Alternatives to Animal Experimentation: Its Institutional Teaching and Scientific

Although it is desirable to replace scientific procedures with live animals by other methods that do not use them, the use of animals in scientific procedures should be restricted to those areas that benefit human, animal, and environmental health. The use of animals as experimental models of observation of biological phenomena has evolved with man, to this day. The use of animals for scientific or educational purposes should be considered only when there is no other alternative and it is governed by the principles of replacement, reduction, and refinement. The scientists should be sure that the information obtainable with the experiments is not yet available or that the protocol was designed taking into account animal protection considerations. The chosen methods must use the least number of animals; provide satisfactory results; use the species with the least ability to experience pain, suffering, anguish, and damage; and be optimal for the extrapolation of results to the target species such as humans. It will be fundamental to guarantee on a scientific and ethical basis that the use of an animal is subject to a careful evaluation regarding the scientific or educational validity

Sympathectomy Effects on Intra-Abdominal Organ Catecholamine Levels in a Streptozotocin-Induced Diabetic Rat Model

Diabetes mellitus (DM) is a metabolic disorder whose prevalence has continuously increased worldwide and is associated with dysfunction of the autonomic nervous system and, in particular, that of the sympathetic nervous system (SNS). The objective of this study was to analyze the interaction of DM and the SNS, building a model of sympathectomized diabetic rats to determine alterations in the content of CA (catecholamines) in different intra-abdominal organs. Sympathectomy was conducted with guanethidine (GNT). Additionally, DM was induced with STZ (Streptozotocin). Treatment with GNT decreased norepinephrine (NE) content in all analyzed tissues, with significant differences found in the paraganglia, liver, pancreas, duodenum, and heart compared to the control group. With respect to epinephrine (E), which was only found in the liver, pancreas, and heart, presenting significant differences (p < 0.05) in the heart, a decrease in its concentration was observed for all of the experimental groups with respect to the control. The decrease in dopamine (DA) content due to the GNT–STZ treatment was 30.1% in the heart with respect to the diabetic (STZ) group. The amount of CA in the adrenal medulla indicates the effect of sympathectomy on the GNT group where there was a significant reduction (p < 0.05) of DA. These findings suggest that the elimination of the sympathetic nervous system in diabetic organisms contributed to a decrease in blood glucose; likewise, an alteration in the levels of CA was observed in the different selected organs, possibly attributed to the severity, duration, and pathogenesis of the complications of acute and chronic DM

Effect of Spirulina (Formerly Arthrospira) Maxima against Ethanol-Induced Damage in Rat Liver

Spirulina (formerly Arthrospira) maxima (SP) is a cyanobacterium reported to have great nutritional and pharmacological potential. The objective of this study was to evaluate the protective properties of SP against ethanol-induced toxicity. Male Wistar rats were used in the study and subjected to a 70% partial hepatectomy (PH); they were then divided into five groups. During the experiment, animals in two groups drank an aqueous solution of ethanol (EtOH) (40%, v/v). Additionally, they were administered an SP extract daily at a dose of 200 mg/kg body weight intragastrically. To explore possible mechanisms of action, we examined antioxidant defense enzymes, as well as serum biochemical parameters and histopathological changes in the liver. SP administration normalized elevated glutathione reductase (GR), glutathione (GSH), and superoxide dismutase (SOD) levels, in addition to increased catalase (CAT) and glutathione peroxidase (GPX) enzymes. Alterations in biochemical parameters were observed in the groups with PH treated with EtOH associated with a reduction in cholesterol and albumin levels, while glucose and triglyceride levels increased. The histological study supported the protective activity of SP, reducing apoptosis, necrosis, and congestion in the liver. Our findings demonstrated a protective effect of SP against EtOH that is related to less inflammation, a lesser antioxidant effect, and less free radical scavenging activity