The effect of ethnic factor on cephalic index in 17-20 years old females of north of Iran / Efectos Beneficiosos del Bloqueador AT1 de la Angiotensina II en la Remodelación Cardiovascular Adversa Causada por el Bloqueo de la Síntesis de Óxido Nítrico

RESUMEN

El índice cefálico y forma de la cabeza son afectados por factores geográficos, género, edad, raza y grupos étnicos. Este estudio determina el índice cefálico y la forma de la cabeza en mujeres entre 17 y 20 años de edad en Gorgan, Norte de Irán. El estudio fue realizado en 410 mujeres normales de17 a 20 años de edad (grupo Turco n=203, grupo Fars n=207) del Norte de Irán, a través de cefalometría clásica. La media y DS del índice cefálico fue 85 + - 4.5 y 82.8 + - 3.6 en nativos de los grupos Fars y Turcos, respectivamente. Tipos dominantes y raros de la forma de la cabeza en el grupo Fars fueron hiperbraquicefálico (53.6 por ciento) y dolicocefálico (15 por ciento), y en el grupo Turco fueron braquicefálico (58.1 por ciento) y dolicocefálico (0.05 por ciento), respectivamente. Estos resultados y el de otros estudios realizados en el mundo, permiten concluir la influencia que tienen los factores étnicos en las dimensiones de la cabeza.

ABSTRACT

We studied with morphological tools the effects of different doses of Losartan upon the cardiovascular remodeling in nitric oxide deficient rats. At 15 weeks of age, thirty Wistar rats were separated in six groups control (C), L-NAME (LN), and four groups were LN was given plus Losartan at different doses (1, 5, 20 and 40 mg/kg/day). The L-NAME was given for 9 weeks, the Losartan administration starting on the 2nd week of experiment. We studied the heart, thoracic aorta and superior mesenteric artery with light microscopy and stereology. The blood pressure (BP) increased since the first week of L-NAME administration, the Losartan treatment at doses of 20 and 40 mg/kg/day was efficient to reduce BP after the 7th week of treatment. The cardiac adverse remodeling in the LN group was characterized by intense interstitial fibrosis, impairment of the myocardial microvascularization, cardiomyocyte hypertrophy and consequent loss of cardiomyocytes. The aortic wall structure (density per area of smooth muscle cell nuclei and surface density of lamellae), and the superior mesenteric artery media/lumen ratio were also strongly affected by L-NAME administration. Only in the dose equal or higher than 20 mg/kg/day Losartan showed beneficial effects treating these alterations. In conclusion, both the heart and the arterial wall of NO deficient rats suffer a marked adverse remodeling process that is efficiently treated by a dose-dependent Losartan administration. The efficiency of Losartan treatment in this model of NO synthesis blockade correlates with the hypotensor effect of the drug mainly in the high dose treatment.