IGNIFICANCE OF GLUCOCORTICOID IN PREVENTINGHYPERCALCEMIC SHOCK IN RABBITS
| Autor: | Tokuro Fukuda, Junichiro Ui |
|---|---|
| Rok vydání: | 1967 |
| Předmět: |
medicine.medical_specialty
Physiology chemistry.chemical_element Blood Pressure Autopsy Vagotomy Calcium Dexamethasone Calcium Chloride Cerebrospinal fluid Internal medicine medicine.artery medicine Animals Infusions Parenteral Glucocorticoids Respiration Adrenalectomy Shock General Medicine Endocrinology chemistry Blood-Brain Barrier Shock (circulatory) Calcium concentration Right heart Pulmonary artery Hypercalcemia Potassium Rabbits medicine.symptom Glucocorticoid medicine.drug |
| Zdroj: | The Japanese Journal of Physiology. 17:589-598 |
| ISSN: | 1881-1396 0021-521X |
| DOI: | 10.2170/jjphysiol.17.589 |
| Popis: | It has been observed that adrenalectomized rabbit are extremely susceptible to hypercalcemia. Intravenous infusion of CaCl2 solution induced easilya lethal hypotention accompanied by cyanosis before cardiac disturbancesdue to extreme hypercalcemia ensued. Autopsy showed a pronounced dilatation of pulmonary artery and right heart, suggesting pulmonary arteriolarspasm. Examination of the cerebrospinal fluid in the shocked state revealeda marked elevation of calcium concentration. In intact animals no suchelevation occurred and cardiac death followed in extreme hypercalcemia.Intracisternal injection of small amounts of CaCl2 solution in intact animalswas found to induce a quite similar type of shock observed in adrenalectomizedanimals in hypercalcemia. Thereby, bilateral cervical vagotomy could preventthe appearance of the shock, indicating that the shock was due to activationof pulmonary vagal vasoconstrictors.Pretreatment with glucocorticoid which completely reversed the increasedsusceptibility of adrenalectomized rabbits to intravenous infusion of CaCl2 solution was found also effective in preventing the entrance of calcium ioninto the cerebrospinal fluid. Thus it has been deduced that the hypercalcemicshock in the absence of glucocorticoid might be the result of the enhancedpermeability of the blood-cerebrospinal fluid barrier to calcium ion. Thesignificance of glucocorticoid for the maintenance of blood-cerebrospinal fluidbarrier and the central action of calcium ion in this animal species havebeen discussed. |
| Databáze: | OpenAIRE |
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