0 0 6± 0 0 4 )× 10 8/L、(43± 13) pg/ml、(6 3± 10 )pg/ml、(6 2 6± 6 0 ) pg/ml,D组为 (0 11± 0 12 )× 10 8/L、(38± 14 )pg/ml、(6 6± 14 ) pg/ml、(6 6 1± 4 0 ) pg/ml,与A     

Measurement of urinary epidermal growth factor by radioimmunoassay and its application

Epidermal growth factor (EGF), a polypeptide hormone originally discovered in the mouse submaxillary gland, stimulates growth in a variety of tissues in several species. This hormone has recently been identified in human urine. Herein, radioimmunoassay (RIA) for human EGF (hEGF) has been developed, using human recombinant EGF as reference standard and radioiodinated tracer and antibodies raised against hEGF. Its sensitivity was somewhat higher than that of RIAs reported formerly. This method had no cross reactivity with high molecular weight EGF. Urinary concentrations of hEGF in normal males and females were 30.2 +/- 13.0 ng/mg creatinine and 46.4 +/- 17.4 ng/mg creatinine, respectively. Urinary concentration of hEGF in patients with renal cancer was somewhat low. The patients with bladder cancer had lower urinary excretion of hEGF than normal adults (p less than 0.05). However, the role of hEGF in health and disease remains to be determined.     

Gastric juice immunoreactive epidermal growth factor levels in patients with peptic ulcer disease

Immunoreactive epidermal growth factor (IR-EGF) was measured by a highly sensitive and specific radioimmunoassay in gastric juice samples obtained during endoscopy from 26 control subjects, 44 patients with duodenal ulcers, and 18 with benign gastric ulcers. In the active stage, the concentrations of the peptide were consistently reduced, compared with those found in control subjects (592.7 +/- 55.8 pg/ml), in both duodenal (262.6 +/- 21.4 pg/ml) and gastric ulcer patients (320.2 +/- 34.1 pg/ml) (p less than 0.001 and 0.01, respectively). Mean IR-EGF values distinctly lower than in the controls were still present in the gastric juice of patients with inactive duodenal ulcers (349.7 +/- 35.9 pg/ml; p less than 0.001), whereas no difference was observed in patients with healed gastric ulcers (502.2 +/- 132.3 pg/ml). Although these findings suggest a possible role for EGF deficiency in the pathogenesis of peptic ulcer disease, the pathophysiological significance of our results (if any) remains to be elucidated.