Male albino rats were chronically loaded with sodium by giving 1% NaCl solution as the sole source of drinking water. Daily fluid intake, daily urinary output and daily Na+ and K+ excretion rates were compared with control rats receiving tap water for six weeks. At the end ofsix weeks, sodium loaded animals were found to have raised plasma Na+ concentration, lowered plasma K+ concentration and lowered haematocrit value. Sodium loaded rats were also significantly more responsive to the pressor effect of submaximal doses of adrenaline, noradrenaline and angiotensin II given intravenously. It is concluded that the increase in sensitivity to adrenaline and noradrenaline may be due to changes in EGF and alterations of plasma electrolytes concentration. For angiotensin II, additionally, it may be due to low circulating endogenous angiotensin II, consequent of reduction in renin release attributed to chronic sodium loading.
Singapore is a small Southeast Asian island city-state located at the tip of the Malay peninsula with a population of 5.61 million people. It was a former British colony that went on to become a part of Malaysia before gaining independence in 1965. Since then, Singapore has developed tremendously from a small fishing village into the region's medical hub. This article will explore the roots of cardiac anesthesia in Singapore and how it has developed into a subspecialty today.