Perfusable vascular tree like construction in 3D cell-dense tissues using artificial vascular bed

INTRODUCTIONWe have used an experimental model which allows the evaluation of the qualitative differences in the retinal vascular pattern by means of the labeling of the retine vascular tree with radish peroxidase (HRP) in estreptozotocin-diabetic rats. The aim of the study was to evaluate the effect of ASA and DIP + ASA on the vessels platelet behaviour of said retine pattern in a group of rats in t-hich the diabetes had 3 months of evolution.PROCEDURE22 Wistar male rats were divided into A groups; 1) control group, 2) diabetic rats without antiaggregant, 3) dietetic rats treated with 6 mg/day ASA p.o., 4) diabetic rats treated with 6 mg/day ASA +12 mg/day DIP p.o. For inducing diabetes 30 mg/Kg of i.v. estreptozotocine were administered. The animals were considered “diabetic” when glucemia was over 200 mg/100 ml. After 3 months of treatment with 4IU insuline and ASA, or ASA + DIP, the animals were sacrified. Samples of blood and rings of descending aorta were extracted. Platelet aggregation in IJB in front of 1 μg/ml of collagen and the prostacycline-like activity of the aorta ring were evaluated. The configuration of the retine vascular tree labeled with HRP was observed.RESULTS AND CONCLUSIONSMaximal aggregation intensity: 11.1 Ω in the control group,10.9Ω in the diabetic non-treated group, 4.8Ω in rats receiving ASA and 4.6Ω in rats treated with DIP + ASA. The incUbation during 10 min. of aorta rings in blood samples produced 38.7% inhibition in the control group, 12.8% in the non treated-diabetic group 0% in the ASA group and 49.3% in the group treated with DIP + ASA.The qualitative changes in the diabetic rats retinal vascular network non treated with antiaggregants showed a scarce visibility of capillars as well as large zones of tortuous vessels. The rats treated with ASA showed a continuous vascular bed and less tortuous vessels than the ones in the non treated group but the vascular diameters were smaller than the ones observed in non-diabetic rats; the rats treated with DIP + ASA showed a continuous vascular bed, scarce tortuous vessels and vascular diameters similar to the ones found in non-diabetic rats. Mortality rates: 0% in the control group, 50% in the non-treated diabetic group, 16% in the ASA group and 0% in the DIP + ASA group. The administration of DIP + ASA normalized the prostacycline-like activity and the retinal vascular pattern in estreptozotocin-diabetic rats.

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Early Changes in Vascular Dynamics in Relation to Twin-Twin Transfusion Syndrome

Twin Research ◽

10.1375/twin.4.5.371 ◽

2001 ◽

Vol 4 (5) ◽

pp. 371-377 ◽

Cited By ~ 4

Author(s):

Helena M. Gardiner

Keyword(s):

Fetal Programming ◽

Laser Photocoagulation ◽

Pulse Wave ◽

Twin Pair ◽

Disease Process ◽

Vascular Tree ◽

Control Groups ◽

Arterial Distensibility ◽

Vascular Bed ◽

Increased Risk

AbstractAclearer understanding of the early determinants of normal and abnormal vascular development is pivotal in order to identify those at increased risk of later vascular disease, and perhaps to prevent it by early intervention. Measurement of pulse wave velocity(PWV) has been used in the postnatal evaluation of the monochorionic(MC) twins. They are genetically identical and those with twin-twin transfusion syndrome(TTTS) provide an ideal natural model in whom to study the influence of differing haemodynamic stresses on the developing vascular tree. We investigated firstly whether surviving twin pairs with TTTS have altered arterial distensibility in childhood by comparing PWV in the radial arteries of surviving MC twin pairs with TTTS and in two control groups, one cohort of MC twins without TTTS and another dichorionic group (DC) Secondly, we tested a cohort of TTTS twin pair survivors treated with laser photocoagulation. The co-twin pairs in the group managed palliatively with amnioreduction showed increased PWV in the donor and reduced PWV in the recipient twins. This was neither seen in the laser-treated, nor in the control groups. Our studies suggest that a period of haemodynamic imbalance gives rise to changes in a muscular conduit artery that persist at least into infancy and it seems that by correcting the abnormal haemodynamics relatively soon after the disease process had begun, the alterations in elasticity are prevented. These studies are the first to demonstrate fetal programming of the vascular bed in humans, and prevention or reversal of this programming by an intervention in mid-gestation.

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Vascular Diseases are Essentially a Matter of Haemorheology and of Haemostaseology

10.1055/s-0039-1687361 ◽

1979 ◽

Author(s):

H. Hess

Keyword(s):

Shear Rate ◽

Abdominal Aorta ◽

Vascular Diseases ◽

Vascular Tree ◽

Local Conditions ◽

Small Arteries ◽

Vascular Bed ◽

Plasmatic Coagulation ◽

Adhesion Of Platelets ◽

Terminal Vascular Bed

Vascular diseases have, in different segments of the vascular tree, a different morphology. There is an arteriosclerosis but not an obliterating arteriosclerosis of thoracic and of proximal abdominal aorta. The obliterating arteriosclerosis exists in the branches and in the continuation of these vessels up to the small arteries. Changes similar to arteriosclerosis don't exist either in the terminal vascular bed nor in veins. The material and structure of obliterations is differently composed in different segments of vessels. All those differences are essentially caused by the different local conditions of haemorheology and haemostaseology. A very important point is - the aggregation and adhesion of platelets is posi tively correlated with the shear rate, whereas the activation of the plasmatic coagulation and the development of aggregates of erythrocytes is negatively correlated with the shear rate. The consequences of this for the different vascular segments are fully discussed in the lecture.

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