Describe the physiological consequences that follow an intravenous bolus of 50mls of 50% glucose.
It was expected answers would include a comment this would transiently increase the blood glucose and result in the stimulation of insulin production. Some detail was then required on the mechanism by which insulin production is increased and time frames over which this occurred, as well as mechanism by which glucose passes through to the urine. Other important points expected were the fate of glucose, once taken up by the cells, the inhibitory effects (and mechanisms) of insulin (ie inhibits glycogenolysis, triglyceride and protein breakdown, etc). A description of the physiological consequences of increased insulin production was required. This question has been asked before, in it’s current form. The pass rate on this occasion was higher. Candidates who did poorly did so due to a lack of detail and understanding of the topic.
Judging from the examiner comments, something like the following was expected:
Gerich, John E. "Physiology of glucose homeostasis." Diabetes, Obesity and Metabolism 2.6 (2000): 345-350.
Herman, Mark A., and Barbara B. Kahn. "Glucose transport and sensing in the maintenance of glucose homeostasis and metabolic harmony." The Journal of clinical investigation 116.7 (2006): 1767-1775.
Regittnig, Werner, et al. "Assessment of transcapillary glucose exchange in human skeletal muscle and adipose tissue." American Journal of Physiology-Endocrinology and Metabolism 285.2 (2003): E241-E251.
Balentine, Jerry R., et al. "Effect of 50 milliliters of 50% dextrose in water administration on the blood sugar of euglycemic volunteers." Academic emergency medicine 5.7 (1998): 691-694.