Topic:Angiogenesis
Angiogenesis in horses refers to the physiological process through which new blood vessels form from pre-existing vessels, a critical component in tissue growth, repair, and regeneration. This process is key in equine health for wound healing, reproductive functions, and the response to various injuries and diseases. Angiogenesis is regulated by a balance of pro-angiogenic factors, such as vascular endothelial growth factor (VEGF), and anti-angiogenic factors, which orchestrate the formation of new vasculature. In horses, dysregulation of angiogenesis can contribute to pathological conditions, including laminitis and certain types of cancer. This page compiles peer-reviewed research studies and scholarly articles that explore the molecular pathways, regulatory mechanisms, and clinical implications of angiogenesis in equine medicine.
Disuse inhibition of newly functional coronary collateral circulation in ponies. We evaluated the loss of coronary collateral function in the absence of stimulation (disuse inhibition) by doubling the interval between successive left anterior descending coronary artery (LAD) occlusions in ponies in which collateral function initially had been enhanced by 2-min occlusions at 30-min intervals. Before collateralization, occlusion caused segment systolic shortening, velocity of shortening, and stroke work index in the LAD-dependent left ventricular apex to decrease, whereas heart rate and left ventricular end-diastolic pressure increased. After 476 +/- 102 occlusions, segment ...
Identification of a free skin flap from the region vascularized by the deep circumflex iliac artery of horses. Areas of skin vascularized by large axial vessels potentially suitable for microvascular anastomosis were investigated in 10 horse cadavers. Eleven such areas were dissected, and the skin over the flank region vascularized by the deep circumflex iliac artery was most suitable. The anatomy of this area was further defined, using angiography and latex injection studies on 10 cadavers.
The pathogenesis and significance of pre-iridal fibrovascular membrane in domestic animals. Histologic examination was made of 1,419 globes from domestic animals (964 dogs, 374 cats, 41 horses, and 40 cattle) with ocular disease; pre-iridal membranes (rubeosis iridis) were found in 98. The membranes originated as endothelial budding from the anterior iridal stroma and seemed to mature into fibrous or fibrovascular membranes that were often followed by hyphema or, occasionally, glaucoma. Pre-existent disease in the 98 affected globes included chronic endophthalmitis (27/98), chronic glaucoma (24/98), anterior uveal melanoma (15/98), ciliary body adenoma (14/98), neoplasms metastatic t...
Lameness in a mare with signs of arteriovenous fistula. A 5-year-old mare was evaluated for lameness and swelling of the right forelimb. Clinical findings, including peripheral edema, venous pulsation, palpable thrill in the cephalic vein, disparate arteriovenous oxygen tension differences between the left and right forelimbs, and Branham sign, were suggestive of arteriovenous fistula. Failure to identify the fistula by angiography was attributed to closure of the shunt during anesthesia. Surgical exploration of the affected limb to identify the shunt also was unsuccessful.
Exercise-induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. VIII. Conclusions and implications. This paper reviews a series of clinical, post mortem and imaging studies on exercise-induced pulmonary haemorrhage (EIPH) performed on 26 Thoroughbred racehorses. Post mortem techniques included routine gross, subgross and histological examination; coloured latex perfusions of pulmonary and bronchial circulations; and microradiography and computerised tomography scans of lungs with contrast injected vasculature. The major lesions were multiple, separate and coalescing foci of moderately proliferative small airway disease accompanied by intense neovascularisation of the bronchial circulation. A...
Cardiopathology of sudden cardiac death in the race horse. Twenty thoroughbred race horses were selected for postmortem cardiopathological study of sudden cardiac death; ten of the twenty horses died suddenly. In order to define accurately the morphological changes observed in these ten hearts, ten other thoroughbred race horses considered to have normal hearts were selected as a control group and studied by postmortem coronary angiography. Of the ten horses that died suddenly, eight were witnessed to have died either during or shortly after training or racing. The death was instantaneous except in one horse, which showed ventricular tachycardia and d...
Carotid and cerebral angiography in the horse. Carotid and cerebral angiography has been found to be a relatively simple technique to carry out in the horse. At most it involves a cutdown approach to the carotid artery, followed by catheterisation of the artery and selective catheterisation, if necessary, of one of its three branches. The technique can be carried out with standard equipment normally available within equine hospital facilities. The authors have employed angiography as a routine aid to diagnosis over the past nine years, without encountering any serious complications or adverse reactions. Carotid angiography has been especia...
Ventricular septal defects in the horse. Clinical, echocardiographic, and right-side cardiac catheterization data were collected in 6 horses with ventricular septal defects. The defects were confirmed by necropsy in 5 horses. On echocardiography, the cardiac dimensions were normal in 3 horses and enlarged in 2 others. A step-up in partial oxygen pressure between right atrium and right ventricle suggested a left-to-right shunt in 3 of the 4 horses catheterized. In 1 foal, a small defect without PO2 step-up was documented by angiocardiography. The oxymetry and pressure data were compared with previous cases from the reviewed literature...
Microangiographic studies of metaphyseal vessels in young foals. Selective perfusion and microangiographic examination of the radius and metacarpus of 30 foals were performed. Vessels of extraosseous origin supplying the peripheral part of the metaphysis were not demonstrated in young foals, but became more obvious in older animals. The development of this vessel system coincided with the reduction of transphyseal vessels from the epiphysis crossing the growth plate.
Navicular disease in the horse. A microangiographic investigation. Microangiographical investigations of the navicular bone in horses with navicular disease show, compared to similar investigations of normal navicular bones, that, in general, the vascular pattern is preserved but the vessels are dilated with "pooling" of the contrast medium subchondrally under facies flexoria. Similar changes may be observed in cases of human arthrosis. The present investigation therefore supports the view that navicular disease is a disease which resembles arthrosis.
Effect of exercise, phenylbutazone, and furosemide on the plasma renin activity and angiotensin I in horses. Circulating concentrations of angiotensin I and plasma renin activity (PRA) were determined in 45 Thoroughbreds before prerace medication (at rest), 1 to 1 1/2 hours before racing but after prerace medication (prerace), within 15 minutes after racing (immediately postrace), and between 1 to 2 hours after racing. Angiotensin I was measured by radioimmunoassay, and PRA was determined by the rate of generation of angiotensin I in plasma incubated at 37 C. Irrespective of prerace medication, there was a marked increase in angiotensin I (0.478 +/- 0.034 to 0.848 +/- 0.051 ng/ml) and PRA (0.191 +/- ...
[Architectonics of the blood vessels in the wall of the allantoamnion of the mare]. Alantoamnion vascularization was studied on clarified preparations from three mares in advanced pregnancy. Two large blood vessels (artery and vein) beginning from the umbilical vessels were found in the alantoamnion wall. Numerous anastomoses were observed at the passage between the arterial and the vein section. The large arteries had a thick, jely-like vascular wall and snake-like folded lumen. In separate sections of the alantoamnion wall a well developed capillary net was observed consisting of individual particles, polygonal in shape. Vast avascular zones surrounded by numerous vascular ...
An experimental study of autologous digital tendon transplants in the horse. Four autologous tendon grafting techniques, bipedicle, pedicle and free grafts of the deep digital flexor tendon and free grafts from the lateral digital extensor tendon were described. The vascularization and remodelling of the transplant and the reactions in the donor, as well as the recipient tendon, were studied by means of microangiographic and histochemical methods. The results indicated that regardless of the technique used the grafts were revascularized and replaced by a highly orientated and organized tendon. The use of free grafts may therefore be worthwhile in treatment of severe te...
Angiography of equine metacarpus and phalanges: alterations with medial palmar artery and medial palmar digital artery ligation. Vascular supply of the equine forelimb was partially disrupted by ligation of the medial palmar and medial palmar digital arteries. Vascular architecture was evaluated before and after ligation by angiography. It was apparent from the present study that existing collaterals or newly formed collaterals, or both, were sufficient to maintain limb viability.
Angiographic appearance of the normal equine foot and alterations in chronic laminitis. The angiographic appearance of the normal equine foot was compared with the appearance of equine feet affected with chronic laminitis. The normal foot was characterized by complete filling of the terminal arch, 8 to 10 main branches between 0.1 and 0.2 cm in diameter, a symmetrical netlike vascular pattern in the corium of the hoof, and numerous fine vessels in the corium of the coronary band. The feet affected with chronic laminitis were characterized by poor filling of the terminal arch, larger and less numerous primary branches, an irregular vascular pattern in the corium of the hoof, areas...