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Titolo:
ALTERED VASOACTIVITY IN THE EARLY DIABETIC EYE - MEASURED IN THE ISOLATED-PERFUSED RAT EYE
Autore:
SU EN; YU DY; ALDER VA; YU PK; CRINGLE SJ;
Indirizzi:
UNIV WESTERN AUSTRALIA,LIONS EYE INST,CTR OPHTHALMOL & VISUAL SCI NEDLANDS WA 6009 AUSTRALIA UNIV WESTERN AUSTRALIA,LIONS EYE INST,CTR OPHTHALMOL & VISUAL SCI NEDLANDS WA 6009 AUSTRALIA
Titolo Testata:
Experimental Eye Research
fascicolo: 6, volume: 61, anno: 1995,
pagine: 699 - 711
SICI:
0014-4835(1995)61:6<699:AVITED>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
RETINAL RESISTANCE ARTERIES; LASER DOPPLER VELOCIMETRY; MESENTERIC VASCULAR BED; VITREAL OXYGEN-TENSION; CILIARY ARTERIES; BLOOD-FLOW; ADRENERGIC RESPONSES; ANGIOTENSIN-II; CAT EYE; BOVINE;
Keywords:
DIABETES; VASCULAR RESISTANCE; ISOLATED PERFUSED EYE; RAT, CATECHOLAMINES; 5-HT; PROSTAGLANDINS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
58
Recensione:
Indirizzi per estratti:
Citazione:
E.N. Su et al., "ALTERED VASOACTIVITY IN THE EARLY DIABETIC EYE - MEASURED IN THE ISOLATED-PERFUSED RAT EYE", Experimental Eye Research, 61(6), 1995, pp. 699-711

Abstract

The effect of 4 weeks streptozotocin-induced diabetes on ocular vascular resistance responses to noradrenalin (NA), adrenalin (A), phenylephrine (PHE), isoproterenol (ISOP), prostaglandin F-2 alpha(PGF(2 alpha)). 5-hydroxytryptamine (5-HT) and angiotensin II (ANG II), was determined using a newly-developed, isolated, arterially-perfused rat eye preparation, by comparing responses from control and diabetic eyes. After extensive preliminary experiments to establish optimum parameters, the ophthalmic artery of enucleated control and diabetic rat eyes was cannulated and the retinal and uveal vasculature perfused at a constantnow with Na+-Krebs solution after streptozotocin-induced diabetes hadbeen established for 4 weeks. The eyes were maintained in an environment-controlled organ bath. Perfusion pressure was monitored as increasing log M concentrations of agonists were added to the perfusate. Total ocular resistance could be calculated from knowledge of now and pressure. In control eyes, NA, A, PHE, PGF(2 alpha), and 5-HT all produceddose-dependent increases in total vascular resistance, with the following order of potency: NA = A > 5-HT > PHE = PGF(2 alpha) at 10(-4) M. The ocular circulation was not sensitive to isoproterenol and angiotensin II. In diabetic eyes responses to NA, A, PGF(2 alpha) and 5-HT were altered. Diabetic responses to NA and A had lower thresholds with larger resistance increases at low concentrations. However, the rate ofincrease in resistance with concentration was more gradual in diabetic eyes so that at 10-(4) M control responses were larger. Diabetic resistance responses to PGF(2 alpha), had the same threshold as in control eyes, but were greater in magnitude with an earlier peak at 10(-4) M. In contrast diabetic resistance responses to 5-HT were reduced, peaked at a lower resistance at 10(-4) M, but had the same threshold as those in the control eye. Basal vascular resistances in control: 3.14 +/- 0.32 mmHg min mu l(-1) (n = 28), and diabetic eyes: 3.44 +/- 0.19, mmHg min mu l(-1) (n = 36), were not significantly different. Vasoactivity in the early diabetic eye is disturbed with the effective balance between different agonists altered in favour of catecholamines at physiological concentrations. This may be related to the early changes in blood now and oxygen distribution already reported in the rat eye, as well as changes to autonomic function. The isolated perfused rat eye is a valuable technique for investigating such vascular reactivity in animal models of retinal disease. (C) 1995 Academic Press Limited

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/09/20 alle ore 11:58:35