[Cardiac output and its distribution in waking rats with acute streptozotocin diabetes]

Cardiac output and its regional distribution were studied in conscious rats with acute 24-hour streptozotocin (STZ)-induced diabetes using the labeled microsphere technique. Rats were made diabetic with a single intravenous injection of STZ (60 mg/kg). One day post-STZ all rats were divided into two groups in accordance with the results of urine analysis: rats with ketonuria (n = 6) and rats without ketonuria (n = 7). All the experimental animals had similar blood glucose concentration 24 hours after STZ-injection: 408 +/- 15 and 421 +/- 16 mg/100 ml in rats with and without ketonuria, respectively. All STZ-treated rats showed significant alterations in the systemic hemodynamics one day post-STZ. They included a slight hypotension, a decrease in the total peripheral resistance (TPR) and an increase in the cardiac index (CI) and stroke volume (SV) compared to pre-injection level. Rats with ketonuria showed more prominent decrease in TPR (57 +/- 6 vs. 38 +/- 4% in rats without ketonuria, p < 0.05) and more prominent increase in CI (102 +/- 18 vs. 41 +/- 8% in rats without ketonuria, p < 0.05) and SV (105 +/- 19 vs. 32 +/- 10% in rats without ketonuria, p < 0.05). In both experimental groups the blood flow was significantly increased in the small intestine, heart, brain and kidneys compared to preinjection level. Additionally, rats with ketonuria had increased blood flow in the skin and skeletal muscle (by 0.076 +/- 0.019 and 0.056 +/- 0.020 ml/min/g, respectively, p < 0.05).