Objective: Numerous studies have shown that a methionine-rich diet induces hyperhomocysteinemia (Hhcy), a risk factor for cardiovascular diseases. The objective of the present study was to determine the involvement of Hhcy in cardiac remodeling in the sand rat Psammomys obesus. Materials and methods: An experimental Hhcy was induced, in the sand rat Psammomys obesus, by intraperitoneal injection of 300 mg/kg of body weight/day of methionine for 1 month. The impact of Hhcy on the cellular and matricial structures of the myocardium was analyzed with histological techniques (Masson trichrome and Sirius red staining). Immunohistochemistry allowed us to analyze several factors involved in myocardial remodeling, such as fibrillar collagen I and III, metalloproteases (MMP-2 and -9) and their inhibitors (TIMP-1 and -2), TGF-beta 1 and activated caspase 3. Results: Our results show that Hhcy induced by an excess of methionine causes, in the myocardium of Psammomys obesus, a significant accumulation of fibrillar collagens I and III at the interstitial and perivascular scales, indicating the appearance of fibrosis, which is associated with an immuno-expression increase of TGF-131, MMP-9 and TIMP-2 and an immuno-expression decrease of MMP-2 and TIMP-1. Also, Hhcy induces apoptosis of some cardiomyocytes and cardiac fibroblasts by increasing of activated caspase 3 expression. These results highlight a remodeling of cardiac tissue in hyperhomocysteinemic Psammomys obesus.

We study the effect of an enriched cholesterol-methionine diet administered to females on the cardiac tissue remodelling of the offspring during two successive pregnancies. Two groups are constituted, standard diet (SD) group fed a standard diet and CD group fed a combined diet (standard + cholesterol 1%-methionine 0.25%). The diet is administered during 80 days. The results show changes in serum and cardiac parameters of CD newborn, with the involvement of phospholipids (PLs) (phosphatidylethanolamine (PE) and phosphatidylcholine (PC), variations in malondialdehyde (MDA), conjugated diene (CD), and vitamin C [VIT-C] rates). Under the CD effect, serum matrix metalloproteinase (MMP)-2, pro-MMP-9, and MMP-9 activities change. As to cardiac MMP-2 activity, a rise is noticed in the second pregnancy. Histological analysis reveals constricted blood capillaries, collagen fibre deposits, and lipid accumulation in the CD newborn heart. Our study shows the amplified effect of the maternal cholesterol-methionine diet in the second pregnancy on newborn cardiac disorders (matrix remodelling, oxidative stress, and lipid accumulation).

Introduction. The sand rat, Psammomys obesus, a diurnal rodent, which lives in the south-east of the Algerian Sahara, is an excellent animal model for the study of diabetes, atherosclerosis, and metabolic syndrome. Hyperhomocysteinemia (Hhcy), defined by high plasma homocysteine level, is associated with many diseases affecting various organs (heart, blood vessels, liver…). Objectives. The objective of this study was to determine the effect of Hhcy on the sand rats pancreas. Material and methods. The rats were divided into two groups: a control group received its natural diet with halophile plant of the Chenopodiacae family (Suaedamollis), and an experimental group received the same diet associated with an intraperitoneal administration of methionine (150 mg/kg body weight/day) during 6 months. Histological and histochemical analysis of Psammomys pancreas were realized and completed by a morphometric study. Results. The methionine excess led to a hyperhomocysteinemia in Psammomys obesus. Several alterations were observed in pancreas extracellular matrix of hyperhomocysteinemic rats, marked by an accumulation of fibrillar collagens, and glycoproteins leading to a fibrosis. This accumulation was observed in the Langerhans islets, and in the exocrine pancreas (interstitial tissue, around blood vessels, and excretory channels). A disorganization of the vascular wall, and a micro- and macrovesicular steatosis were also observed in the pancreas of hyperhomocysteinemic rats. Conclusion. The hyperhomocysteinemia, generated by the methionine excess, leads to a pancreatic extracellular matrix remodeling in Psammomys obesus.

Early weight gain induced by high-fat diet has been identified as a predictor for cardiac disease, one of the most serious public health problems. Our goal is to study the influence of a HFD on biochemical, oxidant stress parameters, and the cardiac ultrastructure in both male and female prepubertal models. Experiments were carried on 24 prepubertal New Zealand white rabbits, randomly assigned to male and female control (MC and FC, resp.) or HFD (MHFD and FHFD, resp.) groups (n = 6) for 3 months. Body and heart weights and some biochemical and oxidative stress parameters such as lipids, calcium, CKMB, MDA, uric acid, ascorbic acid, and AOA are evaluated in plasma and the left ventricle. Under HFD effect, plasma parameters, such as lipids (TL, PL, and LDL-C), MDA, and CK-MB, increase more significantly in male than in female groups, when AA decreases. Some cardiac parameters such as TG and UA increase, when AA and AOA decrease; these variations are more significant in FHFD. In both male and female rabbits, HFD caused changes in heart ultrastructure, junctional complexes, mitochondria size and form, and so on. Early HFD feeding induced overweight, oxidative stress, and metabolic alterations in plasma and the heart of prepubertal rabbits, whereas lipotoxicity has especially a negative impact on male plasma but affects more the female heart ultrastructure.

Background: The aim of the study is to compare the effects of hyperhomocysteinemia induced by methionine overload on lipid parameters and structure of the aorta in both male and female rabbits. Materials and methods: Study is carried on 20 male rabbits (control, n=11 and experimented, n=9) and 16 female rabbits, control (n=8) and tested (n=8). Control models are fed standard diet, the Met females and males received standard diet supplemented with Met (500 mg/day) during 3 months. Results obtained from MetM and MetF are compared with those of the respective controls. The body weight is measured, the parameters, Hcy, total cholesterol, total lipids, TG, atherogenicity index ((VLDL+LDL)/ HDL) are determinate by appropriate methods (FPIA, colorimetry). In aorta tissue we assess the total lipids, TC and TG contents and realize a histological study (Masson's staining). Results and discussion: the Met-enriched diet causes a low increase of Hcy (p<0.05) in male, but a significant increase in female (p<0.0001). The TG raise in male (p<0.01) and diminish in female (p<0.01). Atherogenicity index augments from 1,31 to 1,52 in male and from 2,17 to 3,07 in female. At the aortic level, while in male rabbit the total lipid, TC and TG raise significantly (p<0.01), in female TL decrease but TC and TG increase (p<0.01). Aorta of Met female undergoes severe histological changes, such as endothelium hypertrophy, local rupture of the internal elastic lamina, remodelling of media with accumulation of collagens. The observations made in Met male are less important, but the elastic blades present irregular assemblies. Conclusion: Under Met overload, the female aorta tissue presents the most spectacular changes of biochemical as well as histological parameters.

This study investigated whether a high Met diet influences biochemical parameters, MMPs activities in plasma, and biochemical and histological remodeling in aorta, in both pregnant female rabbits and their offspring. Four female rabbit groups are constituted (each n = 8), nonpregnant control (NPC), pregnant control (PC) that received normal commercial chow, nonpregnant Met (NPMet), and pregnant Met (PMet) that received the same diet supplemented with 0,35% L-methionine (w/w) for 3 months (500 mg/d). All pregnant females realize 3 successive pregnancies. Plasma results showed that Met excess increased Hcy, raised CRP in NPMet and decreased it in PMet, enhanced significantly proMMP-2 and proMMP-9 activities in NPMet, and reduced them in PMet. Aorta showed a rise in collagen level, essentially in PMet, a reduction of elastin content in both PMet and NPMet, and a significant decrease in lipid content in PMet, with histological changes that are more pronounced in NPMet than PMet. Met excess enhanced proMMP9 activities in NPMet while it decreased them in PMet. PMet newborn presented increase in uremia and CRP and significant rise of active MMP-2 and MMP-9 forms. In aorta, media and adventitia thickness increased, total lipids content decreased, proMMP-9 activity decreased, and proMMP-2 activity increased.

Le foie est un organe important intervenant dans le métabolisme de l’homocystéine. L’excès d’homocystéine conduit à une hyperhomocystéinémie, considérée comme facteur de risque émergeant et/ou indépendant des maladies cardiovasculaires. Ce travail avait pour objectif d’analyser l’impact d’une hyperhomocystéinémie sur la structure hépatique du rat des sables, Psammomys obesus, rongeur déserticole du sud algérien, reconnu comme étant un excellent modèle d’étude des maladies cardiovasculaires. Pour ce faire, les rats des sables ont été répartis en deux lots : un lot témoin nourri à l’aide de plantes halophiles de la famille des Chenopodiacées et un lot rendu hyperhomocystéinémique par administration de méthionine à raison de 150 mg/kg de poids corporel/j pendant 6 mois. Une approche histologique, histochimique à l’aide de colorations appropriées (colorations au trichrome de Masson et à l’acide périodique Schiff) a permis d’analyser la structure hépatique des rats des sables. Cette étude est complétée par une approche morphométrique portant sur la taille et le nombre des hépatocytes, la surface nucléaire hépatocytaire, la surface des capillaires sinusoïdes et le nombre de cellules de Kupffer. Nos résultats ont mis en évidence la présence d’atteintes matricielles, cellulaires et vasculaires. En effet, la structure hépatique est le siège d’une modulation de la composition de la matrice extracellulaire caractérisée par une accumulation de glycoprotéines et collagènes fibrillaires responsable de l’installation d’une fibrose interstitielle et périvasculaire. Nous avons également observé une stéatose micro et macrovésiculaire. En outre, l’étude morphométrique effectuée sur 100 mesures, a mis en évidence une diminution d’environ 45 % (p < 0,0001) du nombre des hépatocytes associée à une hypertrophie cellulaire et une augmentation de la surface nucléaire (39 %, p < 0,0001). Le nombre de cellules de Kupffer ainsi que la surface des capillaires sinusoïdes augmentaient respectivement de 26 % (p < 0,01) et 28,4 % (p < 0,01) chez les rats des sables hyperhomocystéinémiques. Chez le rat des sables, Psammomys obesus, l’hyperhomocystéinémie induite par un excès de méthionine est à l’origine d’un remodelage de la structure hépatique marqué par une fibrose, une stéatose et des atteintes cellulaires et vasculaires.

Methionine is the only endogenous precursor of homocysteine, sulfur-containing amino acid and well known as risk factor of cardiovascular disease, The aim of this study is to determinate the histological and biochemical modification in cardiac tissue, induced by methionine nutritional overload. Twenty adult male rabbits were randomly divided into control and experimental group fed for 3 month with standard or methionine- enriched diet (500 mg of L-Met D / kg / day), respectively. Gomori's argentic impregnation and Van Gieson staining were performed to observe pathologic changes of left heart ventricle. The levels of total protein, thiobarbituric acid reactive substances (TBARS), alanine aminotransferase (ALT) and aspartate transaminase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) were measured, in plasma and cardiac tissue, by enzymatic methods. The results obtained, in our conditions, shows that Met supplementation increases the plasmatic TBARS in the first month (p<0.05) of the experimentation comparing to the control group, however, in the end of the experimentation (3rd month) both plasmatic and cardiac TBARS shows no variation compared to control group. A plasmatic increase in both AST (32.13±3,5U /L vs 21.37±2.42 U /L) and peculiarly ALT (26.65±8 55 U /L vs 50.05±12.86 U /L); PAL activity increases gradually until the 3rd month. No significant variation is observed in LDH, transaminase and PAL in cardiac tissue. Cardiac histology reveals a reduction in the connective tissue content with the appearance of chronic local inflammation and apoptosis, structural abnormalities in large coronary vessels with Hyperplasia of smooth muscular cells. Methionine overload causes biochemical disorders and structural alterations in the heart tissue. The author hereby declares no conflict of interest

the objective of this study is to determine the correlation between hyperhomocysteinemia and lipid status of male rabbit. our study carried on 30 male rabbits divided into three groups, Control (n=11) received standard diet and experimented Met1 (n=9) received standard diet supplemented with 500mg Met/day during 3 months, and Met2 (n=10) received standard diet with Met overload, 1500 mg/day, during 2 months. The monitoring concerns the body weight measure, homocysteinemia (FPIA method) and the cholesterolemia, LDL-C, HDL-C, triglyceridemia, NEFA determinations and atherogenicity index. the methionine overload caused a low increase of homocysteinemia in tested groups rabbits compared to the control one (Gong et al., 2008).This variation seemed not important to create body weight variation. This hyperhomocysteinemia caused a rise of atherogen lipid fractions; CT, LDL-C, NEFA and diminution of HDL-C in tested groups compared to the control one (Borsheim et al. 2009).The TG seemed no affected by this diet (Fernane, 2009). our results are similar to results of literature, indicating that atherogenicity of hyperhomocysteinemia is mediated by deterioration of lipid status. The author hereby declares no conflict of interest

The biochemical cardiac and plasmatic damages induced by high-fat diet were examined in male and female rabbit and compared to the control models. Experiments were carried on 24 pre-pubertal New Zealand white rabbits, 12 males and 12 females, randomized into 4 groups (for each, n=6), 2 control groups, male (MC) and female (FC) fed a normal fat diet, and 2 High Fat Diet groups (MHFD, FHFD). HFD contained 1g of peanut butter +0.5g of animal fat. Body and heart weights were compared between the groups. Glucose, total proteins, uric acid, TG, cholesterol, phosphorus and phospholipids were examined by enzymatic methods in the plasma. The total lipids extracted from heart (Folch, 1957) were analyzed by TLC. Results obtained with HFD are compared with those of standard diet. At the end of experiment, the results showed a modest raise of body weight among MHFD vs MC, but very significant among FHFD vs FC (p<0,0001), also a significant increase of heart weight among FHFD vs MHFD, and a small raise of glycemia among MHFD vs FHFD (p<0,05).With HFD, the levels of proteins, uric acid and HDL-C were similar between female and male. The cholesterol showed a small raise in both MHFD and FHFD vs controls (p<0,05). LDL-C increased very significantly among MHFD vs MC (p<0,0001) and among FHFD vs FC(p<0,0001).There was a small raise of phospholipids in both FHFD and MHFD (p<0,05), also a small raise of TG among FHFD vs MHFD(p<0,05).In the heart, there was a small raise of total lipids for both MHFD and FHFD vs controls (p<0,05), and a small raise of phosphorus among MHFD vs FHFD, also a little raise of proteins among FHFD vs MHFD (23,85±2,61 mg/g vs 19,98±0,46 mg/g of heart).The TLC showed an increase of lipid levels among MHFD vs MC, also among FHFD vs FC. Diet supplemented with peanut butter and animal fat is responsible for major metabolic alterations in the heart and plasma of pre-pubertal male and female rabbits. The author hereby declares no conflict of interest

L'administration de régime enrichi en méthionine conduit à un état d'hyperhomocystéinémie secondaire, caractérisé essentiellement par un remodelage de la composition de la matrice extracellulaire. Dans cette étude, nous recherchons les effets de la modification du taux d'homocystéine sur la structure du testicule et les cellules germinales du lapin domestique. L'étude a porté sur 29 lapins domestiques divisés en trois lots, un lot témoin (n = 11) et un lot expérimenté Met 1(n = 9) soumis à la méthionine per os à raison de 500 mg/jour /animal pendant 3 mois, un lot Met 2 (n = 9) soumis à une dose de dose élevée (1,5 g de Met par jour) pendant deux mois. Le suivi des modèles animaux se fait par pesée et prise sanguine hebdomadaires. La détermination de l'homocystéinémie est effectuée par la méthode immunologique (FPIA). A la fin de l'expérimentation, les modèles animaux sont sacrifiés, entre autres tissus, les gonades sont prélevés, fixés dans du bouin aqueux puis soumis à une analyse topographique par coloration au trichrome de Masson ainsi qu'à une étude histochimique par coloration au bleu alcian et au PAS. (Martoja et Martoja, 1967). Cette analyse est complétée par une étude morphométrique des épaisseurs d'albuginée et de vitrée ainsi qu'une estimation de la spermatogenèse par comptage du nombre de tubes séminifères et de spermatozoïdes. A la fin de l'expérimentation, l'homocystéinémie montre une augmentation peu significative pour le lot Met 1 mais pour le lot Met 2 elle est de 200 %. L'augmentation de l'homocystéinémie engendrée par ce régime ne semble pas interférer avec l'évolution du poids moyen des différents lots de lapins. L'analyse morp ho métrique des gonades des lapins soumis à la méthionine montre une augmentation de l'épaisseur de l'albuginée, qui est 85 % pour le lot Met1 et de 130 % pour le lot Met2. L'épaisseur de la vitrée est soumise à l'influence du régime enrichi à la méthionine de façon hautement significative (p < 0,0001) puisque les valeurs passent de 2,26 +/−0,64 μm chez les témoins à 3,18 +/-0,80 μm et 3,4 +/-0,86 μm chez les lots Met1 et Met2 respectivement. Le matériel accumulé au niveau des 2 enveloppes semble être de nature glycoprotéique et protéoglycane, tel que révélé par l'étude histochimique (colorations PAS et bleu alcian). Au niveau du tissu interstitiel, il est noté l'installation d'une fibrose périvasculaire avec accumulation des composants de la matrice extracellulaire notamment les collagènes, glycoprotéines, protéoglycanes. Au niveau des tubes séminifères soumis à la Met, il y a présence de quelques cellules à noyaux apoptotiques et une nette diminution dose-dépendante du nombre de spermatozoides qui atteint les 79,6 % pour le lot Met1 et 84,9 % pour le lot Met2. L'hyperhomocystéinémie conséquente à une surcharge en méthionine engendre des altérations de la structure gona-dique et altère la fonction testiculaire pouvant conduire à l'infertilité du mâle. Toutes les variations notées au niveau testiculaire sont dose-dépendante de la méthionine ingérée.

The adrenals synthesize many hormones involved in the regulation and maintenance of homeostasis. To understand the pathophysiological changes during the development of obesity, a histological study of the adrenal was performed in gerbils receiving a high-fat/high-carbohydrate-diet (HFC) for 8 or 12 weeks. Compared to the controls, the HFC diet increased body weight. Our results reveal significant weight and structural changes in the HFC group’s adrenal glands (confirmed by gray level co-occurrence matrix texture and fractal analysis), disorganization of zona fasciculata (8 weeks) and hyperplasia and peri-capillary fibrosis (12 weeks). In conclusion, these results show that an HFC induces time-dependent structural lesions of the adrenals in gerbils, which could be a sign of chronic adaptation of these glands.