Effects of Ginkgo biloba extract (EGb 761) on the guinea pig vestibular system.

Previous studies have demonstrated that the administration of Ginkgo biloba extract (EGb 761) improves the compensation of the vestibular syndrome induced by transection of the VIIIth nerve. To investigate the mechanisms at play, the vestibular nuclei of alert guinea pigs were perfused with EGb 761. This perfusion always induced a stereotyped reversible postural syndrome that was the mirror image of the syndrome provoked by the unilateral lesion of the otolithical receptors.

[Protective effect of cicletanine in hypertensive retinopathy. Evaluation of retinal function in the isolated retina].

In order to demonstrate functional impairments related to hypertensive retinopathy, we experimented on the isolated retina of spontaneously hypertensive rats (SHR-SP strain A3N Iffa Credo). We also used this experimental model to assess the protective effect of treatment with cicletanine, a new synthetic furopyridine compound. Treatment consisted of daily oral administration of either 50 or 100 mg/kg of cicletanine for 5 weeks.

Antihypertensive profile of cicletanine, a furopyridine derivative: comparison with captopril, indapamide and prazosin.

The effects of cicletanine were compared with those of three other antihypertensive drugs: prazosin, a highly selective alpha 1 antagonist, captopril an angiotensin converting enzyme inhibitor and indapamide a diuretic antihypertensive agent, on young stroke-prone SHR rats with high salt diet; furthermore, vascular reactivity to cicletanine was studied on isolated rat aorta. At an equal dose (30 mg/kg per os) all the drugs prevent the onset of hypertension with the same intensity. The minimal effective dose on blood pressure was 1 mg/kg for both cicletanine and captopril, and 3 mg/kg for indapamide.

Comparison of cicletanine with other antihypertensive drugs in SHR-SP models.

The effects of cicletanine were compared with those of four other antihypertensive drugs (prazosin, a highly selective alpha 1 antagonist; captopril, an angiotensin-converting enzyme inhibitor; indapamide, an antihypertensive diuretic; and hydrochlorothiazide, a purely diuretic agent) on young stroke-prone SHR rats with high-salt diet. All the drugs except hydrochlorothiazide prevented the onset of hypertension. The minimal effective dose on blood pressure was 1 mg/kg for both cicletanine and captopril, and 3 mg/kg for indapamide.