Obtención y Análisis del Espectro de Absorción Óptico de Sangre de Rata Fisher con Daño Hepático Mediante Espectroscopia Foto acústica / Obtaining and Analysis of Optical Absorption Spectrum of Fisher Rat Blood with Hepatic Damage by Photoacoustic Spectroscopy

Resumen: La Espectroscopia Fotoacústica (EFA), ha destacado de entre las técnicas fototérmicas por su versatilidad para la caracterización de diversos tipos de muestras, incluyendo las de tipo biológicas. En este estudio, se compararon y analizaron mediante EFA, las diferencias entre los espectros de absorción ópticos de sangre de ratas macho Fisher en tres casos, control (ratas sanas), con daño hepático, y con daño hepático tratadas con Curcuma longa. Los resultados experimentales demostraron diferencias en los espectros de absorción ópticos de cada caso analizado, por lo que EFA se propondría como una técnica complementaria, no convencional para el estudio del efecto de la Curcuma longa en daño hepático inducido en modelo animal.

Abstract: Photoacoustic Spectroscopy (PAS) stand outs among Photothermal techniques due to its versatility for the characterization of different types of materials, including biological samples. In this study, were compared and analyzed by PAS, the differences between the optical absorption spectra of blood of male Fisher rats, in three cases, control (healthy rats), liver damage and liver damage treated with Curcuma longa. The experimental results show differences in the optical absorption spectra of each analysed case, therefore PAS would be proposed as a non conventional complementary technique, to study the effect of Curcuma longa in induced liver damage for an animal model.

Effects of long-term high-sucrose and dexamethasone on fat depots, liver fat, and lipid fuel fluxes through the retroperitoneal adipose tissue and splanchnic area in rats.

In affluent societies high caloric intake and chronic stress are currently associated with upper body fat. We investigated the effects of a high-sucrose (S) diet and dexamethasone (DEX) on fat depots (experiment 1) and lipid fuel fluxes (experiment 2) in male Wistar rats. In experiment 1, a liquid diet of commercial powdered milk containing 31% calories as carbohydrate or an isocaloric S diet (80% calories as carbohydrate) was offered to male rats. One half of the rats on each diet received a daily dose of 3 microg DEX in their diet. Intake was measured daily and body weight 3 times a week. Rats were killed after 7 weeks, and fat depot weights and carcass lipid were determined. In a second experiment, other rats received only the S diet with or without DEX. After 7 weeks, under pentobarbital anesthesia, arterial, portal, and iliolumbar vein blood was drawn, and the liver was extracted. Plasma concentration of triacylglycerides (TAG), nonesterified fatty acids (NEFA), glycerol (GOL), and lactate (L) and liver TAG were measured. Rats on the S diet ingested less and gained less weight. DEX treatment significantly reduced body weight gain. All fat depots as percentage of body weight were increased only in the S-DEX group. The S-DEX group had more liver TAG and less arterial NEFA and GOL than the S group. TAG determinations showed unexpected results: portal levels in the S-DEX group and iliolumbar levels in both groups were significantly higher than in the arterial plasma. This fact, together with high NEFA/GOL ratios in these veins, may signify incomplete TAG hydrolysis by lipoprotein lipase. L levels were higher in the S-DEX group and higher in arterial versus venous blood in both groups, indicating L uptake both in the splanchnic area and the retroperitoneal fat. These results show that, in rats, a long-term high-sucrose diet has peculiar effects on L turnover, and when associated with DEX, it also increases fat depots, induces liver steatosis, and, presumably, inhibits complete hydrolysis of TAG by lipoprotein lipase (LPL).

3,5,3'-Triiodothyronine administered to rat dams during lactation increases milk yield and triglyceride concentration and hastens pups growth.

It is known that lactation induces a mild hypothyroid state in rats and other mammals while thyroid hormone administration increases milk secretion in ruminants. The aim of this study was to investigate the effects of a moderate dose of 3,5,3'-triiodothyronine (T3), administered to rat dams during lactation on pups' growth and milk yield and composition. Primiparous Wistar rats with litters adjusted to 10 pups per dam received either tap water or T3 (75 microg/kg x day) in their drinking water from parturition till weaning. Food and water intake of dams and body weight of dams and pups were measured daily. In other groups of rats with similar treatments, milk yield of dams, macronutrient milk composition, and mammary arteriovenous differences for triglycerides (TG) and glucose were also determined. Dams treated with T3 ingested more food and their pups gained more weight than controls. Milk yield, milk TG concentration and glucose extraction by mammary glands were also higher in T3 treated dams. The results show that compensation of the mild hypothyroidism of the lactating rat may contribute to an increase in milk production and lipid levels, leading to an increase in growth of pups.