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Titolo:
Size-dependent effects of microspheres on vasoconstrictor-mediated change in oxygen uptake by perfused rat hindlimb
Autore:
Vincent, MA; Rattigan, S; Clark, MG;
Indirizzi:
Univ Tasmania, Sch Med, Div Biochem, Hobart, Tas 7001, Australia Univ Tasmania Hobart Tas Australia 7001 chem, Hobart, Tas 7001, Australia
Titolo Testata:
MICROVASCULAR RESEARCH
fascicolo: 3, volume: 62, anno: 2001,
pagine: 306 - 314
SICI:
0026-2862(200111)62:3<306:SEOMOV>2.0.ZU;2-Q
Fonte:
ISI
Lingua:
ENG
Soggetto:
SKELETAL-MUSCLE; BLOOD-FLOW; CAPILLARY RECRUITMENT; SEROTONIN; INSULIN; THERMOGENESIS; METABOLISM; INHIBITION;
Keywords:
microembolism of muscle blood flow; nutritive flow; nonnutritive flow; two circulatory systems in muscle;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Clark, MG Univ Tasmania, Sch Med, Div Biochem, GPO Box 252-58, Hobart, Tas7001, Australia Univ Tasmania GPO Box 252-58 Hobart Tas Australia 7001 Australia
Citazione:
M.A. Vincent et al., "Size-dependent effects of microspheres on vasoconstrictor-mediated change in oxygen uptake by perfused rat hindlimb", MICROVASC R, 62(3), 2001, pp. 306-314

Abstract

There are two vascular flow routes in skeletal muscle that can be accessedby different vaso constrictors acting at selective sites in the vascular tree. Thus, angiotensin II (AII) and serotonin (5-HT), which stimulate and inhibit metabolism, do so by directing flow to nutritive and nonnutritive routes, respectively. In the present study the association between vascular flow route recruitment and metabolism was assessed by embolism with microspheres of different sizes. Latex microspheres (MS) of four sizes, 5.4 (MS5), 11.8 (MS12), 23.4 (MS23), and 93.6 mum (MS94), were injected during AII- or5-HT-mediated constriction or under basal conditions and the effects on hindlimb oxygen uptake (VO2), perfusion pressure, and venous flow rate were determined. MS5 or MS12 partially reversed 5-HT-mediated inhibition of VO2 by 39 and 55%, respectively (P < 0.05), fully reversed All-mediated stimulation of VO2 (P < 0.05), stimulated basal VO2 (P < 0.05), and increased pressure while only marginally (< 10%) decreasing venous flow. MS23 or MS94 dose-dependently increased pressure and inhibited VO2, during basal or 5HT- andAll-mediated constriction, while only marginally decreasing venous flow. In conclusion, microspheres of less than 12 mum when injected into the constant flow perfused rat hindlimb can alter metabolism by altering flow distribution between nutritive and nonnutritive routes. Larger MS (greater than or equal to 24 mum) are nondiscriminating possibly because they exceed the size of vessels in which branch points to the two vascular routes are located. Overall the findings provide further evidence for two microvascular routes in muscle, one nutritive and the other nonnutritive, (C) 2001 Academic Press.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/11/20 alle ore 14:58:33