Blood Sugar in Relation to Endocrine Hormones During Hemorrhagic Shock in Dogs

Wiggers' standard method was used to induce hemorrhagic shock in eighteen anesthetized dogs by bleeding to a mean arterial pressure (MAP) of 50 mmHg for 2 hr and then to 30 mmHg for 1 hr, followed by reinfusion of the shed blood. The experimental protocol was designed to determine the sequence of changes in blood sugar during hemorrhagic shock and its relationship to variations in the underlying endocrine hormones, in particular the levels of insulin, catecholamines and cortisol. Venous blood samples were drawn from all experimental animals at specific regular time intervals for sugar and endocrine hormones determination. In early stages of hemorrhagic shock, blood sugar, catecholamines and cortisol were shown to be raised while insulin levels were not influenced by fluctuations in sugar levels. This suggested that, the effect of catecholamine inhibition on the synthesis of insulin is greater than the blood sugar stimulus on the secretion of insulin. Moreover pancreatic islet cells were shown to be intact at terminal stage by Electron microscopy. Corresponding elevated blood levels of sugar, catecholamines and cortisol were found to have a common goal towards increasing plasma osmolality to effect plasma refill. Persistent hypoglycemia in late stages of hemorrhagic shock was shown to be a major sign of failing neuroendocrine compensatory mechanisms against a shock insult. Electron microscopy revealed severe damage of the pituitary gland at the terminal stage.