Ultrastructural study of the kidney subjected to warm ischemia and perfused with inosine.

OBJECTIVES: Renal ischemia, depending on its duration, results in organ function loss to a greater or lesser extent, due to the depletion of the energy cells need for their vital functions. The method of supplying an external energy source that may act as a precursor of ATP, such as inosine, has proved to be protective from a functional point of view. In this work, we aim to reveal the histological ultrastructural bases that underlie this protective effect. METHODS: We studied two groups of rats subjecting the kidneys to different durations of warm ischemia, and compared the histological findings at various parts of the nephron after perfusion with saline or inosine. These findings were compared, in turn, with the normal morphology of a third control group. RESULTS: The histological findings were: 1. No significant lesions after 60 and 120 min of warm ischemia in animals perfused with inosine; and 2. Glomerular and tubular injury after 60 min of warm ischemia in animals perfused with saline. CONCLUSIONS: The saline-perfused animals showed very significant injury at the glomerular and tubular levels after 60 and 120 min of warm ischemia. These lesions were not seen in animals perfused with inosine. The similarity of the morphological findings between the inosine-infused group and the control group suggests that inosine has a protective effect on the morphology of the rat nephron under conditions of warm ischemia for periods shorter than 120 min.

Estudio ultraestructural del riñón sometido a isquemia normotérmica y perfundido con inosina / Ultrastructural study of the kidney subjected to warm ischemia and perfused with inosine

OBJETIVO: La isquemia renal da lugar a la pérdida de función del órgano, en mayor o menor medida, dependiendo del tiempo de la misma como consecuencia del agotamiento de las reservas energéticas que la célula utiliza para sus funciones vitales. El aporte externo de una fuente de energía en forma de un precursor de ATP, como es la INOSINA, ha demostrado ser un método protector desde el punto de vista funcional. Pretendemos en éste trabajo poner de manifiesto las bases histológicas ultraestructurales en las que se basa dicho efecto protector. MÉTODO: Se estudian básicamente dos grupos de ratas y se comparan los hallazgos histològicos de las distintas partes de la nefrona después de perfundirlos con suero fisiológico ó inosina y someter los riñones a distintos tiempos de isquemia normotérmica. Dichos hallazgos se comparan a su vez con la morfología normal de un tercer grupo testigo. RESULTADOS: Los hallazgos histológicos se concretan en: 1- Ausencia de lesiones significativas en los animales perfundidos con inosina a los 60 y 120 min. de isquemia normotérmica. 2- Lesiones glomerulares y tubulares a partir de los 60 min de isquemia normotérmica en los animales perfundidos con suero fisiológico. CONCLUSIONES: Los animales perfundidos con suero fisiológico mostraron lesiones muy importantes a nivel glomerular y tubular a los 60 y 120 min de isquemia normotérmica. Dichas lesiones no se aprecian en los animales perfundidos con inosina. La similitud de los hallazgos morfológicos del grupo perfundido con inosina y el grupo testigo, permite atribuir a la inosina un efecto protector de la morfología de la nefrona de rata bajo condiciones de isquemia normotérmica en periodos inferiores a 120 min (AU)

OBJECTIVES: Renal ischemia, depending on its duration, results in organ function loss to a greater or lesser extent, due to the depletion of the energy cells need for their vital functions. The method of supplying an external energy source that may act as a precursor of ATP, such as inosine, has proved to be protective from a functional point of view. In this work, we aim to reveal the histological ultrastructural bases that underlie this protective effect. METHODS: We studied two groups of rats subjecting the kidneys to different durations of warm ischemia, and compared the histological findings at various parts of the nephron after perfusion with saline or inosine. These findings were compared, in turn, with the normal morphology of a third control group. RESULTS: The histological findings were: 1 ) No significant lesions after 60 and 120 min of warm ischemia in animals perfused with inosine; and 2) Glomerular and tubular injury after 60 min of warm ischemia in animals perfused with saline. CONCLUSIONS: The saline-perfused animals showed very significant injury at the glomerular and tubular levels after 60 and 120 min of warm ischemia. These lesions were not seen in animals perfused with inosine. The similarity of the morphological findings between the inosine-infused group and the control group suggests that inosine has a protective effect on the morphology of the rat nephron under conditions of warm ischemia for periods shorter than 120 min (AU)

Cellular proliferation in the rat pineal gland during postnatal development.

To establish a possible correlation between the rate of cellular proliferation and already documented functional and morphological characteristics of the rat pineal gland during postnatal development, the bromodeoxyuridine labelling method was used to evaluate the fraction of cells at the S phase of the cell cycle in paraffin sections from 1-, 7-, 14- and 28-day-old rats. Numerical density, taken as an indirect measure of cell hypertrophy, was also evaluated. During the first week after birth the percentage of S phase-cells in the rat pineal gland sharply decreased from around 9% to 1.3%. A smaller but also significant decrease was found from the 7th to the 14th postnatal day where S phase cells were less than 0.5% of all pineal cells. A very low percentage was also seen in samples from 28-day-old rats. Numerical density, namely, the total number of cells per surface unit of pineal section, decreased from birth to the end of the first month. This decrease was also steeper from birth to the 7th postnatal day than at any other period of the study. These results support the idea that a strong expansion of the cellular population of the rat pineal gland precedes morphological and functional maturation and opens the way to further exploration of the relationship between functional and proliferative responses of the pineal gland.