Engineering of a lipid-polymer nanoarchitectural platform for highly effective combination therapy of doxorubicin and irinotecan.

We developed a highly stable lipid-polymer nanoarchitectural platform for effective combination therapy of doxorubicin and irinotecan in the polyelectrolyte complex nanoparticle core, followed by incorporation of the whole assembly into a lecithin bilayer. It shows great potential for the treatment of a broad range of cancers.

The harmful effects of consumption of repeatedly heated edible oils: a short review.

It has been a regular practice to repeatedly heat the cooking oil and consume it without knowing the harmful effects of such. The procedure to use repeatedly heated cooking oil is aimed to curb the cost of expenses. Heating results is the formation of free reactive oxygen species (ROS) which is responsible for the oxidative stress and damage to various organs in the body. The present review article discusses the harmful events occurring due to consumption of repeated heating of edible oil. A strong message is aimed to generate public awareness of the deleterious effects of consumption of heated edible oil which may help in curbing hypertension and atherosclerosis.

Effects of Polycan, a ß-glucan, on experimental periodontitis and alveolar bone loss in Sprague-Dawley rats.

BACKGROUND AND OBJECTIVE: Polycan is a promising candidate for the treatment of periodontal disease. This study was undertaken to examine whether Polycan, a type of ß-glucan, has a protective effect on ligature-induced experimental periodontitis and related alveolar bone loss in Sprague-Dawley rats. MATERIAL AND METHODS: Polycan was orally administered, daily, for 10 d, at 21.25, 42.5 or 85 mg/kg, beginning 1 d after ligation. Changes in body weight and alveolar bone loss were monitored, and the anti-inflammatory effects of Polycan were determined by measuring the levels of myeloperoxidase (MPO), interleukin-1beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) in gingival tissue. We also evaluated inducible nitric oxide synthase (iNOS) activity and malondialdehyde (MDA) concentrations as a measure of the antioxidant effect. RESULTS: Ligature placement led to a marked decrease in body weight, increased alveolar bone loss and increased concentrations of MPO, IL-1ß, TNF-α and MDA, as well as increased iNOS activity and inflammatory cell infiltration and decreased collagen-fiber content. Histological examination revealed increases in the number and activity of osteoclast cells, decreases in alveolar bone volume and elevated percentages of osteclasts on the alveolar bone surface. Daily oral treatment with 42.5 or 85 mg/kg of Polycan for 10 d led to significant, dose-dependent inhibition of the effect of ligature placement. CONCLUSION: Taken together, these results suggest that 10 d of oral treatment with Polycan effectively inhibits ligature placement-induced periodontitis and related alveolar bone loss via an antioxidant effect.

An immunohistochemical study of the pancreatic endocrine cells of the Korean golden frog, Rana plancyi chosenica.

The regional distribution and quantitative frequency of pancreatic endocrine cells were demonstrated in the Korean golden frog (Rana plancyi chosenica Okada), which is known as a Korean endemic species, for the first time, by immunohistochemical methods using specific mammalian antisera to insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). In the pancreas of the Korean golden frog, all four endocrine cell types were demonstrated. Insulin- and glucagon-positive cells were located in the pancreas as single cells or islet-like clusters with frequencies of 85.90±18.28 and 54.30±8.77/1,000/1,000 cells, respectively. Somatostatin-containing cells were also dispersed in the pancreas as single cells or clusters but in the case of clusters, they are exclusively situated in the marginal regions of insulin- or glucagon-positive cell clusters. Cells stained for somatostatin cell frequency was 15.50±3.10/1000 cells. PP-containing cells were also distributed as single cells or clusters with frequency of 53.40±11.96/1,000 cells. Clusters consisted of PP-positive cells are distributed as a core type and a marginally distributed type. Overall, there were 40.84±3.81% insulin-, 26.02±1.71% glucagon-, 7.63±2.09% somatostatin- and 25.51±3.26% PP-IR cells.

Regional distribution and relative frequency of gastrointestinal endocrine cells in the ddN mice: an immunohistochemical study.

The distributions and frequencies of some endocrine cells in the eight portions of the gastrointestinal (GI) tract - fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum of the ddN mouse, were studied with immunohistochemical method using seven types of antisera against chromogranin (Cg) A serotonin, somatostatin, glucagon, gastrin, cholecystokinin (CCK)-8 and human pancreatic polypeptide (hPP). In the GI tract of ddN mice, CgA, serotonin, somatostatin, glucagon, gastrin, CCK-8 immunoreactive (IR) cells were identified with various frequencies, but hPP-IR cells were not observed in this study. Most of IR cells in the intestinal portion were generally spherical or spindle in shape (open type cell) whereas cells showing round in shape (close type cell) were found in the intestinal gland and stomach regions occasionally. They showed the highest frequency in the pylorus or colon. CgA-IR cells were observed from the pylorus to ileum. Serotonin-IR cells were detected throughout the whole GI tract except for the fundus. Somatostatin-IR cells were demonstrated throughout the whole GI tract except for the cecum and colon. Gastrin and CCK-8-IR cells were restricted to the pylorus and duodenum. In addition, a few glucagon-IR cells were restricted to the fundus and rectum. In conclusion, the general distribution patterns and relative frequency of GI endocrine cells of the ddN mouse was similar to that of other strains of mice. However, some strain and/or species-dependent unique distributions and frequencies of endocrine cells were also observed in the present study.

An immunohistochemical study of the pancreatic endocrine cells of the nude mouse, Balb/c-nu/nu.

The regional distribution and frequency of the pancreatic endocrine cells in the nude mouse, Balb/c-nu/nu were studied by immunohistochemical (peroxidase anti-peroxidase; PAP) methods using specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP). The pancreas of the mouse was divided into two lobes, the splenic and duodenal lobes, and each lobe was subdivided into three regions, the pancreatic islets (central and peripheral regions), the exocrine region and the pancreatic duct region (consisting of duct epithelium and surrounding connective tissue--sub-epithelial connective tissue). In the pancreatic islets, most of insulin-immunoreactive (IR) cells were located in the central region, and glucagon-, somatostatin and hPP-IR cells were located in the peripheral region regardless of the lobe. In the splenic part, glucagon-IR cells were also located in the central regions, and more numerous somatostatin-IR cells were detected in the central regions compared to those of the duodenal part. hPP-IR cells were restricted to the peripheral regions in both lobes but more numerous cells were detected in the duodenal portion as compared to those of the splenic portion. In the exocrine parenchyma of the splenic lobe, only insulin-, glucagon- and somatostatin-IR cells were detected.. Here, the insulin- and glucagon-IR cells formed cell clusters, while somatostatin-IR cells were present as solitary cells. In the exocrine region of the duodenal portion, only insulin-, somatostatin- and hPP-IR cells were observed, with the same distributional pattern as that found in the splenic lobe. However, clusters of cells consisting only of hPP-IR cells were distributed in the pancreas parenchyma as small islets. In the pancreatic duct region, only solitary hPP-IR cells were demonstrated in the sub-epithelial connective tissue regions of the splenic portion. In conclusion, some strain-dependent characteristic distributional patterns of pancreatic endocrine cells, especially of the hPP-IR cells, were found in the nude mouse. In addition, somewhat different distributional patterns were found between the two pancreatic lobes.

The regional distribution and relative frequency of gastrointestinal endocrine cells in the nude mice, Balb/c-nu/nu: an immunohistochemical study.

The distributions and frequencies of some endocrine cells in the eight portions of the gastrointestinal (GI) tract - fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum of the nude mouse, Balb/c-nu/nu were studied with immunohistochemical method using six types of anti-sera against serotonin, gastrin, cholecystokinin (CCK)-8, somatostatin, glucagon and human pancreatic polypeptide (hPP). All of six types of immunoreactive (IR) cells were identified. Most of IR cells in the intestinal portion were generally spherical or spindle in shape (open type cell) while cells showing round in shape (close type cell) were found in the intestinal gland and stomach regions occasionally. Their relative frequencies were varied according to each portion of GI tract. Serotonin-IR cells were detected throughout the whole GI tract and they showed the highest frequency in the pylorus. Gastrin-IR cells were restricted to the pylorus and duodenum with numerous and a few frequencies, respectively. CCK-8-IR cells were also restricted to the pylorus, duodenum and jejunum with numerous, a few and rare frequencies, respectively. Somatostatin-IR cells were demonstrated throughout the whole GI tract except for the colon and rectum, and they showed the highest frequency in the fundus. In addition, glucagon- and hPP-IR cells were restricted to the fundus and rectum, respectively with a few frequencies. In conclusion, the general distribution patterns and relative frequency of GI endocrine cells of the nude mouse, Balb/c-nu/nu was similar to that of other strains of mice. However, some strain and/or species-dependent unique distributions and frequencies of endocrine cells were also observed especially for somatostatin- and hPP-IR cells.

Changes in gastric endocrine cells in Balb/c mice bearing CT-26 carcinoma cells: an immunohistochemical study.

The distribution and density of gastric endocrine cells in Balb/c mice bearing CT-26 carcinoma cells were studied immunohistochemically employing specific antisera against serotonin, somatostatin, glucagon, gastrin, cholecystokinin (CCK)-8 and human pancreatic polypeptide (hPP). The animals were divided into two groups, a non-implanted sham group and a CT-26 carcinoma cell-implanted group. Samples were collected from two regions of the stomach (fundus and pylorus) at 28 days after implantation of the medium or the CT-26 cells (1x10(5) cells/mouse). Five of the 6 types of immunoreactive (IR) cells were identified, with only the hPP IR cells not being detected. The regional distribution of the gastric endocrine cells in the CT-26 implanted group was similar to that of the non-implanted sham group. However, the endocrine cells were significantly decreased in the CT-26-implanted group as compared to those of the non-implanted sham group. Serotonin- and somatostatin-IR cells in the fundus and pylorus , and gastrin- and CCK-8-IR cells in the pylorus of the CT-26 implanted groups were significantly decreased compared to those of the sham group. In addition, glucagon-IR cells were restricted only to the fundus of the sham animals. hPP-IR cells were not detected in either the T-26 implanted- or the non-implanted group. Since endocrine cells are the anatomical units responsible for the production of gut hormones, a change in their density may reflect a change in their capacity to produce such hormones. Implantation of the tumor cell mass induced severe quantitative changes in gastric endocrine cell density, an abnormality which may contribute to the development of gastrointestinal symptoms, such as anorexia and indigestion, frequently encountered in cancer patients.

Distribution and frequency of endocrine cells in the pancreas of the ddY mouse: an immunohistochemical study.

The regional distribution and frequency of pancreatic endocrine cells in ddY mice were studied by an immunohistochemical (peroxidase anti-peroxidase; PAP) method using four types of specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP). In the pancreatic islets, most of insulin-immunoreactive (IR) cells were located in the central portion. Most of glucagon- and somatostatin-IR cells were observed in peripheral regions although a somewhat smaller number of cells were also located in the central regions. HPP-IR cells were randomly distributed throughout the entire islets. In the exocrine pancreas, insulin-, glucagon-, somatostatin- and hPP-IR cells were detected; they occurred mainly among the exocrine parenchyma as solitary cells. Cell clusters consisted of only insulin- or only glucagon-IR cells and were distributed in the pancreas parenchyma as small islets. In addition, insulin- and glucagon-IR cells were also demonstrated in the pancreatic duct regions. Insulin-IR cells were located in the epithelium and sub-epithelial connective tissue regions as solitary cells and/or clusters (3-4 cells), and glucagon-IR cells were mainly located in the epithelium as solitary cells. Overall, there were 63.89+/-5.39% insulin-, 26.52+/-3.55% glucagon-, 7.25+/-2.83% somatostatin- and 1.90+/-0.58% hPP-IR cells. In conclusion, some strain-dependent characteristic distributional patterns of pancreatic endocrine cells were found in the ddY mouse.

Immunohistochemical study on the endocrine cells in gut of the stomachless teleost, Zacco platypus (Cyprinidae).

The regional distribution and relative frequency of neurohormonal peptides-producing cells were demonstrated in the gut of the stomachless teleost, Zacco platypus (Temminck et Schegel), using 10 types of specific antisera raised against mammalian regulatory peptides. The gut of Z. platypus was divided into five portions from proximal to distal (segment I-V). Most of immunoreactive cells in the epithelial lining portion, between epithelial cells, were generally spherical or spindle shape having long cytoplasmic process that was reached via the lumen while cells round in shape were found in the basal portions of epithelial lining occasionally. Serotonin-, somatostatin-, glucagon-, cholecystokinin (CCK)-8 and pancreatic polypeptide (PP)-immunoreactive cells were observed in this study. However, no chromogranin A-, secretin-, vasoactive intestinal peptide (VIP)-, substance P- and bombesin-immunoreactive cells were found. Serotonin-immunoreactive cells were demonstrated throughout the entire gut tract and occurred more frequently than other cells. Somatostatin-immunoreactive cells were restricted to proximal segments of the gut (segment I-III) with rare frequencies, and glucagon-immunoreactive cells were demonstrated in the proximal segments of the gut (segment I, II) with moderate to few occurrences. CCK-8-immunoreactive cells were found throughout the whole intestinal tract except for most proximal segment (segment I) with moderate to few frequencies and PP-immunoreactive cells were demonstrated in the proximal to middle segments, segment I-III, with a few, rare and rare frequencies, respectively.

An immunohistochemical study of gastrointestinal endocrine cells in the BALB/c mouse.

The distributions and frequencies of some endocrine cells in the eight portions of the gastrointestinal tract (GIT) of BALB/c mouse were studied. Endocrine cells were stained using immunohistochemical method with seven types of antisera against bovine chromogranin (BCG), serotonin, gastrin, cholecystokinin (CCK)-8, somatostatin, glucagon and human pancreatic polypeptide (HPP), and the regional distributions and their relative frequencies were observed in the eight portions of the GIT of BALB/c mice. All seven types of immunoreactive (IR) cells were identified. Most of the IR cells in the intestinal portion were generally spherical or spindle in shape (open type cell) while round-shaped cells (closed type cell) were found in the intestinal gland and stomach regions occasionally. Their relative frequencies varied according to each portion of the GIT. BCG-IR cells were observed throughout the whole GIT except for the rectum and they were most predominant in the pylorus. Serotonin-IR cells were detected throughout the whole GIT and they showed the highest frequency in the fundus. Gastrin- and CCK-IR cells were restricted to the pylorus and duodenum with a majority in the pylorus and rare or a few frequencies in the duodenum. Compared with other mammals, somatostatin-IR cells were restricted to the fundus and pylorus with a few frequencies, respectively. In addition, glucagon- and HPP-IR cells were restricted to the fundus and duodenum, respectively, with relative low frequencies. Some species-dependent unique distributions and frequencies of endocrine cells were observed in the GIT of BALB/c mouse compared with other rodents.

The distribution and frequency of endocrine cells in the splenic lobe of grass lizard (Takydromus wolteri). An immunohistochemical study.

The regional distribution and frequency of the pancreatic endocrine cells in the splenic lobe of grass lizard, Takydromus wolteri, were studied by immunohistochemical (PAP) method using six types of specific mammalian antisera against bovine Sp-1/chromogranin (bCG), serotonin, insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP). The pancreas was subdivided into two regions--islet kike and exocrine regions. The frequency of each immunoreactive (IR) endocrine cells was calculated as mean number/total 100 islet cells and as mean number/total 1,000 cells (including exocrine and endocrine cells) using automated image analysis process. In addition, the percentage of each IR cell was also calculated. All of six endocrine cells were demonstrated. They were dispersed in the whole pancreatic parenchyma between exocrine acinar cells, or they were also observed as islet like clusters. In islet-like regions, bCG-, insulin- and glucagon-IR cells were detected as one or two cell layer cords and they were located between this cell-cords with 14.30+/-5.62, 61.50+/-9.76 and 26.50+/-9.31/100 cells frequencies, respectively. However, somatostatin-IR cells were mainly located in the peripheral parts not in cell-cords with 12.40+/-4.86/100 cells, and no serotonin- and hPP-IR cells were demonstrated. In exocrine regions, all of bCG-, serotonin-, insulin-, glucagon-, somatostatin- and hPP-IR cells were detected and they occurred mainly among the exocrine parenchyma as solitary cells with 10.30+/-2.54, 0.80+/-0.63, 15.50+/-5.30, 5.80+/-2.66, 3.10+/-1.29 and 11.00+/-3.33/1000 cells frequencies, respectively. In addition, serotonin-IR cells were mainly located between epithelia and connective tissue of pancreatic duct. Overall, there were 0.58+/-0.49% serotonin-, 56.44+/-9.35% insulin-, 23.73+/-8.22% glucagon-, 11.28+/-3.03% somatostatin- and 7.97+/-2.02% hPP-IR cells.

An immunohistochemical study of endocrine cells in the pancreas of the Red-bellied frog (Bombina orientalis).

The regional distribution and frequency of pancreatic endocrine cells in the red-bellied frog, Bombina orientalis, were studied by the immunohistochemical peroxidase anti-peroxidase (PAP) method using five types of specific mammalian antisera to insulin, glucagon, somatostatin, bovine pancreatic polypeptide (PP) and secretin. The frequency was calculated as the mean number of each endocrine cell type/1,000 total cells (including exocrine and endocrine cells) using an automated image analysis process. The percentage of each immunoreactive (IR) cell species to the total IR cell population was also calculated. In the pancreas of the red-bellied frog, all five endocrine cell types were demonstrated. Insulin IR cells were located in the pancreas as single cells or islet-like clusters. The latter were localized in central regions. The insulin-IR cells showed a frequency of 65.40 plus/minus 14.56/1,000 cells. Glucagon IR cells were also detected as single cells or as clusters but in the case of clusters, two distributional patterns were detected - a central core type and a marginally distributed type. They showed an abundance of 32.70 plus/minus 7.32/1,000 cells. Somatostatin-IR cells were dispersed throughout the pancreatic parenchyma as single cells, three to four cells, or clusters. The clusters were located in the marginal regions. The somatostatin-IR cell frequency was 19.40 plus/minus 6.52/1000 cells. PP-IR cells were randomly distributed throughout the pancreatic parenchyma as single cells with a frequency of 14.70 plus/minus 4.92/1,000 cells. Secretin-IR cells were demonstrated as clusters or as single cells, and as clusters they occupied the central regions. They showed a frequency of 39.60 plus/minus 10.36/1,000 cells. This is the first report of the presence of secretin-IR cells in amphibian pancreatic endocrine cells. Overall, there were 37.20 plus/minus 6.84% insulin-, 21.90 plus/minus 5.55% glucagon-, 11.60 plus/minus 4.33% somatostatin-, 8.60 plus/minus 2.72% PP- and 23.40 plus/minus 4.45% secretin-IR cells.

An immunohistochemical study of the gastrointestinal endocrine cells in the C57BL/6 mice.

The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the eight portions (fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum) of the gastrointestinal tract of C57BL/6 mouse was studied with immunohistochemical method using seven types of specific anti-sera against chromogranin A (CGA), serotonin, somatostatin, human pancreatic polypeptide (HPP), glucagon, gastrin and cholecystokinin (CCK)-8. In this study, all these seven types of immunoreactive (IR) cells were identified. Most of these IR cells in the intestinal portion were generally spherical or spindle in shape (open-type cell) while cells showing round in shape (closed-type cell) were found in the intestinal gland and stomach regions occasionally. Their relative frequencies were varied according to each portion of gastrointestinal tract. CGA-IR cells were demonstrated throughout the whole gastrointestinal tract and they showed most predominant in the pylorus and duodenum. Serotonin-IR cells were detected throughout whole gastrointestinal tract and they showed highest frequency in the stomach and colon. Somatostatin-IR cells were demonstrated throughout whole gastrointestinal tract except for large intestine and showed highest frequency in the fundus. HPP-IR cells were found in the fundus with rare frequency. Peculiarly, glucagon-IR cells were restricted to the fundus, ileum and colon with a few frequencies. Gastrin-IR cells were restricted to the pylorus with numerous frequency and CCK-8-IR cells were observed in the pylorus, duodenum and jejunum with numerous and/or a few frequencies, respectively. In conclusion, some peculiar distributional patterns of gastrointestinal endocrine cells were found in C57BL/6 mouse.

An immunohistochemical study of pancreatic endocrine cells in SKH-1 hairless mice.

The regional distribution and frequency of the pancreatic endocrine cells in the SKH-1 hairless mouse were studied by an immunohistochemical (peroxidase anti-peroxidase; PAP) method using four types of specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). The pancreas of mice were divided into three portions; pancreatic islets, exocrine and pancreatic ducts. The pancreatic islets were further subdivided into three regions (central, mantle and peripheral region) according to their located types of immunoreactive cells. In the pancreatic islet portions, insulin-immunoreactive cells were located in the central and mantle regions with 84.60 +/- 7.65 and 33.00 +/- 12.45/100 cells frequencies, respectively, but most of somatostatin-, glucagon- and PP-immunoreactive cells were detected in the mantle and peripheral regions. In the mantle region, somatostatin-, glucagon- and PP-immunoreactive cells were demonstrated with 28.70 +/- 9.91, 52.00 +/- 14.05 and 2.60 +/- 1.51/100 cells frequencies, respectively, and showed 6.20 +/- 2.86, 15.30 +/- 5.31 and 21.50 +/- 10.28/100 cells frequencies, respectively in peripheral regions. However, glucagon-immunoreactive cells were also demonstrated in the central regions with 4.00 +/- 2.83/100 cells frequency. In the exocrine portions, insulin-, glucagon-, somatostatin- and PP-immunoreactive cells were demonstrated in the SKH-1 mouse with 0.90 +/- 0.74, 0.80 +/- 0.79,4.90 +/- 3.54 and 2.70 +/- 1.34/100 cells frequencies, respectively. In the pancreatic duct portions, insulin-, glucagon- and somatostatin-immunoreactive cells were demonstrated in the subepithelial connective tissues and showed islet-like appearances with 30.30 +/- 14.67, 2.70 +/- 3.13 and 5.90 +/- 4.23/100 cells frequencies, respectively. However, no PP-immunoreactive cells were demonstrated in these regions. In conclusion, some peculiar distributional patterns of pancreatic endocrine cells were found in the SKH-1 hairless mouse.

The regional distribution and relative frequency of gastrointestinal endocrine cells in SHK-1 hairless mice: an immunohistochemical study.

The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the eight portions (fundus, pylorus, duodenum, jejunum, ileum, caecum, colon and rectum) of the gastrointestinal tract of SKH-1 hairless mice were investigated using immunohistochemical methods and seven types of specific antisera against somatostatin, serotonin, glucagon, cholecystokinin (CCK)-8, secretin, pancreatic polypeptide (PP) and gastrin. In this study, somatostatin-, serotonin-, glucagon-, CCK-8-, secretin- and gastrin-immunoreactive (IR) cells were identified. Most of these IR cells in the intestinal portion were generally spherical or spindle-shaped (open-type cell) while cells that were round in shape (close-type cell) were occasionally found in the stomach regions. Their relative frequencies were varied according to each portion of gastrointestinal tract. Somatostatin-IR cells were found throughout the gastrointestinal tract except for the large intestine. Serotonin-IR cells were detected throughout the whole gastrointestinal tract and were the most predominant endocrine cell types in this species of mouse. Glucagon-IR cells were restricted to the fundus, occurring rarely. CCK-8-IR cells were observed in the pylorus, duodenum and jejunum with frequencies that were numerous, moderate and few, respectively. Peculiarly, secretin-IR cells were demonstrated in the whole intestinal tract with either few or rare frequencies. Gastrin-IR cells were restricted to the pylorus and were numerous. However, no PP-IR cells were found in this study. In conclusion, some peculiar distributional patterns of gastrointestinal endocrine cells were found in SKH-1 hairless mouse.

An immunohistochemical study on the endocrine cells in the alimentary tract of the red-eared slider (Trachemys scripta elegans).

The regional distribution and relative frequency of endocrine cells in the alimentary tract of the red-eared slider, Trachemys scripta elegans, were investigated by immunohistochemical methods using 10 antisera. Most of the immunoreactive cells in the intestine were spherical or spindle-like in shape (open-type cells), while round cells (closed-type cells) were occasionally found in the stomach. These immunoreactive cells were located in the basal portion of the intestine, including the oesophagus, and in the gastric glands of the stomach. Cg A-immunoreactive cells were restricted to the pylorus and duodenum and were few in number. Serotonin-immunoreactive cells, which were most commonly found in the pylorus, were found in the epithelia throughout the alimentary tract at various frequencies. Gastrin-immunoreactive cells were found in the pylorus, duodenum and jejunum at moderate, low and very low frequencies, respectively. Somatostatin-immunoreactive cells were found throughout the alimentary tract except for the rectum, at various frequencies. Glucagon-immunoreactive cells were detected in the fundus, pylorus, jejunum and ileum at low or very low frequencies. CCK-8-immunoreactive cells were found in the pylorus, fundus and duodenum at very low, low and moderate frequencies, respectively. Bombesin-immunoreactive cells were restricted to the fundus and pylorus at low frequencies. No secretin-, BPP- or VIP-immunoreactive cells were found in this study.

Comparative study of endocrine cells in the principal pancreatic islets of two teleosts, Silurus asotus (Siluridae) and Siniperca scherzeri (Centropomidae).

The regional distribution and relative frequency of some endocrine cells in the principal pancreatic islets of two teleosts, Silurus asotus Linne (Siluridae) and Siniperca scherzeri Steindachner (Centropomidae), which have similar feeding habits, were observed using specific antisera against insulin, glucagon, somatostatin and bovine pancreatic polypeptide (bovine PP) using the peroxidase antiperoxidase (PAP) method. Spherical to spindle shaped cells were demonstrated in the principal pancreatic islets in both species of teleost fishes. However, they were not detected in the exocrine portions nor the pancreatic ducts. Insulin-immunoreactive cells were located in the central regions of the principal pancreatic islets at high frequency in both species. Glucagonimmunoreactive cells were restricted to the peripheral regions of the principal pancreatic islets in both species. They formed a mantle zone in the peripheral regions of Silurus asotus with moderate frequency, and occupied a narrower mantle zone in Siniperca scherzeri with moderate frequency. In addition, glucagonimmunoreactive cell cores were also found in the peripheral zone of some principal pancreatic islets of Siniperca scherzeri. Somatostatin-immunoreactive cells were dispersed in the central zone of the principal pancreatic islets of Silurus asotus with moderate frequency, but were located in the peripheral regions with low frequency in Siniperca scherzeri. Bovine PPimmunoreactive cells were found in the peripheral region and the mantle zone of the principal pancreatic islets with low and rare frequency, respectively in both species. In conclusion, the regional distribution and relative frequency of endocrine cells in the principal pancreatic islets of Silurus asotus showed general patterns similar to those of other teleostean fishes. But, some speciesdependent distributional patterns and/or relative frequencies, particularly in glucagon-, somatostatin- and bovine PP-immunoreactive cells, were detected in the principal pancreatic islets of Siniperca scherzeri.

An immunohistochemical study on the pancreatic islets cells of the Mongolian gerbils, Meriones unguiculatus.

In order to study the regional distribution and relative frequency of the immunoreactive endocrine cells in the pancreatic islets of the Mongolian gerbil, pancreatic sections of Meriones unguiculatus were immunostained using an immunohistochemical (PAP) method with four types of specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). The pancreatic islets were subdivided into three portions (central region, mantle zone and peripheral region) according to their composition of immunoreactive cells. Spherical to spindle shaped insulin, glucagon, somatostatin and PP-immunoreactive cells were observed in this study. Insulin-immunoreactive cells were present in the central regions with high frequency, and a few of these cells were also demonstrated in the mantle zones. Glucagon-immunoreactive cells were mainly restricted to the mantle zones. However, rare examples were found in the peripheral regions. As for the glucagon-immunoreactive cells, somatostatin-immunoreactive cells were detected in the mantle zones and peripheral regions with moderate and rare frequencies, respectively. PP-immunoreactive cells were found in the mantle zones and peripheral regions with rare and moderate frequencies, respectively. In the mantle and the peripheral regions, cytoplasmic process of glucagon-, somatostatin- and PP-immunoreactive cells were intermingled. In conclusion, the regional distribution of endocrine cells in the pancreatic islets of Mongolian gerbil was found to be similar to that of other mammals, especially other rodents, except for the topographical different distribution of somatostatin which differs that of other rodents.

An immunohistochemical study of endocrine cells in the alimentary tract of the red-bellied frog, Bombina orientalis.

The regional distribution and relative frequency of endocrine cells was studied immunohistochemically (PAP method) in the alimentary tract of the red-bellied frog, Bombina orientalis, using antisera against serotonin, somatostatin, chromogranin (CG), cholecystokinin (CCK)-8, bombesin, secretin, glucagon and pancreatic polypeptide (PP). Eight kinds of endocrine cells were identified in this study. These immunoreactive cells were located in the gastric glands of the stomach regions and in the intestinal or esophageal epithelium with variable frequencies. They were spherical or spindle-shaped. Serotonin- and somatostatin-immunoreactive cells were demonstrated in the whole alimentary tract including esophagus. CG-immunoreactive cells were restricted to the stomach. CCK-8-immunoreactive cells were observed from the antrum to the ileum. Bombesin-immunoreactive cells were restricted to the stomach. Secretin-immunoreactive cells were demonstrated in the pylorus, duodenum and ileum. Glucagon-immunoreactive cells were found in the antrum and duodenum. PP-immunoreactive cells were detected from the antrum to the rectum. In conclusion, throughout the alimentary tract of the red-bellied frog, the different regional distribution and relative frequency of endocrine cells were demonstrated. The regional distributions and relative frequencies of the endocrine cells in the alimentary tract of the red-bellied frog were resembled to those of the other anuran species except for esophagus.