Quantitative Measurement of Fixation Rate and Dimension Changes in the Aldehyde/Pressure-Fixed Canine Carotid Artery

Kratky, Ralph G.; Lo, D.; Roach, Margot R.

doi:10.1159/000158885

Cited by 10 publications

(5 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, studies done in vivo and enhanced extracellular matrix involving principally colLrotid preparations involving interruption of flow and lagen (Cox, 1979;Milnor, 1982;Dobrin, 1983; Nichols & -ing static (and not pulsatile) pressure-diameter re-O' Rourke, 1990;Levy et al, 1994). Our present histomorhips have extensively shown that acute and long-term phometric findings in placebo-treated WKY and SHR were i-blockade relaxes arterial smooth muscle and increases obtained from the classical perfusion-fixation technique and compliance at any given value of transmural pressure were very similar to those previously reported in the literature umi et al, 1989;London et al, 1992;Levy et al, 1993;(Owens, 1985;Kratky et al, 1991;Benetos et al, 1993; Levy et The last possibility to consider is that the factors inal., 1994). Following chronic calcium blockade, decreased ig the present pulsatile pressure-diameter relationship medial thickness was observed in association with a substantial tly different from those modulating the static pressurereduction in elastin and collagen content, which however did whereas dilation transfers stresses to the elastic lamellae.…”

Section: Discussionsupporting

confidence: 89%

Influence of graded changes in vasomotor tone on the carotid arterial mechanics in live spontaneously hypertensive rats

Lacolley

Ghodsi

Glazer

et al. 1995

British J Pharmacology

View full text Add to dashboard Cite

1 The contribution of vasomotor tone to the increased stiffness of carotid arteries in living spontaneously hypertensive rats (SHR) is largely unknown. Whether a reduced vascular tone is associated with an increase or a decrease in arterial stiffness in vivo remains to be determined. The goal of the present investigation was to show that a decrease in vascular tone is associated with a decrease in arterial stiffness, independent of the structural composition of the arterial wall. 2 New high resolution echo-tracking techniques were used to evaluate pulsatile changes of carotid blood pressure and diameter following transient and graded changes of vasomotor tone produced by the dihydropyridine derivative, isradipine. Treatment for 8 weeks was given to groups of SHR rats either with a low (0.6 kg day-') or a high (2.6 mg kg-l day-') dose. Another SHR group received an acute dose of 2.6 mg kg-' day-'. Results were compared to those of placebo-treated Wystar-Kyoto (WKY) and SHR rats. Whatever the dosage, acute or chronic calcium blockade caused a decrease in blood pressure which was maximal 1 h after administration and disappeared after the 16th h. Carotid arterial thickness and the composition of the arterial wall was determined from histomorphometry. 3 In placebo-treated SHR, the inverse relationship relating blood pressure to carotid arterial distensibility was significantly shifted toward higher values of blood pressure compared to the curve of normotensive placebo-treated WKY rats. The curve of SHR receiving chronically a non antihypertensive (0.6 mg kg`' day-') isradipine dose prolonged that of placebo-treated SHR toward lower values of blood pressure, so that carotid distensibility was significantly higher than in WKY for the same diameter and blood pressure level (145 mmHg). With administration of a chronic antihypertensive dose (2.6 mg kg-' day-') causing a significant decrease in arterial thickness, the curve of SHR was transiently shifted towards the WKY curve, resulting in a normal arterial function. Acute antihypertensive calcium blockade with a single isradipine dose (2.6 mg kg-' day-') caused a similar shift in the pressure-distensibility curve toward the WKY curve although the histomorphometric composition of the arterial wall differed significantly from that of chronically treated animals. 4 The study provides evidence that, in living SHR submitted to calcium blockade, (i) a low dose of isradipine causing no substantial antihypertensive effect is associated with a significant elevation of carotid arterial distensibility for the same pressure and diameter as normotensive controls, and (ii) an acute or chronic dose causing a substantial antihypertensive effect is associated with a transient shift of the SHR distensibility-pressure curve toward a physiological arterial function, increasing carotid distensibility for the same pressure and diameter as WKY controls. Since such findings were observed independently of the histomorphometric composition of the arterial wall, they imply that the transient decre...

show abstract

Section: Discussionsupporting

confidence: 89%

Influence of graded changes in vasomotor tone on the carotid arterial mechanics in live spontaneously hypertensive rats

Lacolley

Ghodsi

Glazer

et al. 1995

British J Pharmacology

View full text Add to dashboard Cite

show abstract

“…After 1 or 2 minutes, a clamp was positioned on the atrium, and the fixation liquid was infused for 3 hours at a pressure equal to the MBP of each animal. 30 At the end of the perfusion, the thoracic aorta was dissected and preserved in a 4% formaldehyde solution until the histological study was performed.…”

Section: Morphological Studymentioning

confidence: 99%

“…30 For reasons explained in "Methods," the CSA rather than the thickness of the aortic media was chosen for evaluation of arterial hypertrophy. In the present study, the placebo-treated animals developed, as expected, significant medial aortic hypertrophy, with CSA values comparable to those observed in SHR of the same age.…”

mentioning

confidence: 99%

Angiotensin converting enzyme inhibition prevents the increase in aortic collagen in rats.

et al. 1994

View full text Add to dashboard Cite

Four groups of 4-week-old spontaneously hypertensive rats were treated during 4 months with the angiotensin converting enzyme inhibitor quinapril at 1 mg/kg per day (Ql) or 10 mg/kg per day (Q10), hydralazine at 15 mg/kg per day (H), or placebo (P). In the first set of experiments, blood pressure was measured in conscious rats, and plasma and aortic angiotensin converting enzyme activities were evaluated. In the second set of experiments, histomorphometric parameters of the thoracic aorta were evaluated. Mean blood pressure was lower in the Q10 and H groups (136±16 and 149±11 mm Hg) compared with the P group (190±23 mm Hg) (P<.01). The Ql group showed mean blood pressure values (171 ±15 mm Hg) lower than the P group (P<.05) but significantly higher than the Q10 and H groups (P<.01 and P<.05, respectively). Aortic medial cross-sectional area was significantly lower in the H and Q10 groups (455 ±61 and 487±57 x 10 3 jun 2 ) than in the P group (636±72 /mm of aorta). Aortic angiotensin converting enzyme activity was inhibited by approximately 60% in both groups treated with quinapril, whereas plasma angkrtension converting enzyme activity was reduced only in the Q10 rats. These results show that, whereas both hydralazine and quinapril prevented the development of aortic hypertrophy in a pressure-dependent manner, the prevention of the increase in aortic collagen was observed only after quinapril treatment. This latter effect of angiotensin converting enzyme inhibition was not related to the blood pressure reduction but was associated with the reduction of aortic and not plasma converting enzyme.

show abstract

“…However, local pressures may become very high, causing vascular distension (Hodde & Nowell, 1980). Perfusion fixation before vascular casting can reduce such distension (Kratky et al, 1991), but at the risk of shrinking the vasculature or resulting in less complete casts (Reddy et al, 1995). We therefore chose to infuse the resin under pressure-controlled conditions, maintaining the input pressure at physiological levels.…”

Section: Discussionmentioning

confidence: 99%

Optimization of Vascular Casting for Three-Dimensional Fluorescence Cryo-Imaging of Collateral Vessels in the Ischemic Rat Hindlimb

et al. 2017

View full text Add to dashboard Cite

Development of collateral vessels, arteriogenesis, may protect against tissue ischemia, however, quantitative data on this process remain scarce. We have developed a technique for replicating the entire arterial network of ischemic rat hindlimbs in three dimensions (3D) based on vascular casting and automated sequential cryo-imaging. Various dilutions of Batson's No. 17 with methyl methacrylate were evaluated in healthy rats, with further protocol optimization in ischemic rats. Penetration of the resin into the vascular network greatly depended on dilution; the total length of casted vessels below 75 µm was 13-fold higher at 50% dilution compared with the 10% dilution. Dilutions of 25-30%, with transient clamping of the healthy iliac artery, were optimal for imaging the arterial network in unilateral ischemia. This protocol completely filled the lumina of small arterioles and collateral vessels. These appeared as thin anastomoses in healthy legs and increasingly larger vessels during ligation (median diameter 1 week: 63 µm, 4 weeks: 127 µm). The presented combination of quality casts with high-resolution cryo-imaging enables automated, detailed 3D analysis of collateral adaptation, which furthermore can be combined with co-registered 3D distributions of fluorescent molecular imaging markers reflecting biological activity or perfusion.

show abstract

Quantitative Measurement of Fixation Rate and Dimension Changes in the Aldehyde/Pressure-Fixed Canine Carotid Artery

Cited by 10 publications

References 30 publications

Influence of graded changes in vasomotor tone on the carotid arterial mechanics in live spontaneously hypertensive rats

Influence of graded changes in vasomotor tone on the carotid arterial mechanics in live spontaneously hypertensive rats

Angiotensin converting enzyme inhibition prevents the increase in aortic collagen in rats.

Optimization of Vascular Casting for Three-Dimensional Fluorescence Cryo-Imaging of Collateral Vessels in the Ischemic Rat Hindlimb

Contact Info

Product

Resources

About