Morphological abnormalities and apoptosis in lamellar tissue of equines after intestinal obstruction and treatment with hydrocortisone

Abstract

Four experimental groups of equines were used in order to study morphological abnormalities and apoptosis in lamellar tissue. Group Cg (control) was composed of animals without any surgical procedure; group Ig (instrumented), animals that underwent enterotomy; group Tg (treated), animals that were subjected to intestinal obstruction and were treated with hydrocortisone; and group Ug (untreated), animals that were subjected to intestinal obstruction without treatment. The lamellar tissue was analyzed regarding the presence of tissue abnormalities and apoptosis. No morphological abnormalities were observed in animals of surgical groups, and no difference in apoptosis was observed between groups. It was concluded that intestinal obstruction allowed laminitis to develop, probably by systemic activation, and that the maneuvers performed in the enterotomy aggravated the process. Hydrocortisone did not aggravate the lesions of the lamellar tissue.Keywords: equine, laminitis, apoptosis, intestinal obstruction, morphological abnormalities RESUMO Foram utilizados quatro grupos de equinos para estudar alterações morfológicas e apoptose no tecido lamelar. O grupo CG (controle) foi composto por animais sem o procedimento cirúrgico; o grupo

An update on equine laminitis

“…The disease can also be induced in healthy horses via insulin administration (DE LAAT et al, 2010), in an experimental model related to secondary laminitis to endocrine changes. BELKNAP et al (2011) ischemia can also promote lesions in the laminar tissue (RIO TINTO et al, 2004;LASKOSKI et al, 2010), which is supported by severe changes in laminar tissue reported in horses with natural colic syndrome not yet evidencing clinical signs of foot disease (LASKOSKI et al, 2009).…”

“…There is an increased apoptosis in horses with laminitis naturally acquired until a week of evolution when compared to horses in the prodromal and chronical phase of the disease (FALEIROS et al, 2004). Increase of apoptotic cells was not observed in equines with experimental intestinal obstruction, which did not show clinical signs of laminitis, but laminar morphological changes (LASKOSKI et al, 2010). Thus, the occurrence of apoptosis may be associated with the severity of the lesions found in an attempt to cell renewal, after the prodromal phase of the disease, when clinical symptoms are manifested.…”

“…Endotoxin, one of the most common PAMPs was detected in the blood of horses after laminitis induced for carbohydrate administration (BAILEY et al, 2009 There is evidence that laminitis may occur secondarily to systemic inflammatory response (FALEIROS et al, 2008). LASKOSKI et al (2010) observed changes in the laminar tissue of horses after intestinal obstruction, probably due to systemic inflammatory activation triggered by ischemiareperfusion injury that occurs in gastrointestinal disorders (RIO TINTO et al, 2004). FALEIROS et al (2011a and2009b) showed increase of chemokines in equine hoof with laminitis related to carbohydrate overload induction, which are linked to the activation and laminar leukocyte migration.…”

“…Classification of severity changes in laminar tissue is surrounded by alterations in the nuclei of basal cells, shape of the secondary epidermal laminar and the outline of the basal membrane. The most severe cases of laminar injury includes total destruction of the interdigitations, with consequent weakness of the tissue, which turns not to be able to maintain the adherence of the distal phalanx to the hoof wall (POLLITT, 1996;LASKOSKI et al, 2010). Laminitis secondary to metabolic abnormalities differs in respect to histopathology of laminar tissue of the hoof, appearing subtle injury of the laminar structures (KARIKOSKI et al, 2014), and being detected even without clinical signs of disease in horses with PPID -Pituitary Pars Intermedia Dysfunction .…”

Efeito de anti-inflamatórios não esteroidais na apoptose de células epidermais lamelares de equinos com laminite

“…A indução da apoptose é desejável na regressão de células tumorais (Brown et al, 2001;Elder e Paraskeva, 1999), porém uma elevada ocorrência de apoptose torna-se prejudicial e está implicada em lesões degenerativas neurológicas (Tripathy e Grammas, 2009) artrose (Yoon et al, 2003) e laminite, tendo sido descrita em tecido lamelar de cavalos com laminite aguda adquirida naturalmente (Faleiros et al, 2004). Laskoski et al (2010) não observaram diferenças nas taxas de apoptose entre animais tratados com hidrocortisona e animais do grupo controle. Porém, o efeito dos AINEs sobre a apoptose em tecido lamelar ainda não é conhecido.…”