Collagenous and elastic system fibres in the aorta of cattle poisoned by Solanum glaucophyllum

PDE5 inhibition improves cardiac morphology and function in SHR by reducing NHE1 activity: Repurposing Sildenafil for the treatment of hypertensive cardiac hypertrophy

Previously, we have shown that an increased cGMP-activated protein Kinase (PKG) activity after phosphodiesterase 5 (PDE5) inhibition by Sildenafil (SIL), leads to myocardial Na+/H+ exchanger (NHE1) inhibition preserving its basal homeostatic function. Since NHE1 is hyperactive in the hypertrophied myocardium of spontaneous hypertensive rats (SHR), while its inhibition was shown to prevent and revert this pathology, the current study was aimed to evaluate the potential antihypertrophic effect of SIL on adult SHR myocardium. We initially tested the inhibitory capability of SIL on NHE1 in isolated cardiomyocytes of SHR by comparing H+ efflux during the recovery from an acid load. After confirmed that effect, eight-month-old SHR were chronically treated for one month with SIL through drinking water. Compared to their littermate controls, SIL-treated rats presented a decreased NHE1 activity, which correlated with a reduction in its phosphorylation level assigned to activation of a PKG-p38 MAP kinase-PP2A signaling pathway. Moreover, treated animals showed a decreased oxidative stress that appears to be a consequence of a decreased mitochondrial NHE1 phosphorylation. Treated SHR showed a significant reduction in the pro-hypertrophic phosphatase calcineurin, despite slight tendency to decrease hypertrophy was detected. When SIL treatment was prolonged to three months, a significant decrease in myocardial hypertrophy and interstitial fibrosis that correlated with a lower myocardial stiffness was observed. In conclusion, the current study provides evidence concerning the ability of SIL to revert established cardiac hypertrophy in SHR, a clinically relevant animal model that resembles human essential hypertension.

Comparison of the structural and ultrastructural characteristics of the female prostate between pregnant and non-pregnant plains viscacha (Lagostomus maximus)

Some years ago, our group reported the presence of the female prostate in all the studied females of the plains viscacha (Lagostomus maximus). The goal of the present study was to characterize and compare the female prostate gland between adult pregnant and non-pregnant plains viscacha using histochemical, lectin-histochemical and immunohistochemical techniques, as well as optic and electron microscopy. Structurally, alveoli are lined by a simple epithelium formed by different cell types: basal cells, secretory cells in different stages of the secretory cycle and cells of clear cytoplasm. Secretory cells are the most abundant cell type, differing between them depending on the quantity and electron-density of their granules. The basal cells are less abundant and are responsible for the renewal of the alveolar epithelium. Likewise, other cells with secretory morphology were found in all the studied females; these have a clear cytoplasm, few granules and mitochondria. It could be considered that they are degranulated secretory cells or that they have partially released their granules. The stroma of the organ is formed by connective tissue and smooth muscle fibers, which are immunohistochemically evidenced against desmin. Histochemical and lectin-histochemical analysis revealed the presence of different glucidic residues in the different cell types. No structural, histochemical, lectin-histochemical, and ultrastructural differences were observed between pregnant and non-pregnant females of plain viscachas, except for the expression of some lectins. The paraurethral gland of Lagostomus maximus can be used as a model for studying the gland in other species since its structural and ultrastructural characteristics do not depend on the hormonal status of the female.

Enzootic calcinosis in horses grazing Solanum glaucophyllum in Argentina

Solanum glaucophyllum, a toxic plant known for its calcinogenic effects, causes enzootic calcinosis in ruminant and monogastric animals. We describe an outbreak of enzootic calcinosis that occurred in a herd of 110 horses grazing pastureland heavily contaminated with S. glaucophyllum in Buenos Aires province, Argentina. Ten horses developed clinical signs, and 6 horses died. Clinical signs included abnormal gait (stiff-legged action, short strides), stiffness, thoracolumbar kyphosis, reluctance to move, wide stance, chronic weight loss, weakness, recumbency, and difficulty standing. Autopsy of 2 horses revealed severe mineralization of the aorta, pulmonary arteries, heart, and lungs, consistent with enzootic calcinosis. Although horses usually have very selective grazing behavior, under food restriction conditions, they can ingest the toxic plants and can develop the disease. Enzootic calcinosis should be considered as a differential diagnosis in horses grazing S. glaucophyllum-invaded pasturelands with compatible clinical signs and lesions.

Effects of Solanum glaucophyllum toxicity on cell proliferation and apoptosis in the small and large intestine of rabbits

Vitamin D regulates mineral homeostases and enterocyte proliferation and differentiation. Hypervitaminosis D generates changes in cell proliferation, differentiation and apoptosis in several organs. We analysed morphometric parameters and proliferative and apoptotic indices in the intestinal epithelium of rabbits with hypervitaminosis D induced by the chronic treatment with the calcinogenic plant Solanum glaucophyllum. Rabbits were treated for 15 or 30 days. A group was treated for 15 days and led to possible recovery for 30 days. Another group was nutritionally restricted for 30 days. Morphological, morphometric, proliferative and apoptotic changes were found in the treated animals. Mild atrophy and reduced proliferation was found in the jejunum and ileum. Apoptosis increased in the crypts of the ileum and in the superficial epithelium and crypts of the rectum. Most of the alterations were partially recovered. The possible involvement in these changes of the hypervitaminosis D-like state induced by S. glaucophyllum is discussed.