Quantitative image analysis of choroid and retinal vasculature in SHR: a model of cerebrovascular hypertensive changes?
Retinal and choroids arteries changes were investigated ophthalmoscopically and with morphometric techniques in spontaneously hypertensive rats (SHR) of 26 weeks either untreated (control animals) or treated for 12 weeks equi-hypotensive doses of the Ca2+ antagonist nicardipine or of the non-dihydropyridine type vasodilatator hydralazine. Retinal and choroid arteries hypertensive changes were compared with those affecting pial and intracerebral arteries of frontal lobe. Ophthalmoscopic analysis revealed in control SHR a rarefaction of capillaries and a decrease of their length and area. Treatment with nicardipine and to a lesser extent with hydralazine countered ophthalmoscopic changes noticeable in SHR. Morphometric analysis revealed thickening of the wall and luminal narrowing of retinal, choroids, pial, and intracerebral arteries. Anti-hypertensive treatment decreased thickening of the arterial wall and increased luminal narrowing of different arteries investigated. Nicardipine was more effective than hydralazine in countering arterial hypertensive changes in SHR and displayed a vasodilatory activity on small sized retinal and cerebral arteries, that represent a vascular segment not sensitive to hydralazine. Comparative evaluation of the wall-to-lumen ratio revealed a similar pattern between retinal and intracerebral arteries, but not between other arteries investigated. This suggests that analysis of retinal arteries may be predictive of brain intracerebral arteries changes in hypertension.
Tomassoni
Daniele
D
Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, 62032 Camerino, Italy
Mancinelli
Giulio
G
Mignini
Fiorenzo
F
Sabbatini
Maurizio
M
Amenta
Francesco
F
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002536:Cerebral Arteries / Q000187:drug effects / Q000473:pathology; D002561:Cerebrovascular Disorders / Q000150:complications / Q000188:drug therapy*; D015862:Choroid Diseases / Q000150:complications / Q000188:drug therapy*; D004095:Dihydropyridines / Q000494:pharmacology; D004195:Disease Models, Animal; D006830:Hydralazine / Q000494:pharmacology; D008297:Male; D009529:Nicardipine / Q000494:pharmacology; D009798:Ocular Hypertension / Q000150:complications / Q000188:drug therapy*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012161:Retinal Artery / Q000187:drug effects / Q000473:pathology; D013599:Systole / Q000187:drug effects; D016896:Treatment Outcome
D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D006830:Hydralazine; D009529:Nicardipine