Hormonal Dependence of the Effects of Metabolic Encephalopathy on Cerebral Perfusion and Oxygen Utilization in the Rat
| Autor: | E. Kozniewska, Allen I. Arieff, John Kucharczyk, Timothy P.L. Roberts, Zinaida S. Vexler, M. Oseka |
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| Rok vydání: | 1995 |
| Předmět: |
Male
medicine.medical_specialty Vasopressin Physiology Encephalopathy Hemodynamics Blood Pressure Oxygen Consumption Internal medicine medicine Animals Deamino Arginine Vasopressin Cerebral perfusion pressure Desmopressin Brain Diseases business.industry Sodium Brain nutritional and metabolic diseases Estrogens medicine.disease Magnetic Resonance Imaging Rats Arginine Vasopressin Blood pressure Endocrinology Cerebral blood flow Cerebrovascular Circulation Chronic Disease Potassium Female Sex Cardiology and Cardiovascular Medicine Hyponatremia business hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Circulation Research. 76:551-558 |
| ISSN: | 1524-4571 0009-7330 |
| Popis: | Abstract Previous studies have demonstrated that in adult rats with chronic hyponatremia, both symptoms of encephalopathy and mortality largely depend upon the gender of the animal and the presence of elevated plasma levels of vasopressin (AVP). Since effects of AVP on blood vessels may be gender dependent, the present study was designed to compare the effects of chronic (4 days) hyponatremia on cerebral blood flow (CBF), cerebral oxygen consumption (CMRO 2 ), and cerebral perfusion index (CPI) in adult male and female rats. CBF (intra-arterial 133 Xe injection method) and CMRO 2 (arteriovenous difference of cerebral oxygen content×CBF) were measured in normonatremic and hyponatremic (hyponatremia induced with 140 mmol/L glucose and either AVP or desmopressin [dDAVP], plasma sodium=100 to 110 mmol/L) adult rats of both genders. The CPI was assessed from magnetic resonance imaging of the transit of magnetic susceptibility contrast agent through the brain. Female rats with AVP-induced chronic hyponatremia had a 36% decrease in CBF and a 60% decrease in CMRO 2 . In male animals, both parameters were not different from control values. AVP-induced hyponatremia resulted in a 45% decrease in CPI in female rats, but hyponatremia induced with dDAVP did not affect CPI in either male or female rats. Chronic (4 days) administration of AVP did not affect CPI in either male or female normonatremic rats. When rats with AVP-induced chronic hyponatremia were pretreated with estrogen, the CPI in males was not different from that in females. Our results demonstrate that during AVP-induced chronic hyponatremia in female rats, there is significant depression of both oxygen utilization and blood flow in the brain. |
| Databáze: | OpenAIRE |
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