Effect of pancreatic polypeptide on DNA-synthesis in the pancreas

Summary Bovine pancreatic polypeptide increases DNA-synthesis in the rat pancreas; no effect is observed in stomach (oxyntic area), duodenum or liver. BPP neither augments or inhibits the trophic action of cholecystokinin.Acknowledgment. Pure pancreatic polypeptide was donated by Dr. R. E. Chance (Lilly Research Laboratories, Eli Lilly and Co., Indianapolis, Ind, USA). G. R. Greenberg is supported by a Fellowship of the Medical Research Council of Canada.     

Co-localization of glucagon and pancreatic polypeptide in testudine pancreas

Summary Immunocytochemistry was carried out on sections of pancreas from the gopher tortoise,Gopherus polyphemus. Combined immunofluorescent and peroxidase-anti-peroxidase techniques showed unequivocally that some of the cells were immunoreactive for both glucagon and pancreatic polypeptide (PP). Antibodies directed against avian PP, bovine PP, and human PP all have a positive reaction. Co-localization of glucagon and PP in the pancreas of the gopher tortoise indicates that the occurrence of these hormones in the same cells is widespread in higher vertebrates.Acknowledgments. This work was supported in part by grants from the University of Cape Town, the M. Crossley bequest, the N. Atkinson bequest, and Herman and Caporn bequests. The generous gifts of antisera by Dr Chance and the late Dr Kimmel, and the gift of hormones by the Lilly Research Laboratories are gratefully acknowledged. The excellent technical assistance of J. Thompson and J. B. De Haan is also gratefully acknowledged. Please send all correspondence to the USA address.     

Glucagon and pancreatic polypeptide immunoreactivities co-exist in a population of rat islet cells

Summary In mammalian pancreas, glucagon and pancreatic polypeptide have been shown to be present in distinct cell types. The present communication reports that, in rat pancreas, in addition to glucagon and pancreatic polypeptide cell populations, there is a small population of cells which contain both glucagon and pancreatic polypeptide immunoreactivities.     

Glucagon and pancreatic polypeptide immunoreactivities co-exist in a population of rat islet cells

In mammalian pancreas, glucagon and pancreatic polypeptide have been shown to be present in distinct cell types. The present communication reports that, in rat pancreas, in addition to glucagon and pancreatic polypeptide cell populations, there is a small population of cells which contain both glucagon and pancreatic polypeptide immunoreactivities.     

Presence of "pancreatic polypeptide" cells, and gastrin immunoreactivity in immuno-induced exocrine pancreas carcinoma]

1) In electively immuno-induced carcinomas of the exocrine pancrease in Mice, where A (glucagon) and B (insulin) endocrine cells persist, cells with a pancreatic polypeptide immunoreactivity are also detected, even in late evolution stages. These cells, like D cells, containing somatostatin, are localized only in the pancreatic remains surrounding the anaplasic carcinomatous tissue: islets, adenomatous parenchyma, and ductular epithelium. Ultrastructure of these cells shows their active elaboration of numerous chracteristic secretion granules. (2) Immunocytoenzymatic detection of gastrin is negative in the exocrine and endocrine pancreatic tissues. However one of the anti-gastrin sera used gives a positive reaction, in some carinomatous cells only. Does this immunoreactivity characterize a polypeptide specific to the pancreatic carcinomatous cell?     

Localization of bovine pancreatic polypeptide (BPP)-like immunoreactivity in rat pancreatic monolayer culture

Summary Antiserum to bovine pancreatic polypeptide (BPP) has been used for immunofluorescent staining in the light microscope. With this technique it is possible to detect the presence of specific cells in monolayer culture from neonatal rat pancreas which contain BPP or a closely related peptide.This work was supported by a grant (No. 3.553.75) from the Fonds National Suisse de la Recherche Scientifique. We are very grateful to Dr.R. E. Chance, Eli Lilly, for his generous gift of BPP and anti-BPP serum. We are also very obliged to Dr.R. H. Unger for providing glucagon, to Dr.J. Rivier and Dr.R. Guillemin for somatostatin, to Dr.N. Yanaihara for secretin, to Dr.W. Gepts for gastrin and to Dr.A. J. Moody for GLI.     

Localization of bovine pancreatic polypeptide (BPP)-like immunoreactivity in rat pancreatic monolayer culture.

Antiserum to bovine pancreatic polypeptide (BPP) has been used for immunofluorescent staining in the light microscope. With this technique it is possible to detect the presence of specific cells in monolayer culture from neonatal rat pancreas which contain BPP or a closely related peptide.     

Regional distribution of thiamin pyrophosphokinase in rat brain

The highest specific activity of thiamin pyrophosphokinase was found in the cerebellum, and lower activity in cerebral cortex and midbrain. The regional difference in the enzyme activity was similar to that in thiamin content and the influx rate in rat brain, suggesting that the enzyme is involved in the thiamin transport.     

Regional distribution of thiamin pyrophosphokinase in rat brain

Summary The highest specific activity of thiamin pyrophosphokinase was found in the cerebellum, and lower activity in cerebral cortex and midbrain. The regional difference in the enzyme activity was similar to that in thiamin content and the influx rate in rat brain, suggesting that the enzyme is involved in the thiamin transport.     

Occurrence, distribution and nature of neuropeptide Y in the rat pancreas

Significant quantities of a newly discovered peptide, neuropeptide Y, were found in the rat pancreas, where they were localized to nerves in the exocrine parenchyma and around arterial and ductal structures. Although unaffected by surgical parasympathectomy, the periarterial and periductal nerves were abolished by chemical sympathectomy, suggesting that NPY is partially costored with sympathetic transmitters in nerve fibers.     

Occurrence,distribution and nature of neuropeptide Y in the rat pancreas

Summary Significant quantities of a newly discovered peptide, neuropeptide Y, were found in the rat pancreas, where they were localized to nerves in the exocrine parenchyma and around arterial and ductal structures. Although unaffected by surgical parasympathectomy, the periarterial and periductal nerves were abolished by chemical sympathectomy, suggesting that NPY is partially costored with sympathetic transmitters in nerve fibers.     

Immunofluorescent demonstration of pancreatic polypeptide (PP) in pancreas and digestive tube of bony and cartilaginous fish]

When antisera specific against bovine PP (BPP) were used, immunoreactive parenchymal cells were observed in the endocrine pancreas and in the gastro-intestinal tract of the teleost bony fish Cottus scorpius, as well as in the pancreas of the elasmobranchian cartilaginous fish Squalus acanthias. Of the two principal islets of Cottus, PP-cells were located selectively to that in the pyloric region.     

DPH-induced macrocytosis in the 14-day rat foetus

Phenytoin injected in the pregnant rat induces in the 14-day-old foetus macrocytosis of the primitive red blood cells which is sometimes linked with limb haemorrhages. The action of the drug is possibly the result of a blood circulation disturbance.     

DPH-induced macrocytosis in the 14-day rat foetus

Summary Phenytoin injected in the pregnant rat induces in the 14-day-old foetus macrocytosis of the primitive red blood cells which is sometimes linked with limb haemorrhages. The action of the drug is possibly the result of a blood circulation disturbance.     

Regional distribution of lactate dehydrogenase isoenzymes in adult rat brain.

The highest lactate dehydrogenase (LDH) activity was found in thalamus, statistically significantly less in cerebral and cerebellar cortex and the lowest in pons. LDH1 and LDH4+5 represented 58% and 23% of the total activity in cerebral cortex, 54% and 20% in thalamus, 42% and 4% in cerebellar cortex and 55% and 7% in pons, respectively.     

Ontogenic development of peptide hormones in the mammalian fetal pancreas

Summary The ontogeny of insulin, glucagon, PP and somatostatin in the mammalian fetal pancreas has been examined in recent years largely by immunocytochemistry and in some instances by radioimmunoassay. Complete ontogenic data are available only for the rat, human pig and sheep. Figure 3 compares the time of appearance of the endocrine cell-types within the fetal pancreas when the periods of gestation of the four species are converted to a uniform scale. The striking ontogenic difference in the rat probably reflects the immaturity of the rodent fetus at birth compared with the human, pig and sheep. In the fetal pancreas, differences in cell number of glucagon and PP cells in the dorsal and ventral lobes become apparent from an early gestational period. Factors responsible for the functional and structural maturation of the fetal pancreatic endocrine cells and the processes involved in pancreatic organogenesis are poorly understood. Studies in these areas would have clinical implications since it may be possible in the future to employ agents for selective replication of fetal -cells for transplantation in patients with Type I diabetes, bearing in mind that such cells must have the capacity to respond to normal stimuli and repressors when transplanted. The presence of the other islet cell-types may be obligatory for these appropriate responses. This would require a more complete knowledge of those factors which produce the normal selectivity of the four hormonal cell-types.     

Ontogenic development of peptide hormones in the mammalian fetal pancreas

The ontogeny of insulin, glucagon, PP and somatostatin in the mammalian fetal pancreas has been examined in recent years largely by immunocytochemistry and in some instances by radioimmunoassay. Complete ontogenic data are available only for the rat, human, pig and sheep. Figure 3 compares the time of appearance of the endocrine cell-types within the fetal pancreas when the periods of gestation of the four species are converted to a uniform scale. The striking ontogenic difference in the rat probably reflects the immaturity of the rodent fetus at birth compared with the human, pig and sheep. In the fetal pancreas, differences in cell number of glucagon and PP cells in the dorsal and ventral lobes become apparent from an early gestational period. Factors responsible for the functional and structural maturation of the fetal pancreatic endocrine cells and the processes involved in pancreatic organogenesis are poorly understood. Studies in these areas would have clinical implications since it may be possible in the future to employ agents for selective replication of fetal beta-cells for transplantation in patients with Type I diabetes, bearing in mind that such cells must have the capacity to respond to normal stimuli and repressors when transplanted. The presence of the other islet cell-types may be obligatory for these appropriate responses. This would require a more complete knowledge of those factors which produce the normal selectivity of the four hormonal cell-types.