The dry fruits of Hippophae rhamnoides (so-called "Saji" or "Sea buckthorn") are used in China as a herbal medicine. The present work studied the effects on microvessels in the left ventricular wall, hematological parameters, cardiovascular performance and plasma constituents in spontaneously hypertensive stroke-prone rats (SHRSP/EZO) treated with Hippophae for 60 days. Analyses showed that the powder made of dry Hippophae fruits contains the vitamins C, B1, B2 and E, provitamin A, rutin, serotonin, cytosterol, selenium and zinc, among other constituents. The experimental rats were fed ad libitum with blocks of rat chow supplemented with Hippophae powder at a concentration of 0.7 g/kg in rat powder chow, while control rats were unsupplemented chow. The mean arterial blood pressure, heart rate, total plasma cholesterol, triglycerides, and glycated hemoglobin were significantly decreased by the Hippophae treatment. The arteriolar capillary portions of microvessels expressing alkaline phosphatase decreased, but there was a trend for an increase in the total capillary density. It was concluded that Hippophae fruits improved the metabolic processes accompanied by reduction of hypertensive stress on the ventricular microvessels.