抄録
2-deoxy-D-glucose (2DG; for blockade of glycolysis) and alpha-melanocyte stimulating hormone (alpha-MSH) were employed to induce hypothermia in conscious rats. Wistar rats were instrumented chronically with electrodes for measurements of intra-abdominal temperature (Tab), renal sympathetic nerve activity (RSNA), the electrocardiogram and electromyogram, and catheters for systemic arterial and central venous pressures. At least 2 days after surgery, the rats were placed in the temperature controlled metabolic chamber where heat production, Tab, RSNA and hemodynamic functions were monitored continuously. After intravenous (iv) administration of 2DG (750mg/kg), Tab decreased significantly (p<0.05) to a nadir of 2.8 oC at 73 min after the administration while heat production remained unchanged throughout the experimental period and heart rate was markedly suppressed by 119 beats/min at 74 min after the 2DG administration. In a separate series of experiment, 8 nmol of alpha-MSH in saline solution was injected into the right lateral ventricle (icv). The Tab decreased immediately to stabilize at 1.6 oC at 69 min after the administration; heat production did not change significantly (p<0.05), and heart rate decreased by 124 beats/min (p<0.05) at 33 min. After both 2DG (iv) and alpha-MSH (icv) administration, there was a consistent reduction of Tab without changes in heat production, suggesting that heat loss increased. It is therefore likely that the drug-induced hypothermia was a consequence of acute modification of thermoregulatory system. [Jpn J Physiol 54 Suppl:S57 (2004)]
