Splanchnic haemodynamic changes during acute hypoglycaemia in man

Abstract

1. Splanchnic haemodynamic changes were studied in seven healthy subjects during hypoglycaemia induced by the intravenous infusion of insulin. Superior mesenteric artery blood flow and cardiac output were examined non-invasively by a Doppler ultrasound technique. 2. Blood glucose concentration fell from 4.5 (0.14) mmol/l basally to 1.5 (0.09) mmol/l [mean (sem), P < 0.003] at the hypoglycaemic reaction (‘R’) and recovered to baseline by ‘R’ + 60 min. There was an associated rise in plasma glucagon, adrenaline and noradrenaline levels. 3. Superior mesenteric artery blood flow rose at ‘R’ from a basal value of 532 (38) ml/min to a peak of 803 (73) ml/min at ‘R’+10 min [mean (sem), P < 0.005] and remained significantly elevated until ‘R’ + 40 min. Resistance in this vessel fell by 33% at ‘R’+ 10 min (P < 0.005) and remained significantly low until ‘R’ + 40 min. 4. Cardiac output rose by 33% at ‘R’ (P < 0.004) and returned to normal by ‘R’ + 20 min. This was associated with a 24% rise in pulse rate (P 0.03), but no change in stroke volume or mean arterial pressure. Total peripheral resistance fell by 21% at ‘R’ (P 0.005) and had returned to normal by ‘R’ + 20 min. 5. The sustained rise in splanchnic blood flow during hypoglycaemic recovery may be of homoeostatic importance by providing metabolic fuel to the liver for gluconeogenesis.

Increased splanchnic blood flow after hypoglycaemia in diabetic and normal man: evidence against glucagon as a mediator

“…This observation is in agreement with the findings of Braatvedt et al [1] in normal volunteers and suggests that patients with Type 1 diabetes have a normal splanchnic vascular hyperaemic response to hypoglycaemia. The absence of a plasma glucagon response to hypoglycaemia in the patients examined in this study was in accordance with previous studies, including that of Bolli et al [3], but was accompanied in all cases by significant increments in SMABF.…”

“…Mesenteric hyperaemia occurs in response to insulininduced hypoglycaemia in healthy young volunteers and a possible role in glucose homoeostasis has been suggested [1,2]. Mesenteric blood flow responses to hypoglycaemia in patients with Type 1 (insulin-dependent) diabetes mellitus have not been studied previously.…”

Hypoglycaemia induces decreased islet blood perfusion mediated by the central nervous system in normal and Type 2 diabetic GK rats

“…Our study shows that this is related to increased adrenal blood flow. Increased blood flow in the superior mesenteric artery occurs during insulin-induced hypoglycaemia [51].…”

Sonographic and Doppler assessment of the inferior mesenteric artery: normal morphologic and hemodynamic features

“…However, the Doppler approach offers the possibility to obtain qualitative and quantitative data on the functional aspects of these vessels in a totally noninvasive manner; for this reason, it is particularly suitable for investigating physiological splanchnic hemodynamics. It has already been used to investigate blood flow in the SMA under fasting and postprandial conditions [19,[22][23][24], during acute hypoglycemia [25], and after physical exercise [26]. Drug-induced modifications also have been studied in both adults and newborns [14,27].…”