Involvement of nitric oxide and caveolins in the age-associated functional and structural changes in a heart under osmotic stress.

Previous work done in our laboratory showed that water restriction during 24 and 72h induced changes in cardiovascular NOS activity without altering NOS protein levels in young and adult animals. These findings indicate that the involvement of NO in the regulatory mechanisms during dehydration depends on the magnitude of the water restriction and on age. Our aim was to study whether a controlled water restriction of 1 month affects cardiac function, NO synthase (NOS) activity and NOS, and cav-1 and -3 protein levels in rats during aging. Male Sprague-Dawley rats aged 2 and 16 months were divided into 2 groups: (CR) control restriction (WR) water restriction. Measurements of arterial blood pressure, heart rate, oxidative stress, NOS activity and NOS/cav-1 and -3 protein levels were performed. Cardiac function was evaluated by echocardiography. The results showed that adult rats have greater ESV, EDV and SV than young rats with similar SBP. Decreased atria NOS activity was caused by a reduction in NOS protein levels. Adult animals showed increased cav-1. Water restriction decreased NOS activity in young and adult rats associated to an increased cav-1. TBARS levels increased in adult animals. Higher ventricular NOS activity in adulthood would be caused by a reduction in both cav. Water restriction reduced NOS activity and increased cav in both age groups. In conclusion, our results indicated that dehydration modifies cardiac NO system activity and its regulatory proteins cav in order to maintain physiological cardiac function. Functional alterations are induced by the aging process as well as hypovolemic state.

Embolismo por cristales de colesterol con síndrome de disfunción multiorgánica / Cholesterol crystal embolism with multiorgan dysfunction syndrome

Resumen: La embolia por cristales de colesterol es una enfermedad sistémica caracterizada por la oclusión de pequeñas arterias debido al desprendimiento de los mismos desde las placas de ateroma formadas en las paredes de arterias principales. Este caso clínico corresponde a un paciente masculino de 77 años de edad con factores de riesgo de enfermedad vascular que ingresó al servicio de urgencias por disnea y ortopnea. Se diagnosticó un cuadro clínico de insuficiencia cardiaca aguda y recibió tratamiento médico con buena respuesta. Se realizó una cinecoronariografía que evidenció severa ateroesclerosis coronaria con enfermedad de tres vasos, recibió tratamiento endovascular con colocación de endoprótesis vasculares. Luego de 20 días el paciente evolucionó con deposiciones melénicas, oligoanuria y claudicación intermitente progresiva en ambos miembros inferiores. Se observó obstrucción del flujo arterial en ambas arterias pedias por ecografía doppler; las biopsias de la piel de los pies revelaron signos vasculares correspondientes a depósitos de cristales de colesterol. Se interpretó enfermedad por embolia de cristales de colesterol secundario a las maniobras de cateterización previa, que provocaron alteraciones multiorgánicas isquémicas y persistentes. Resulta interesante este padecimiento porque es un proceso grave que demanda alto grado de sospecha clínica, el diagnóstico definitivo se establece mediante biopsia de las lesiones cutáneas, el pronóstico depende de la extensión de la enfermedad y en la actualidad no existe un tratamiento específico.

Abstract: The cholesterol crystal embolism is a systemic disease characterized by the occlusion of small arteries due these crystals, which come from the atheroma plaques of the walls of major arteries. This clinical case corresponds to a 77-year-old male patient with risk factors for cardiovascular disease who entered at the emergency service due dyspnea and orthopnea. In the Coronary Unit, a clinical status of acute heart failure was diagnosed, receiving medical treatment with good response. It was decided to perform a coronary angiography which showed a severe coronary atherosclerosis with 3-vessel compromised and endovascular treatment was performed with stent placement. After 20 days, the patient evolved with melenic depositions oligoanuria and progressive intermittent claudication in both lower limbs. Obstruction of arterial flow was observed in both pedia arteries by doppler ultrasound. Skin biopsies of lower limbs revealed vascular signs of deposits of cholesterol crystals. It was recognized as a cholesterol crystal disease secondary to previous medical catheterization procedures, causing ischemia and persistent alterations in the digestive and renal systems as well as in the skin of the lower limbs. This is an important affection because it is a serious process that demands a high level of clinical suspicion, the definitive diagnosis is established through the biopsy of the cutaneous lesions and the prognosis depends on the extension of the disease. Nowadays, there is no specific medical treatment of this disease.