TASAKA, Y., MATSUMOTO, H., INOUE, Y. and HIRATA, Y. Contents and Secretion of Glucagon and Insulin in Rat Pancreatic Islets from the Viewpoint of Their Localization in Pancreas. Tohoku J. Exp. Med., 1989, 159 (2), 123-130- Regional difference in secretion of glucagon and insulin from the rat pancreatic islets and their contents in pancreatic tissue and islets were studied. The glucagon content in the normal rat pancreas was the highest at the splenic part followed in order by the gastric, choledochal and duodenal parts. The effect of alloxan on the glucagon content was stronger in the dorsal lobe (combined gastric and splenic parts) than in the ventral lobe (combined duodenal and choledochal parts), and more increase of glucagon was found. The size of pancreatic islets was similar between the dorsal and the ventral lobe. The glucagon content in the islets was significantly higher in the dorsal lobe than in the ventral lobe, but the insulin content in the islets was similar in both lobes. The release of insulin from cultured pancreatic islets from the dorsal lobe was similar to that from the ventral lobe, but the release of glucagon was significantly high from the cultured islets of the former in the presence of glucose or arginine compared with that from the latter. Also in isolated pancreatic islets the release of glucagon was significantly more marked in the islets from the dorsal lobe by arginine administration. These findings show that the islets from the dorsal lobe secrete and contain more glucagon than those from the ventral lobe in contrast to there being a similar amount of release of insulin between them.
Changes in canine plasma glucose, immunoreactive glucagon (IRG), pancreatic polypeptide (PP) and insulin (IRI) were studied during the acute development of diabetes mellitus after iv alloxan injection. 100 mg or 75 mg/kg body weight of alloxan was injected iv and blood was taken successively till one or two days later. Plasma glucose showed four phases: first immediate and moderate decrease appeared 30 min after injection, second initial hyperglycemic phase, third hypoglycemic and fourth diabetic ones. Plasma IRI had already increased to 182 +/- 60 microU/ml 10 min after injection and again began to increase after about 6 h, peaking to 134 +/- 49 microU/ml at 18 h. Plasma IRG began increasing gradually soon after alloxan injection. The initial value was 196 +/- 26 pg/ml and it increased to 534 +/- 144 pg/ml at 4 h during the initial hyperglycemic phase, then reached a higher level through the hypoglycemic and diabetic phases. The change in plasma PP was similar to that in IRG. The initial value was 256 +/- 95 pg/ml at 12 h after injection, peaking to 840 +/- 100 pg/ml in the hypoglycemic phase. Similar blunted values were obtained following 75 mg/kg alloxan injection. Thus not only plasma IRI but also plasma IRG and PP varied greatly during the acute development of alloxan diabetes and some contribution of IRG to the initial hyperglycemic phase was suggested.
The stomach contents (food and ingested plastics) of Laysan Albatross Phoebastria immutabilis and Black-footed Albatross P. nigripes were examined by necropsy analysis of birds caught as bycatch in the pelagic longline fisheries in the Western North Pacific. The contents were classified separately for the proventriculus and gizzard. Undigested fish and cephalopods were found in the proventriculus, while hard objects such as cephalopod beaks, plastics, and pebbles were found in the gizzard. This indicates that the retention time of soft tissues in fish or cephalopods differs from that for hard objects. The main prey of both albatrosses consisted of mesopelagic cephalopods such as Cranchiidae, Gonatidae, Histioteuthidae, and Onychoteuthidae species. Laysan Albatrosses also foraged on small teleosts (Japanese Anchovy Engraulis japonicus and some Myctophidae fishes) as major prey items. The estimated dorsal mantle length of cephalopods preyed upon by the albatrosses was below 200 mm, which was smaller than the mature sizes of those cephalopods and the size class mainly preyed upon by cetaceans. This implies that the albatrosses may forage on immature cephalopods floating in the surface layer. Ingested plastics were found in 71.8% of Laysan and 31.8% of Black-footed Albatrosses and plastic fragments were the most abundant.
Background Studies have indicated that the impact of a traumatic experience can be negative and can provide the opportunity to experience psychological growth, known as posttraumatic growth (PTG). Objective To evaluate the role of cognitive processing in PTG among parents of childhood cancer survivors (CCSs) based on the PTG theoretical model. We compared the model between parents of SCC and parents of children with chronic disease (CCDs) to determine how the role of cognitive processing in PTG is different depending on the children’s illness. Methods Final sample consisted of 78 parents of CCSs and 44 parents of CCDs. The survey included standardized measurements assessing reexamination of core beliefs, intrusive and deliberate rumination, posttraumatic stress symptoms, and PTG. The hypothetical relationships among the variables were tested by covariance structure analysis. Results Posttraumatic growth among parents of CCSs had significantly strong association with reexamination of core beliefs, but not with deliberate rumination. Reexamination of core beliefs was significantly more likely to foster PTG among parents of CCSs, whereas deliberate rumination was significantly more likely to be associated with PTG among parents of CCDs. Conclusions For parents of CCSs, reexamination of core beliefs had a greater impact on PTG than deliberate rumination. Our results suggest that support should focus on the process of reexamining core beliefs in facilitating PTG among parents of CCSs. Implications for Practice Nurses should provide parents of CCSs with reassurance regarding their experiences of the reexamination of core beliefs, which will likely lead to PTG.
