Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Maintenance of the balance of electrolytes and hormones within their normal range is necessary for normal myocardial metabolism. Open heart surgery involving cardiopulmonary bypass produces metabolic disturbances which affect normal metabolic homeostasis. Several studies have suggested that pulsatile cardiopulmonary bypass causes less severe metabolic disturbance than non-pulsatile bypass and that non-pulsatile bypass causes hypofunction of the anterior pituitary and adrenal glands. The present study, however, with non-pulsatile flow showed that there was no evidence of hypothalamo-pituitary-adrenal axis hypofunction when the hormonal values of corticotrophin (ACTH), cortisol and cortisone were corrected for the hemodilution involved in cardiac surgery. Electrolytes, particularly calcium, play an important role in myocardial contractility. The levels of ionized calcium are normally controlled by parathyroid hormone (PTH) with a negative feedback of calcium controlling the system. However, this study showed that significant increases in bioactive PTH during cardiopulmonary bypass were not related to the calcium concentration, but appeared to be influenced by low blood pH values and by the degree of hypothermia.
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PMID:Hormonal and electrolyte responses during and after open heart surgery. 608 30

Normal myocardial function is dependent on the metabolic balance of a number of electrolytes and hormones. The calcium ion plays a major role in muscle contraction and is rigorously controlled within narrow limits. Open-heart surgery imposes metabolic disturbances on both electrolytes and hormones, especially ionized calcium. Normally, ionized calcium levels are controlled by parathyroid hormone with a negative feedback from the ionized calcium controlling the system, but the results from this study suggest that during open-heart procedures, ionized calcium does not impose its normal negative feedback on bioactive parathyroid hormone secretion. The low blood pH levels that occurred during the operative conditions of the patients studied and the level of hypothermia imposed on the circulating blood during cardiopulmonary bypass appeared to influence the control of parathyroid hormone secretion, causing high levels of hormone to be secreted during this period.
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PMID:The effect of ionized calcium, pH, and temperature on bioactive parathyroid hormone during and after open-heart operations. 661 69