Moderate hypothermia induces a preferential increase in pancreatic islet blood flow in anesthetized rats.
The aim of the study was to characterize the effects of induced moderate hypothermia on splanchnic blood flow, with particular reference to that of the pancreas and the islets of Langerhans. We also investigated how interference with the autonomic nervous system at different levels influenced the blood perfusion during hypothermia. For this purpose, hypothermia (body temperature of 28 degrees C) was induced by external cooling, whereas normothermic (37.5 degrees C) anesthetized Sprague-Dawley rats were used as controls. Some rats were pretreated with either propranolol, yohimbine, atropine, hexamethonium, or a bilateral abdominal vagotomy. Our findings suggest that moderate hypothermia elicits complex, organ-specific circulatory changes, with increased perfusion noted in the pylorus, as well as the whole pancreas and the pancreatic islets. The pancreatic islets maintain their high blood perfusion through mechanisms involving both sympathetic and parasympathetic mediators, whereas the increased pyloric blood flow is mediated through parasympathetic mechanisms. Renal blood flow was decreased, and this can be prevented by ganglionic blockade and is also influenced by beta-adrenoceptors.
Hultström
Michael
M
Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden. michael.hultstrom@med.uib.no
Jansson
Leif
L
Bodin
Birgitta
B
Källskog
Orjan
O
D000311:Adrenal Glands / Q000098:blood supply; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D007036:Hypothermia, Induced; D007328:Insulin / Q000097:blood; D007422:Intestines / Q000098:blood supply; D007515:Islets of Langerhans / Q000098:blood supply*; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D018733:Nicotinic Antagonists / Q000494:pharmacology; D011708:Pylorus / Q000098:blood supply; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000502:physiology; D012079:Renal Circulation / Q000502:physiology; D013152:Splanchnic Circulation / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology; D014628:Vagotomy
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D001786:Blood Glucose; D007328:Insulin; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists