ABSTRACT
A doença da microcirculação coronariana pode ser encontrada em vários tipos de cardiomiopatia. A cardiomiopatia dilatada idiopática, a cardiomiopatia hipertrófica, a cardiomiopatia da hipertensão arterial sistêmica e a cardiomiopatia da doença de Chagas são as que mais freqüentemente se associam à doença da microcirculação coronariana. Na maioria das vezes, ocorre estreitamenrto luminal secundário à proliferação das camadas média e íntima, visualizadas à microscopia óptica. Com o emprego da microscopia eletrônica, pode-se observar espessamento da membrana basal capilar. O mecanismo patogenético da doença da microcirculação coronariana não é conhecido. É possível que anticorpos antiendotélio, como na cardiomiopatia dilatada idiopática, assim como hipertrofia e alterações na estrutura da organização miocítica determinadas geneticamente, como na cardiomiopatia hipertrófica, sejam determinantes patogenéticos. Presente, a doença da microcirculação coronariana pode levar à hipoxia miocárdica crônica, culminando no remodelamento ventricular e no aparecimento da cardiomiopatia.
Subject(s)
Humans , Coronary Artery Disease/etiology , Microcirculation/anatomy & histology , Microcirculation/physiopathology , Cardiomyopathies , Cardiomyopathy, Dilated , Cardiomyopathy, Hypertrophic , Hypertension , Chagas CardiomyopathyABSTRACT
OBJECTIVE: To study the influence of sex on the responses of microvessels to vasoactive agents in experimental diabetes. MATERIALS: Diabetes was induced by alloxan (40 mg/kg, iv) in male and female Wistar rats (8-10-week-old). METHODS: Using an image splitter television microscope, mesenteric arteriolar and venular diameter changes induced by topically applied vasoactive agents (histamine, bradykinin, platelet activating factor-PAF, acetylcholine, sodium nitroprusside, noradrenaline and angiotensin II) were examined. RESULTS: Whereas the vasoconstrictor response to noradrenaline was equivalent in normal and diabetic animals, either female or male rats, an increased vasoconstrictor response to angiotensin II was observed in male but not in female diabetic rats in comparison with respective controls. Similarly to that observed in males, the dilator response of microvessels to topically applied bradykinin, histamine and PAF was impaired in female diabetic rats. Whereas reversal of the impaired responses to these agents was obtained by acute treatment of diabetic animals with insulin the altered responses to angiotensin II observed in male diabetic rats were not corrected. Differently from that observed in males, impaired response of microvessels to acetylcholine but not to sodium nitroprusside was observed in female diestrous diabetic rats; acute insulin treatment corrected it. CONCLUSIONS: We conclude that not all the alterations of the microvascular reactivity and the correction by insulin are gender dependent in diabetes.
Subject(s)
Diabetes Mellitus, Experimental/physiopathology , Acetylcholine/pharmacology , Angiotensin II/pharmacology , Animals , Body Weight/drug effects , Bradykinin/pharmacology , Estrous Cycle/drug effects , Female , Histamine/pharmacology , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Male , Microcirculation/anatomy & histology , Microcirculation/drug effects , Microcirculation/physiopathology , Nitroprusside/pharmacology , Norepinephrine/pharmacology , Organ Size/drug effects , Platelet Activating Factor/pharmacology , Rats , Rats, Wistar , Sex Characteristics , Uterus/drug effects , Vasoconstrictor Agents/pharmacology , Vasodilator Agents/pharmacologyABSTRACT
Os autores analisam os principais métodos de investigação morfofuncional da microcirculação da pele em diabéticos, tanto na literatura médica recente quanto na própria experiência em videocapilaroscopia subungueal, no ãmbìto dos atuais avanços do conhecimento sobre a fisiopatologia da microangiopatia diabética. Na videocapilaroscopia basal, feita na região periungueal das mãos, ressaltam a importància e a significativa prevalência das alterações morfológicas como edema, microaneurismas, tortuosidade e dilatação do segmento venoso capilar, tanto em indivíduos diabéticos quanto em parentes de 1§ grau com testes de tolerância à glicose normais. Mostram o valor dos estudos das respostas dinàmicas da microcirculação à isquemia e a estímulos farmacológicos, observadas, sobretudo, por medidas de velocidade e/ou fluxo sangüíneo na videocapilaroscopia e dopplerfluxometria a laser, que, na maioria dos trabalhos, estavam alteradas em fases muito precoces da doença, por vasodilatação inadequada. São descritas as medidas do diãmetro e da área do segmento transverso capilar em videocapilaroscopia que podem ser úteis como parâmetros-respostas ao teste de isquemia reperfusão. Os autores discutem as bases da fisiopatologia que justificam as alterações observadas na videocapilaroscopia tanto basal como dinâmica.
Subject(s)
Humans , Diabetic Angiopathies/physiopathology , Skin , Microscopic Angioscopy/methods , Microcirculation/anatomy & histologyABSTRACT
Although vasomotion has been considered a feature of the microvascular bed under physiological conditions, it has also been observed following hypotension in several tissues. In this work, 158 mesenteric microvessels of 36 rats were investigated quantitatively in normovolemic and hemorrhaged animals, focussing on diameter changes, particularly vasomotion incidence and characteristics. The femoral arteries of Wistar rats (body weight BW = 188 +/- 23 g, mean +/- SD) anesthetized with pentobarbital were cannulated for arterial pressure (AP) monitoring and blood withdrawal. The protocol consisted of 15 min control and 30 min of hemorrhagic hypotension (AP = 52 +/- 5 mmHg, hemorrhaged vol. = 17 +/- 4 ml/kg BW). During control normovolemic conditions, analysis of mesenteric microcirculation using intravital videomicroscopy revealed neither arteriolar nor venular vasomotion. During hemorrhagic hypotension (HH) microvascular blood flow reduced to 25% of control. While venules did not show diameter changes during HH, arterioles contracted to 85 +/- 20% of control and arteriolar vasomotion appeared in 42% of the animals and 27% of the arterioles. The amplitude of arteriolar diameter change during HH relative to mean diameter and to control diameter averaged 65 +/- 24% (range: 32-129%) and 41 +/- 10% (range: 25-62%), respectively. Vasomotion analysis showed two major frequency components: 1.7 +/- 0.8 and 7.0 +/- 5.2 cycles/min. Arterioles showing vasomotion had a mean control diameter larger than the remaining arterioles and showed the largest constriction during HH. We conclude that hemorrhagic hypotension does not change venular diameter but induces arteriolar constriction and vasomotion in rat mesentery. This activity is expressed as slow waves with high amplitude and fast waves with low amplitude, and is dependent on vessel size.
Subject(s)
Hemorrhage/physiopathology , Hypotension/physiopathology , Splanchnic Circulation/physiology , Vasomotor System/physiopathology , Animals , Blood Pressure/physiology , Male , Microcirculation/anatomy & histology , Microcirculation/physiopathology , Rats , Rats, WistarABSTRACT
La descripción del triángulo opto - carotídeo (TOC) es muy escasa en la literatura neuroquirúrgica, a pesar de ser un área importante en el manejo de patología vascular variada y frecuente. Con la introducción de nuevas tecnologías imagenológicas y la evolución en las técnicas microquirúrgicas y en cirugía de base de cráneo, es sumamente importante el conocimiento y definición de las áreas anatómicas relevantes en cirugía microvascular, incluyendo su descripción morfométrica. El TOC es un área anatómica que debe de ser abordada durante un importante número de procedimientos neurovasculares, así como para patologías no vasculares y que involucran la región.
Subject(s)
Microcirculation/anatomy & histology , Microsurgery , Optic Nerve/anatomy & histology , Optic Chiasm/anatomy & histology , Carotid Sinus/anatomy & histology , Vascular Surgical Procedures/methodsABSTRACT
La detección temprana de síndromes esclerodermoformes es de gran relevancia para el pronóstico del paciente. Nuestro objetivo es determinar la utilidad de la capilaroscopía periungueal en el diagnóstico diferencial entre Raynaud primario y secundario a síndromes esclerodermiformes. Se estudian pacientes con Raynaud primario (21), Raynaud secundario a síndromes esclerodermia sistémica (57) y Raynaud secundario a síndromes de superposición con esclerodermia (19). El grupo control de sujetos sin Raynaud estudiados fue de 40 personas. Todos los grupos fueron estudiados por capilaroscopía periungueal de dedos de ambas manos por medio de microscopio esteroscópico de 40 aumentos. La especificidad del método para detección de patrón SD (esclerodermiforme) fue de 100 por ciento y la sensibilidad asciende 82,5 por ciento para esclerodermia sistémica y 57 por ciento para síndromes de superposición (AU)
Subject(s)
Humans , Raynaud Disease/diagnosis , Nails/blood supply , Diagnostic Techniques and Procedures , Microcirculation/anatomy & histology , Raynaud Disease/physiopathology , Scleroderma, Systemic/classification , Scleroderma, Systemic/complications , Case-Control Studies , Capillaries/pathologyABSTRACT
La detección temprana de síndromes esclerodermoformes es de gran relevancia para el pronóstico del paciente. Nuestro objetivo es determinar la utilidad de la capilaroscopía periungueal en el diagnóstico diferencial entre Raynaud primario y secundario a síndromes esclerodermiformes. Se estudian pacientes con Raynaud primario (21), Raynaud secundario a síndromes esclerodermia sistémica (57) y Raynaud secundario a síndromes de superposición con esclerodermia (19). El grupo control de sujetos sin Raynaud estudiados fue de 40 personas. Todos los grupos fueron estudiados por capilaroscopía periungueal de dedos de ambas manos por medio de microscopio esteroscópico de 40 aumentos. La especificidad del método para detección de patrón SD (esclerodermiforme) fue de 100 por ciento y la sensibilidad asciende 82,5 por ciento para esclerodermia sistémica y 57 por ciento para síndromes de superposición
Subject(s)
Humans , Diagnostic Techniques and Procedures , Microcirculation/anatomy & histology , Raynaud Disease/diagnosis , Nails/blood supply , Capillaries/pathology , Case-Control Studies , Scleroderma, Systemic/classification , Scleroderma, Systemic/complications , Raynaud Disease/physiopathologySubject(s)
Microscopic Angioscopy/history , Microscopic Angioscopy/methods , Microscopic Angioscopy , Raynaud Disease/classification , Raynaud Disease/diagnosis , Raynaud Disease/epidemiology , Raynaud Disease/physiopathology , Microcirculation/anatomy & histology , Blood Vessels , Capillaries/abnormalities , Scleroderma, Systemic/diagnosis , Dermatomyositis , Psoriasis , Arthritis, Rheumatoid , Neovascularization, Physiologic , Rheology , Arthritis, Psoriatic , Lupus Erythematosus, Cutaneous , Sjogren's SyndromeSubject(s)
Microscopic Angioscopy , Microscopic Angioscopy/history , Microscopic Angioscopy/methods , Arthritis, Psoriatic , Arthritis, Rheumatoid , Capillaries/abnormalities , Dermatomyositis , Raynaud Disease/classification , Raynaud Disease/diagnosis , Raynaud Disease/epidemiology , Raynaud Disease/physiopathology , Scleroderma, Systemic/diagnosis , Lupus Erythematosus, Cutaneous , Microcirculation/anatomy & histology , Neovascularization, Physiologic , Psoriasis , Rheology , Sjogren's Syndrome , Blood VesselsABSTRACT
Se realizó un estudio de la microcirculación del tronco cerebral, realizado con perfusión de una solución de sulfato de bario coloidal al10 por ciento en el sistema arterial vértebro-basilar en cadáveres humanos y microangiogramas de secciones transversales del tronco cerebral perfundido. El patrón vascular intrínseco del tronco cerebral, se puede dividir en tres zonas constantes en todas sus partes, que son : la mediana, la paramediana y la dorsolateral. Esta técnica brinda una información importante sobre los mecanismos fisiopatológicos de los infartos en esta parte del encéfalo (AU)