Accession Number:

AD0410779

Title:

CARDIOVASCULAR EFFECTS OF NOREPINEPHRINE THERMO GENESIS IN WARM- AND COLD-ACCLIMATIZED RATS,

Descriptive Note:

Corporate Author:

ARCTIC AEROMEDICAL LAB FORT WAINWRIGHT ALASKA

Personal Author(s):

• Evonuk,Eugene
• Hannon,John P.

Report Date:

1962-03-01

Pagination or Media Count:

1.0

Abstract:

The cardiovascular and metabolic actions of nore pinephrine NE and their interrelationships were studied at normal room temperature in anesthe tized, warm-acclimatized W-A 26 1 C and cold-acclimatized C-A 3 1 C rats. Norepine phrine caused a greater increase in the cardiac output, heart rate, stroke volume and right atri al pressure in the C-A animals than it did in the W-A animals. During the early metabolic response to NE i.e. up to 25 increase in O2 consumption there was a marked increase in the arterial pres sure of both W-A and C-A rats, with the latter showing the greater maximum response. Beyond the 25 level of increased metabolism the arterial pressure and concomitantly the systemic resistance of the C-A animals declined sharply to the prein fusion levels, where they remained throughout the course of infusion. In contrast, the arterial pressure and systemic resistance of the W-A animals remained high. It was concluded that norepinephrine calorigenesis in the C-A rat is supported by an increased cardiac reserve capacity and an ability to preferentially reduce the sys temic resistance to actively metabolizing areas. i.e. the viscera. Author

Descriptors:

• *RATS
• *HYPOTHERMIA
• ACCLIMATIZATION
• METABOLISM
• TEMPERATURE
• HEART
• BLOOD CIRCULATION
• BLOOD PRESSURE
• NOREPINEPHRINE

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE