Hemodynamic studies in DOCA-salt hypertensive rats after opening of an arteriovenous fistula.
We determined the cardiovascular responses in normal and deoxycorticosterone acetate (DOCA)-salt hypertensive rats with reduced total peripheral resistance due to an arteriovenous (a-v) fistula. Animals were divided into four groups: control, fistula, DOCA-salt, and DOCA-salt fistula. The fistula was made by anastomosing the aorta and vena cava below the renal arteries. Four weeks after the creation of the fistula both DOCA-salt and DOCA-salt fistula animals received DOCA and salt for 6-8 wk. At the end of 10-12 wk we measured mean arterial pressure, cardiac output, tissue flows, and right atrial pressure. Flow measurements using radioactive microspheres were made in anesthetized animals. Cardiac index (CI) was 202% higher in the fistula group than in the control animals and 165% higher in the DOCA-salt fistula than in the DOCA-salt animals. There was no difference in cardiac output between the control and DOCA-salt animals. The increase in cardiac output was due to the fistula flow as evidenced by a significant increase in the number of microspheres in the lung. Mean arterial pressure was 115 +/- 4 mmHg (control) and 108 +/- 5 mmHg (fistula) in non-DOCA rats but increased in both DOCA groups, 159 +/- 3 mmHg (DOCA-salt) and 145 +/- 5 mmHg (DOCA-salt fistula). Right atrial pressure was increased above control in both fistula animals but was normal in DOCA-salt animals. Total peripheral resistance (TPR) was higher than control in DOCA-salt animals, but TPR in both the fistula and DOCA-salt fistula animals was lower than control.(ABSTRACT TRUNCATED AT 250 WORDS)
Huang
M
M
Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson 39216.
Hester
R L
RL
Guyton
A C
AC
Norman
R A
RA
D000818:Animals; D001164:Arteriovenous Fistula / Q000150:complications / Q000503:physiopathology*; D001826:Body Fluids / Q000378:metabolism; D001835:Body Weight; D003900:Desoxycorticosterone; D006339:Heart Rate; D006439:Hemodynamics; D006728:Hormones / Q000097:blood; D006973:Hypertension / Q000139:chemically induced / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D007668:Kidney / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D009929:Organ Size; D051381:Rats; D012077:Renal Artery / Q000503:physiopathology; D012079:Renal Circulation; D012965:Sodium Chloride; D014655:Vascular Resistance
D006728:Hormones; D003900:Desoxycorticosterone; D012965:Sodium Chloride