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At least 19 recordsLinked to original sources
PubMed1979

Vertical gradient in regional vascular resistance and pre to post capillary resistance ratios in the dog lung.

The ratios of pre-capillary (Ra) and post-capillary (Rv) resistances to total vascular resistance (RT) were measured at different vertical distances in the lungs of supine dogs. Capillary pressures were estimated as the algebraic sum of the alveolar absorption pressure for Tyrode's solution and the plasma colloid osmotic pressure. Segmental resistance fractions (Ra/RT, Rv/RT) were calculated using the pressure drops between arterial, capillary, and venous pressures at each vertical distance within the lung. In a second group of animals, total vascular resistance was calculated at each lung level using regional blood flow as measured by radiolabelled microspheres and the corresponding regional vascular pressures. The total vascular resistance was lowest in Zone III portions of the lung, but Ra/RT and Rv/RT were constant throughout this zone (n = 22) averaging .63 +/- .02 (SEM) and .37 +/- .02 (SEM, respectively, resulting in Ra/Rv of 1.70). Total vascular resistance increased markedly in Zone II portions of the lung, but the relative contribution of Ra/RT decreased from .62 +/- .07 (SEM) to .45 +/- .05 (SEM). Thus Ra/Rv decreased from 1.70 to .82 in Zone II. The absolute values of pre- and post-capillary resistances were lowest in Zone III but post-capillary resistance increased to a greater degree than pre-capillary resistance up Zone II.

Animals↗
PubMed1975

Capillary resistance and back pain.

A rapid clinical and epidemiological method of grading Capillary Resistance (CR) based on the appearance of petechiae following negative pressure on the skin of the forearm is described, and the results of testing 469 postmen aged 22 to 63 years are given. CR is shown to be increased in men who have had back pain within 24 hours of testing and no difference was found between men who had had back pain in the past and those who denied ever having had back pain. A separate series of 35 post-laminectomy patients examined at least 10 months after operation and who were shown to have disc disease at operation and/or on myelogram were found to have low CR. This work suggests that the changes involved in disc disease are not limited solely to the discs, but may involve collagen/elastic tissue or ground substance elsewhere as for example in this case when detectable in a test on the forearm. Secondly, it is suggested that CR grading could be a helpful discriminating test for 'disc disease' among those presenting with back pain of undetermined diagnosis.

Adult↗
PubMed1978

Reduced capillary resistance in allergic patients.

Fifty four of 67 allergic children (81%) had a pathologically reduced capillary resistance (CR) of less than 16 cm Hg. Five of the 13 allergic children with normal CR were treated with corticosteroids. Prednisone improved CR in on patient for at least 24 h, and this was reflected by improvement of hemorrhagic parameters such as bleeding intensity, bleeding pattern and blood loss. There was no correlation between CR and IgE levels. 90% of the symptomatic relatives of allergic children had a reduced CR, but only 44% of asymptomatic relatives. CR presents a simple additional tool for diagnosing allergy and might give hints to the carrier state of allergy.

Adolescent↗
PubMed1975

Effects of some phlogistics on the capillary resistance of the rabbit conjunctiva.

Applying certain phlogistics (10% ol. sinapis, tinct. capsici, Dionin) and 1.5% histamine solution to the conjunctival sac of rabbits led to a mathematically significant decrease in conjunctival capillary resistance in every experimental animal. The effect occurred 20 to 30 min after application of the various pharmacons.

Animals↗
PubMed1975

Studies on small intestinal obstruction. II. Blood flow, vascular resistance, capillary filtration, and oxygen consumption in denervated small bowel after obstruction.

Intestinal circulation was studied during in vitro perfusion of denervated small intestine of the cat shortly after release of an in vivo small-bowel obstruction. Blood flow, vascular resistance, capillary filtration, and oxygen consumption were determined. No significant differences were demonstrated between obstructed and non-obstructed intestines. The presently studied facets of small-bowel microcirculation thus exhibit a virtually normal function 30 minutes after decompression of a bowel obstruction. The pertinent literature affords evidence that a distension impairs bowel viability; it would seem that this impairment is rapidly ameliorated following decompression of the bowel.

Animals↗
PubMed1975

The influence of rheological and collapse factors on pre- and post-capillary flow resistances in the skeletal muscle vascular bed of the cat.

The importance of passive-elastic changes of vascular dimensions and shifts in regional effective viscosity for the pre-/postcapillary resistance ratio (RA/RV), and hence mean capillary pressure (PC), was analyzed in cat calf muscles. Reductions of mean venous distending pressure below 6-8 mm Hg induced marked RV increases due to escalating venous collapse. This mechanism tends to delimit the PC reductions and rate of transcapillary fluid absorption during intense precapillary vasoconstriction. Comparisons of RA/RV for erythrocyte suspensions (Hct 40-50) and cellfree perfusates at identical vascular dimensions showed that RA/RV was considerably higher, and PC correspondingly lower, for the erythrocyte suspension except at very low flows. This RA/RV difference increased with increasing flow and at very high flows PC was about 10 mm Hg lower during perfusion with the erythrocyte suspension. These findings apparently diverge from the known influence of the tube radius and linear flow velocity on effective in vitro viscosity of blood. Since distal precapillary and proximal capillary sections, both having smaller diameters than the erythrocytes, are located upstream to the point of filtration-absorption equilibrium, they contribute in this respect to RA. It is therefore suggested that the increasing RA/RV with erythrocyte perfusion, particularly at higher flows, is not due to genuine viscosity factors but to friction losses when cells in "bolus flow" are squeezed through the narrowest precapillary sections.

Animals↗
PubMed1975

Pharmacodynamic study of the capillaries of normal and allergic (atopic) subjects.

Using the capillary resistance test as a method to study the cutaneous microvessels, a number of capillary active agents were investigated by applying them percutaneously in hydrophylic ointment base to manifestly allergic and definitely non-allergic volunteers. While the catecholamines and heparin increased capillary resistance in both allergic and non-allergic groups, metacholine, serotonin, the somatotropic hormone and nitroglycerin either did not change or decreased capillary resistance in the normal group and invariably increased it in the members of the allergic group. The effects of catecholamines were, completely or partially, blocked in the normal group by pretreatment of the skin with dibenzyline or propranolol. In the members of the allergic group, blockade was often weak or absent indicating some derangement in the adrenergic receptors. The significance of the findings is discussed.

Adolescent↗
PubMed1979

[Determination of capillary lesions during diagnosis by means of the tourniquet test of microangiopathies in diabetes mellitus].

Decreased capillary resistance is documented by a pathologic tourniquet test (Rumpel-Leede), which demonstrates the existance of microangiopathy in diabetics. Thanks to its simple and rapid execution the tourniquet test is suitable for early diagnostic assessment of the situation in the microcirculation. The longer the patients have had diabetes, the more frequently is the tourniquet test pathological. There is also a direct correlation between the type of therapy (as an index of the severity of the disease) and the accumulation of pathologic results in measurement of capillary resistance. In diabetics with hypertension, capillary resistance is always decreased to a pathologic degree.

Capillary Resistance↗
PubMed1979

[Simple diagnosis of diabetic microangiopathy by means of the tourniquet test].

The pathological results of the tourniquet test after Rumpel-Leede by the establishment of a decreased capillary resistance refers to the presence of a microangiopathy in diabetics and by its rapid and simple performance is suitable for the preliminary diagnostics, in order to judge the conditions of microcirculation. The longer the diabetes exists the oftener a pathological result is found in the tourniquet test. The form of therapy as parameter for the severity of the disease shows a direct relation to the accumulation of pathological findings of capillary resistance. In diabetic hypertensive patients regularly a pathologically decreased capillary resistance is to be found.

Adolescent↗
PubMed1976

Effects of noradrenaline on consecutive vascular segments at low or normal calcium concentrations in control and spontaneously hypertensive rats.

1. An 'isogravimetric' technique, plus measurement of pressure in a small artery, was used to investigate the responses of upstream and downstream precapillary and postcapillary resistance vessels in the hindquarters of spontaneously hypertensive rats (SHR) and normal control rats perfused at constant flow. 2. Dose-response curves to noradrenaline were constructed under conditions of low or normal calcium. 3. In both control rats and SHR the dependence on external calcium during contraction increased peripherally, with the smaller pre- and post-capillary resistance vessels being most dependent and larger arteries least dependent. 4. There may be differences between SHR and control rats in regard to the handling of calcium, particularly in the small pre- and post-capillary resistance vessels.

Animals↗
PubMed1975

Effect of calcium bodesilate (doxium) on circulatory disorders of the retina with special emphasis on diabetic retinopathy.

The authors examined the effect of calcium dobesilate (Doxium ¿) on 85 subjects with diabetic retinopathy, occlusion of the central vein of the retina and other retinopathies of vascular origin. Capillary resistance measured on the skin and conjunctiva showed, as compared with 100 healthy subjects, a significant decrease. The efficacy of long-term treatment with Doxium was highly significant in restoring CR to normal. Visual acuity improved in 45.8% of simple DR cases, and became stabilized in 27.5% of cases with malignant DR. Hyperpermeability of retinal vessels decreased in 60% of simple DR cases. It is pointed out that glaucoma did not develop in cases of venous occlusion and the diagnostic value of capillary resistance measurement in diabetes. As a highly effective vasoprotective drug, Doxium¿ is the treatment of choice in all retinopathies of vascular etiology.

Adolescent↗
PubMed1976

Studies on Vaccinium myrtillus anthocyanosides. II. Aspects of anthocyanins pharmacokinetics in the rat.

Vaccinium myrtillus anthocyanins adminstered by i.v. or i.p. route to the rat undergo a rapid body distribution and in part also are easily eliminated such as to fit a three-compartments pharmacokinetic model. The anthocyanins elimination occurs mostly through urine and bile. The slight difference between the amount of anthocyanins eliminated after i.v. and after i.p. application shows a modest liver extracion of these substances. Vaccinium myrtillus anthocyanins possess a greater affinity for some tissues, namely kidneys and skin rather than for plasma. This fact could explain the long-lasting activity of anthocyanins on capillary resistance which is still elevated when plasma levels of these substances are no more detectable.

Animals↗