Previous morphological studies of mammalian pancreatic islets have been performed mainly in domestic and laboratory animals. Therefore, the present immunohistochemical investigation was conducted in a wild species, the European bison, using antibodies against glucagon-like peptide-1 (GLP1), glucagon, insulin and somatostatin. Morphological analyses revealed that the mean area of the endocrine pancreas constituted 2.1±0.1% of the whole area of the pancreas, while the mean area of a single pancreatic islet was 13301.5±686.5 µm2. Glucagon-immunoreac- tive cells accounted for 22.4±1.1% and occupied 19.4±0.4% of the average islet area. As many as 14.3±1.4% of pancreatic islet cells were shown to express GLP1, which constituted 12.6±0.8% of the mean area of the islet. Insulin expression was confirmed in 67.6±0.7% of pancreatic islet cells, which represented 62.3±4.9% of the mean total area of the pancreatic islet. As many as 8.5±1.3% of cells stained for somatostatin. The somatostatin-immunoreactive cell area was 4.9±0.3% of the mean pancreatic islet area. In summary, we have determined in detail for the first time the morphometry and islet composition of the European bison pancreas. The distri- bution patterns of immunoreactivities to the substances studied in the European bison show many similarities to those described in other ruminant species.

Intensive hypoglycemic treatment is the strongest preventive strategy against the development of microvascular complications of type 2 diabetes (T2DM), including diabetic nephropathy. However, some antidiabetic drugs, i.e. sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and glucagon-like peptide-1 receptor agonists (GLP1-RA) have an additional renoprotective effect beyond glucose control by itself. Similar, both SGLT-2i and GLP1-RA have been demonstrated to decrease the risk of adverse cardiovascular (CV) events in CV outcome trials. Nevertheless, there are relevant differences in CV and renal effects of SGLT-2i and GLP1-RA. First, SGLT2i reduced the incidence and progression of albuminuria and prevented loss of kidney function, while predominant renal benefits of GLP1-RA were driven by albuminuria outcomes. Second, the risk of heart failure (HF) hospitalizations decreased on SGLT2i but not on GLP1-RA, which gives priority to SGLT2i in T2DM and HF, especially with depressed EF. Third, either GLP1-RA (reducing predominantly atherosclerosis-dependent events) or SGLT-2i, should be used in T2DM and established atherosclerotic CV disease (ASCVD) or other indicators of high CV risk. In this review, we have briefly compared clinical practice guidelines of the American Diabetes Association (2020 and 2021 versions), Polish Diabetes Association (2020) and the European Society of Cardiology/European Association for the Study of Diabetes (2019), with a focus on the choice between SGLT-2i and GLP1-RA in patients with diabetic kidney disease.