[Acupuncture with smoothing liver and regulating qi for post-stroke slow transit constipation and its gastrointestinal hormone level].

OBJECTIVE: To compare the efficacy between acupuncture with smoothing liver and regulating qi and lactulose for post-stroke slow transit constipation(STC) and to explore the mechanism. METHODS: Sixty patients were randomized into an acupuncture group and a medication group,30 cases in each one. Based on the comprehensive stroke unit care,acupuncture with smoothing liver and regulating qi was used at Danzhong(CV 17),Qihai(CV 6),Tianshu(ST 25),Neiguan(PC 6),Gongsun(SP 4) and Taichong(LR 3) in the acupuncture group,once a day. Lactulose oral liquid was taken at a draught in the morning in the medication group,20 to 30 mL a time,once a day. The study period was 11 weeks,including 1-week baseline evaluation,6-week treatment and 4-week follow-up. We recorded the time of the first independent defecation,constipation symptom score,and gastrointestinal hormone level,including somatostatin(SS),motilin(MTL),P substance(SP) and vasoactive intestinal peptide(VIP). Also,the side effects were recorded at any time. RESULTS: The time of the first independent defecation was (30.18±16.14) h in the acupuncture group,which was significantly different from (43.22±28.42) h in the medication group(P<0.05). The constipation scores after 6-week treatment and at follow-up were lower than those before treatment in the two groups (all P<0.05),with better results in the acupuncture group(both P<0.05). MTL and SP increased,as well as SS and VIP decreased after treatment in the two groups(all P<0.05). The changes were better in the acupuncture group(all P<0.05). The side effect was not observed in the two groups. CONCLUSIONS: Acupuncture with smoothing liver and regulating qi achieves better effect than lactulose for post-stroke STC in terms of efficacy onset,extent,and long term. The mechanism may relate to increasing excitatory regulatory peptide and reducing inhibitory regulatory peptide.

[Clinical Feature in Infants of Breast Feeding Allergy and Its Possible Relation with Gastrointestinal Peptide Change in Breast Milk].

OBJECTIVES: To investigate clinical features in infants of breast milk allergy(BMA), and the possible relationship with the changes of somatostatin (SST) and motilin (MTL) in breast milk. METHODS: Twenty three cases of pure breast feeding infants with allergic gastroenteritis were collected, while another 23 normal infants with pure breast feeding were enrolled as normal controls. Samples of infant stools and breast milk were collected for the measurement of SST and MTL levels detected by by radioimmunity. RESULTS: The levels of SST and MTL in stool samples (pg/mg) were 32.6±8.9, 2.3±3.7 in BMA group and 56.2±12.7, 21.6±4.7 in normal control group, respectively. Those in breast milk (pg/mg) were 236.7±28.9, 159.4±36.7 in BMA group and 412.6±36.7, 216.8±59.7 in normal control group, respectively. All the differences were statistically significant ( P<0.05). In BMA infants, the clinical features were 91.3% (20/23) of diarrhea, 86.9% (21/23) of vomiting, 69.6% (16/23) of hematochezia, 95.7% (22/23) of C-reactive protein (CRP) increasing, 87.0% (20/23) of occult blood in stools, 73.9% (17/23) of neutrophil increasing, 39.1% (9/23) of WBC in stools. CONCLUSIONS: For those infants of breast feeding with persisting and repeated gastrointestinal symptoms, allergy for breast milk should be considered. Deficiency of SST and MTL in breast milk may be a possible cause for food allergy.

Gut peptide profile and chemotherapy-associated dyspepsia syndrome in patients with breast cancer undergoing FEC60 chemotherapy.

AIM: The association of motilin, ghrelin, leptin, gastrin, pepsinogen (PG) I and II with cancer chemotherapy-associated dyspepsia syndrome (CADS) was investigated in 35 patients with breast cancer receiving first cycle of 5-fluorouracil, cyclophosphamide, epirubicin (FEC60) chemotherapy. PATIENTS AND METHODS: The onset of dyspeptic symptoms on days 3 and 10 after chemotherapy identified patients with and without CADS. Gastrointestinal symptoms were scored with the Gastrointestinal Symptom Scoring Rate (GSRS) questionnaire. Gastrointestinal peptides were evaluated by enzyme-linked immunosorbent assay. RESULTS: Twenty-one patients (60%) had CADS. The area under the curve (AUC) of ghrelin was higher, whereas that of PGI, PGII and motilin were lower in patients with CADS compared to those without. In patients with CADS, the AUC of PGI and PGII negatively correlated with the GSRS indigestion cluster. CONCLUSION: Impairment of gastrointestinal motility suggested by low motilin concentrations and mucosal damage mirrored by an increase of ghrelin seem to be involved in the onset of CADS in patients during chemotherapy for breast cancer.

An immunocytochemical study of the endocrine cells in the stomach and duodenum of Zonotrichia capensis subtorquata (Passeriformes, Emberizidae).

The main purpose of this study was to evaluate the regional distribution pattern and relative frequency of some endocrine cells in the three portions of the gastrointestinal tract (GIT)--the proventriculus, gizzard and duodenum- of the rufous-collared sparrow (Zonotrichia capensis subtorquata), by immunohistochemical methods using six types of polyclonal antisera, specific for serotonin (5-HT), somatostatin (D cells), glucagon, motilin, polypeptide YY (PYY) and insulin. In the proventriculus, endocrine cells immunoreactive for all of these markers were observed. The somatostatin-immunoreactive cells were found with greater frequency, with the presence of cytoplasmic processes. In the gizzard, endocrine cells secreting somatostatin, 5-HT and PYY were detected, while those secreting glucagon and insulin were not. In the final part of the gizzard, endocrine cells secreting 5-HT were more frequent, and cells secreting somatostatin and insulin were not detected. All of the cell types studied were observed in the duodenum in different frequencies, except for cells immunoreactive for glucagon and insulin. The somatostatin-positive (D cells) were the most numerous, being more prevalent in the intestinal glands. The other endocrine cells were identified in smaller numbers, some of them located in the intestinal villi and Lieberkuhn glands. The finding of these cell types in the duodenum confirms their preferential location in the final portions of the principal segments of the digestive system and suggests control by feedback of its functions. In conclusion, some interesting distributional patterns of gastrointestinal endocrine cells were found in this species of sparrow.

[Clinicopharmacological study of gastrointestinal drugs from the viewpoint of postmarketing development].

Pharmaceutical development starts with the discovery of a new compound. Drugs become commercially available after non-clinical and clinical studies, but processes that take place after marketing are also important for pharmaceutical development. In recent years, use of the phrase "Ikuyaku" meaning postmarketing development has become more common. Sometimes, the proper usage, indications and harmful effects of a drug are discovered only after it becomes commercially available and is administered to many patients. Hence, pharmacists need to actively perform postmarketing studies to reveal the true nature of drugs. In the present clinicopharmacological study, we investigated the effects of histamine H(2) receptor antagonists (H(2)-RAs) on the plasma concentrations of gastrointestinal peptides from the viewpoint of postmarketing development. First we established an enzyme immunoassay for secretin, which is involved in gastrointestinal motility. Then we used this and existing peptide assays to investigate the above-mentioned issues. Ranitidine and nizatidine increased the plasma concentration of motilin. It is believed that the plasma concentration of Ach is elevated by ranitidine and nizatidine, which possesses an anti-AchE activity, and that the increased the plasma concentration of Ach facilitated release of motilin, elevating the plasma concentration of motilin. When compared to the placebo, lafutidine significantly increased the plasma concentration of CGRP (calcitonin gene-related peptide) and substance P. Furthermore, released CGRP stimulated CGRP1 receptors to facilitate secretion of somatostatin. Therefore, lafutidine appears to protect the gastric mucosa and regulate gastrointestinal motility. The same results were obtained with ranitidine and nizatidine. While H(2)-RAs have a common function in suppressing the secretion of gastric acid, they do not exhibit the same effects on factors related to recurrence of peptic ulcer, such as gastrointestinal motility and blood flow in the gastrointestinal mucosa. Hence, measuring the plasma concentration of gastrointestinal peptides can be used to estimate the effects of drugs on gastrointestinal motility. From the viewpoint of postmarketing development, we are in the process of establishing indicators for the proper usage of pharmaceutical drugs. Pharmacists need to closely follow and monitor adverse reactions. In order to further improve monitoring of drug therapy, it will be necessary to assess not only the blood concentrations of drugs, but also biological reactions to the drugs. Since the levels of peptides reflect the clinical efficacy of gastrointestinal drugs, measuring peptide levels appears to be useful for selecting appropriate drugs.

Motilin in human milk and its elevated plasma concentration in lactating women.

BACKGROUND AND AIMS: The aims of this study were to investigate whether: (i) lactating women had an elevated plasma level of motilin; (ii) there was a correlation between the plasma motilin level and the motilin level in breast milk in lactating women; and (iii) there was a difference in motilin levels between the colostrum and mature human milk in a controlled postprandial state. METHODS: Twenty control women and 18 lactating women were enrolled in this study. All samples were drawn in a controlled postprandial state. The concentration of motilin was measured using radioimmunoassay. RESULTS: The plasma motilin level in lactating women was 434 +/- 180 pmol/L on the fifth day after delivery and 450 +/- 204 pmol/L on the 42nd day after delivery (P > 0.05). Both of these values were significantly higher than those in the control women (231 +/- 48 pmol/L, P < 0.05). The motilin level in human milk in the controlled postprandial state was 161 +/- 56 pmol/L on the fifth day and 154 +/- 60 pmol/L on the 42nd day after parturition (P = 0.7). Although there was motilin in the breast milk and an elevated plasma level of motilin in the lactating women, there was no correlation in motilin level between the blood and the breast milk. CONCLUSIONS: Motilin is elevated in the blood of lactating women and human milk contains motilin. These elevated levels of motilin sustain for a period of at least 6 weeks. Further studies are necessary to assess whether motilin is involved in the development of gastrointestinal motility in the early stage of life in infancy.

Neuromodulation of experimental Shigella infection reduces damage to the gut mucosa.

Bacillary dysentery arises when Shigella invades the colonic and rectal mucosae of the human gut and elicits a strong inflammatory response, which may lead to life-threatening complications. Hence, downregulation of the host inflammatory response is an appealing therapeutical alternative. The gastrointestinal tract is densely innervated, and nerve endings are often found in the vicinity of leukocytes. We have assessed the impact of experimental Shigella infection on levels of neuropeptides in the intestinal mucosa of rabbits. Ligated small intestinal loops were created in rabbits, and either live, pathogenic Shigella flexneri, a nonpathogenic mutant of Shigella, or NaCl was injected into the loops. Infection was allowed to proceed for 8 or 16 h, after which the rabbits were sacrificed and intestinal biopsies collected. Tissue destruction, fluid secretion and degree of bacterial invasion were monitored. Intestinal biopsies were homogenized, and levels of the neuropeptides calcitonin gene-related peptide, substance P, peptide YY (PYY), vasoactive intestinal peptide, somatostatin, galanin, motilin and neurotensin were measured by radioimmunoassay. Loops exposed to invasive Shigella had 5.7 times lower levels of PYY (P = 0.0095) than loops exposed to NaCl, after 16 h of infection. The levels of the other neuropeptides tested were unchanged. Inhibition of nicotinic cholinergic neurotransmission partly protected the intestinal mucosa from destruction elicited by invasive Shigella. These findings indicate that a tissue-invasive bacterium such as Shigella, which is strictly localized to the intestinal mucosa, activates intramural nerve reflexes that presumably involve a nicotinic synapse as well as the neuropeptide PYY.

Immunohistochemical study of the distribution of endocrine cells in the gastrointestinal tract of the camel (Camelus bactrianus).

The regional distribution and relative frequency of endocrine cells in the gastrointestinal tract of the camel, Camelus bactrianus, were investigated using immunohistochemical methods. Ten types of immunoreactive (IR) endocrine cells were identified in this study. Among these cell types, only serotonin- and somatostatin-IR cells were detected in almost all regions of the gastrointestinal tract. Most of the cell types showed peak density in the pyloric gland region. The others showed restricted distribution: gastrin, cholecystokinin (CCK), motilin, bovine pancreatic polypeptide (BPP), and (gastric) substance P in the stomach; gastrin, CCK, BPP, gastric inhibitory polypeptide (GIP), glucagon, peptide tyrosine tyrosine (PYY) and substance P in the small intestine; and CCK, motilin, BPP, and PYY in the large intestine. Fundamentally the distribution pattern of endocrine cells in the gastrointestinal tract of the camel is similar to that of cattle. The distribution and frequency of endocrine cells in the glandular sac region are the same as those of the cardiac gland.

Effect of TKS159, a novel 5-hydroxytryptamine4 agonist, on gastric contractile activity in conscious dogs.

A novel 5-hydroxytryptamine (5-HT)4 receptor agonist, TKS159, ¿4-amino-5-chloro-2-methoxy-N-[(2S,4S)-1-ethyl-2- hydroxymethyl-4-pyrrolidinyl] benzamide), has recently been developed as a gastroprokinetic drug. Cisapride is already used clinically to increase gastric contractions. The stimulatory effects of TKS159 and cisapride on gastric contractions were examined using force transducers chronically implanted on the vagally denervated pouch (Heidenhain pouch) and the vagally innervated main stomach in conscious dogs. Contractile activity was analysed by computer and expressed as a motor index. Intravenous administration of TKS159 or cisapride significantly increased the motor index in both the main stomach and the Heidenhain pouch during the fed and fasted states. Pharmacological characterization in the fasted state revealed that the contraction-stimulating activity of TKS159 and cisapride on the stomach was significantly inhibited by atropine, hexamethonium and a 5-HT4 receptor antagonist, SDZ 205-557. Granisetron (a 5-HT3 receptor antagonist) significantly inhibited cisapride-induced, but not TKS159-induced gastric contractions. The plasma motilin concentration was significantly increased after cisapride, but not after TKS159 injection. In conclusion, TKS159 has a contractile-stimulating effect on both the innervated and the denervated stomach. It is likely that a cholinergic pathway and 5-HT4 receptors are involved in producing the contractions, although other mechanisms cannot be excluded. Cisapride has almost the same characteristics, but the present findings suggest the involvement of motilin and 5-HT3 receptors in the effects of cisapride.

Immuno-electron microscopic study of differential localization of motilin and serotonin in the rabbit duodenal epithelium.

A guinea pig antibody against rabbit motilin was generated to study the localization of motilin-containing cells in the rabbit small intestine with special reference to the co-localization of motilin and serotonin. A pre- and post-embedding technique for immuno-electron microscopy was used; duodenal sections were stained with either motilin or serotonin in the pre-embedding DAB-nickel reaction, followed by subsequent staining of ultrathin sections of positive cells with either motilin or serotonin in the post-embedding immunogold reaction. Samples were divided into four groups: 1) pre-motilin, post-motilin, 2) pre-motilin, post-serotonin, 3) pre-serotonin, post-serotonin, and 4) pre-serotonin, post-motilin. Motilin-containing cells in the rabbit duodenum were characterized by round granules (395.3 +/- 66.1 nm in diameter) with medium electron density, located basally or in the perinuclear cytoplasm. In contrast, serotonin-containing cells were characterized by round to pleomorphic secretory granules (344.5 +/- 90.5 nm in diameter with electron dense cores and prominent halos. In motilin-containing cells, massive aggregations of immunogold particles reacted to motilin occurred over secretory granules. A few immunogold particles scattered diffusely over the cytoplasm reacted to serotonin; however, this reaction appeared to be background staining because the density was not changed if the section was treated by preabsorption. In serotonin-containing cells, immunogold particles reacted to serotonin were aggregated over the secretory granules and a large number of gold particles were scattered diffusely at the extragranular cytoplasm; however, very few or no immunogold particles were observed within the cells which reacted to motilin. Results of the present study indicate that motilin and serotonin are not co-localized in the epithelial endocrine cells of the rabbit intestine.

Identification of motilin mRNA in the brain of man and rabbit. Conservation of polymorphism of the motilin gene across species.

The data regarding the identity of motilin-like immunoreactivity in the central nervous system are controversial. The aim of the present study was to clarify whether motilin mRNA is present in the brain of rabbit and man. Total RNA, prepared from several regions of the rabbit brain, was subjected to RT-PCR aimed at amplifying a 294 bp cDNA fragment of the rabbit motilin precursor. The amplified product was subcloned and sequenced. The sequence showed 7 differences compared to the one reported for the duodenal precursor (1). However the duodenal precursor from the rabbit used in the present study revealed identical substitutions. One of these, involving amino acid -11 of the signal peptide, was shown to be due to gene polymorphism, as has also been described at this site in man. By radioimmunoassay the highest concentration of motilin (fmol/mg protein) was detected in the hippocampus (4788 +/- 295), the lowest in the telencephalon (2127 +/- 221). Using a similar approach, but starting from commercial human brain mRNA, the sequence of a comparable cDNA fragment of the human brain motilin precursor was obtained. Its sequence was identical with the one published for the human intestinal precursor (41). Our study demonstrates that motilin mRNA is present in the brain of man and rabbit. Together with our recent findings of central motilin receptors, they suggest a central role for motilin.

[A study on two gut hormones in breast milk].

OBJECTIVE: To determine if motilin and gastrin are present in breast milk and to measure their concentrations in human milk and cow milk. METHODS: The concentration of motilin was measured in 17 samples of human colostrum, 18 samples of human mature milk, 8 samples of cow colostrum and 20 samples of cow mature milk by radioimmunoassay. The concentration of gastrin in human milk was also determined by radioimmunoassay. RESULTS: Motilin concentration in human colostrum was the highest (416.34 +/- 183.95ng/L), being higher than that in human mature milk (272.91 +/- 148.73ng/L, that in cow colostrum (229.51 +/- 63.68ng/L) and that in cow mature milk (35.46 +/- 16.94ng/L). Evidently the difference in motilin concentration was very significant between human milk and cow milk. The gastrin concentration in human colostrum was 17.20 +/- 11.98ng/L, being higher than that in human mature milk (5.62 +/- 2.33ng/L). CONCLUSION: Human milk, especially human colostrum, contains high concentrations of motilin and gastrin. Breast feeding, especially early breast feeding, may promote the maturation of the developing gut in neonates and infants.

Gastrointestinal and pancreatic hormones in the human fetus and mother at 18-21 weeks of gestation.

Several gastrointestinal hormones appear to play an important developmental role in the newborn, particularly in preterm neonates. Although the cells producing these peptides develop towards the end of the first trimester, fetal secretion of these regulatory peptides has not hitherto been demonstrated. Using samples collected by fetoscopy at 19-21 weeks of gestation we have measured concentrations of several gastrointestinal and pancreatic hormones. Maternal venous and amniotic fluid hormone concentrations were measured simultaneously. Concentrations of the pancreatic hormones, insulin, glucagon and pancreatic polypeptide (PP) were similar in fetal and maternal blood. Gastrin and motilin were present in the fetal circulation but at about 30% (p < 0.05) and 60% (p < 0.01) of the maternal levels, respectively. In contrast, enteroglucagon concentrations were more than twofold higher in the fetal circulation compared with maternal levels (p < 0.05). Concentrations of gastric inhibitory polypeptide (GIP) in fetal blood were higher than levels in maternal blood but not significantly. Concentrations of GIP (p < 0.001) were higher in the amniotic fluid than the fetal circulation. Gastrin and glucagon levels were similar in amniotic fluid and fetal blood. In contrast, PP and motilin were present in amniotic fluid, but at lower concentrations than in fetal blood. Enteroglucagon was not detectable in amniotic fluid. In conclusion, several alimentary hormones are secreted in the fetus at midterm. Since these peptides have trophic, secretory and motor effects on the gut, it is likely that these regulatory peptides are involved in the functional development of the fetal intestine.

Immunocytochemical localization of motilin-containing cells in the rabbit gastrointestinal tract.

Motilin-immunopositive cells (Mo cells) are known to be present in the upper small intestine of various species, including man. However, whether Mo cells are present in the rabbit gastrointestinal tract remained to be elucidated. Therefore, this study was designed to investigate the distribution of Mo cells in the rabbit gastrointestinal tract by the avidin-biotin-peroxidase complex method using a new anti-motilin serum (CPV2) raised in chickens. The results of an enzyme-linked immunosorbent assay suggested that this antiserum recognized the C-terminal region of the motilin molecule. Motilin-immunopositive cells were found in the epithelia of the crypts and villi throughout the rabbit gastrointestinal tract from the gastric antrum to the distal colon, but no immunostaining occurred in the gastric body. Morphometric analysis revealed that Mo cells were localized preferentially in the upper small intestine, as reported for other species, and the cell densities (cells/mm2, mean +/- SE) were: gastric antrum (0.41 +/- 0.16), duodenum (8.2 +/- 0.8), jejunum (1.9 +/- 0.5), ileum (0.62 +/- 0.14), cecum (0.19 +/- 0.05), proximal colon (0.13 +/- 0.03), and distal colon (0.39 +/- 0.18). Our results demonstrated conclusively that Mo cells exist in the rabbit gastrointestinal tract and showed for the first time their regional distribution. Furthermore, our new chicken antiserum would appear to be a useful tool for the determination of plasma motilin concentrations by radioimmunoassay and for the immunoneutralization of endogenous motilin in the rabbit.

[Motilin and gastrin in human milk].

The concentrations of motilin and gastrin were determined in the blood and milk of 45 women 3-5 days postpartum, and in the blood of 20 healthy non-pregnant women as control. Plasma motilin concentration (443.05 +/- 140.79 ng/L) and serum gastrin level (301.32 +/- 100.98 ng/L) were significantly higher in postpartum women than those in the control (366.12 +/- 96.23 ng/L and 76.13 +/- 13.11 ng/L, respectively) (P < 0.01). The concentrations of both motilin and gastrin in the milk were approximately one half of those in the blood and they were not present in the boiled milk. The results indicated that both hormones in the human milk may be important for development and maturation of gastro-intestinal function in neonates, especially for immature babies.

Immunohistochemical study of the distribution of endocrine cells in the gastrointestinal tract of the lesser mouse deer (Tragulus javanicus).

The occurrence and distribution of endocrine cells in the gastrointestinal tract of the lesser mouse deer, Tragulus javanicus, were studied immunohistochemically. Fourteen types of endocrine cells immunoreactive for serotonin, somatostatin, enteroglucagon, pancreatic glucagon, bovine pancreatic polypeptide (BPP), gastrin, substance P, motilin, gastric inhibitory polypeptide (GIP), cholecystokinin (CCK), methionine-enkephalin-Arg6-Gly7-Leu8 (MENK-8), secretin, neurotensin, peptide tyrosine tyrosine (PYY) and chromogranin were revealed. Chromogranin-, serotonin-, somatostatin- and enteroglucagon-immunoreactive cells were detected in all regions examined, while pancreatic glucagon-immunoreactive cells, except in the proper gastric gland region, were not found in other regions of the gastrointestinal tract. Few BPP-immunoreactive cells in either the proper gastric gland or pyloric gland regions and abundant gastrin-immunoreactive cells in the pyloric gland region were observed. Restricted distributions of substance P-, GIP-, gastrin-, motilin-, CCK-, MENK-8-, secretin-, neurotensin- and BPP-immunoreactive cells in the small intestine, and BPP-, substance P-, PYY- and motilin-immunoreactive cells in the large intestine were noted. The important findings include the presence of BPP-immunoreactive cells in the abomasum, pancreatic glucagon-immunoreactive cells in the proper gastric gland region, and substance P- and motilin-immunoreactive cells in the large intestine. It is suggested that the distribution pattern of gut endocrine cells in the lesser mouse deer is more similar to that in the pig than in the domestic ruminants so far reported.

Heterogeneity of motilin-immunoreactive cells in the duodenum and pyloric region of several avian species.

Immunohistochemical characterizations of motilin-immunoreactive cells were examined in gastric and duodenal mucosae of nine species of birds from seven orders using five different region-specific motilin antisera. Motilin-immunoreactive cells appeared as open-type cells in the mucosal epithelium and showed varying immunoreactivities to antisera used in all the birds examined except for the cormorant and penguin, which did not show any kinds of immunoreactivity to motilin. Motilin-immunoreactive cells of the emu duodenum were detected by all the motilin-antisera used. The present results suggest that there is a wide range of heterogeneity between motilin molecules among avian species, or perhaps alternatively the existence of a family of motilin-like peptide. Furthermore, the present results should prove useful for a molecular biological study on the evolution of avian motilin.

[Study on the peptides of serum and gastric juice in patients with gastric cancer].

This investigation, conducted on 35 patients with advanced-stage gastric cancer, included 28 men and 7 women with a mean age of 50.1 years; also studied were 33 normal subjects as controls: 26 men and 7 women with a mean age of 45.8 years. Samples of blood and gastric juice were collected at fasting and in gastroscopy respectively. Substance P (SP), beta-endorphin (beta-EP), vasoactive intestinal peptide (VIP), motilin (MTL), gastrin (GT), and leu-enkephalin (LEK) of the sera and gastric juices were measured by radioimmunoassay kits. In the patients, SP and beta-EP of serum and gastric juice, and VIP, MTL and LEK of gastric juice, were higher than in the normal subjects (p < 0.01); gastrin of serum and gastric juice were decreased (p < 0.01). Serum and gastric juice SP, beta-EP levels correlated negatively with the gastrin (r = 0.462-0.519, p < 0.05). These data support the assumption that study of the peptides of serum and gastric juice can show a clinically significant change in gastric cancer patients.

Radioimmunoassay with heterologous antibody (hetero-antibody RIA): utilization of highly cross-reactive antibody present in polyclonal antiserum.

To develop a homologous radioimmunoassay (RIA) for a hormone of a small or rare animal often meets difficulty in collecting a large amount of purified antigen required for antibody production. On the other hand, to employ a heterologous RIA to estimate the hormone often gives poor sensitivity. To overcome this difficulty, a "hetero-antibody" RIA was studied. In a hetero-antibody RIA system, a purified preparation of a hormone is used for radioiodination and standardization and a heterologous antibody to the hormone is used for the first antibody. Canine motilin and rat LH were selected as examples, and anti-porcine motilin and anti-hCG, anti-hCG beta or anti-ovine LH beta was used as the heterologous antibody. The sensitivities of the hetero-antibody RIAs were much higher than those of heterologous RIAs in any case, showing that these hetero-antibody RIA systems were suitable for practical use. To clarify the principle of hetero-antibody RIA, antiserum to porcine motilin was fractionated on an affinity column where canine motilin was immobilized. The fraction bound had greater constants of affinity with both porcine and canine motilins than the rest of the antibody fractions. This fraction also reacted with a synthetic peptide corresponding to the C-terminal sequence common to porcine and canine motilins in a competitive binding test with labeled canine motilin. These results suggest that an antibody population having high affinity and cross-reactivity is present in polyclonal antiserum and indicate that the population can be used in hetero-antibody RIA at an appropriate concentration.