Methods for isolation, cannulation, and in vitro study of single microvessels

Abstract

A method is described for the isolation and cannulation of microvessels (12-112 micrometers) that permits study, in vitro, of their physiology and pharmacology. Vessels from the hamster cheek pouch, testis, and mesentery and from rat brain have been isolated at 4 degrees C with specially prepared instruments and viewed with an inverted microscope. The vessels were cannulated at one end by equipment developed for renal tubular perfusion. The uncannulated end of the vessel is sealed, and experiments on reactivity and mechanics are carried out at fixed intravascular pressures. The isolated microvessels studied have a modulus of elasticity that is consistent with that observed in large vessels, and they display similar maximal active tension development (approximately 10(6) dyn/cm2). Reactivity to norepinephrine, acetylcholine, and adenosine are in the normal range for microvessels. Spontaneous tone is present, as evidenced by stable tonic contractions as well as phasic contractions in the frequency range of 3-30/min. The vessels display stress activation (myogenic response) consisting of contraction in response to increased intraluminal pressure. Our findings suggest that this preparation will be very useful in elucidating the physiology and pharmacology of the resistance vessels in the terminal vasculature.

Reduced EDHF responses and connexin activity in mesenteric arteries from the insulin-resistant obese Zucker rat

“…Briefly, a section of the mesenteric bed was pinned flat in a cooled (4°C) chamber containing dissection buffer (3 mmol/l 3-[N-morpholino]propanesulfonic acid, 1 mmol/l NaH 2 PO 4 , 5 mmol/l glucose, 2 mmol/l pyruvate, 0.02 mmol/l EDTA, 145 mmol/l NaCl, 5 mmol/l KCl, 2.5 mmol/l CaCl 2 , 1 mmol/l MgSO 4 , 1% (wt/vol.) BSA, pH 7.4) [29]. A third-order mesenteric artery was isolated and mounted between two glass cannulas (tip diameter approximately 50 μm) in a 5 ml chamber.…”

Ca2+ signaling in mouse mesenteric small arteries: myogenic tone and adrenergic vasoconstriction

“…Isolated arteries were dissected using methods similar to those described previously (4). Dissected segments of the third-order arteries, 1-2 mm in length, were transferred to a recording chamber, where their ends were mounted on glass pipettes (tip diameter 60 -100 m) and secured by 10-0 Ethilon ophthalmic nylon sutures (Ethicon, Somerville, NJ).…”

Inhibition of the active lymph pump by flow in rat mesenteric lymphatics and thoracic duct

“…Once thoroughly cleaned of all surrounding tissues, the lymphatic segment was cut and transferred to a chilled well (0-4°C), where the lymphatic was prepared using modifications of techniques originally developed in arterioles (Duling et al 1981;Gore & Davis, 1984;Osol & Halpern, 1985;Kuo et al 1988. The microscope stage plate used for cannulating the vessel was filled with an albumin-enriched physiological salt solution (APSS) (mM: 145.00 NaCl, 4.7 KCl, 2.0 CaCl 2 , 1.17 MgSO 4 , 1.2 NaH 2 PO 4 , 5.0 dextrose, 2.0 sodium pyruvate, 0.02 EDTA, 3.0 Mops and 10 g l _1 bovine serum albumin) and chilled to 0-4°C.…”