Does so-called streptozocin hypertension exist in rats?

Area of Science:

• Physiology
• Pharmacology
• Cardiovascular Research

Background:

• The existence of streptozocin-induced hypertension is widely accepted.
• However, some studies report no significant blood pressure increase after streptozocin administration.
• This discrepancy necessitates a re-evaluation of streptozocin's hypertensive effects.

Purpose of the Study:

• To accurately assess the impact of streptozocin on blood pressure in different rat models.
• To compare direct and indirect blood pressure measurement techniques in streptozocin-treated rats.
• To determine if streptozocin reliably induces hypertension.

Main Methods:

• Normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were administered streptozocin intravenously.
• Direct mean blood pressure was measured via abdominal aortic cannula without anesthesia.
• Indirect tail-cuff blood pressure was measured without anesthesia after prewarming.

Main Results:

• Indirect blood pressure increased in WKY rats post-streptozocin, but direct measurements showed a decrease.
• Direct blood pressure in SHR rats decreased significantly after streptozocin treatment.
• Discrepancies were attributed to rat emaciation affecting indirect BP readings.

Conclusions:

• Direct blood pressure measurement is more reliable than indirect measurement in emaciated diabetic rats.
• The findings suggest that "streptozocin hypertension" may not exist under the studied conditions.
• Streptozocin treatment does not consistently induce hypertension; direct measurement is crucial for accurate assessment.