Histomorfometria e histoquímica dos ovários, tubas e útero de ratas hipotireóideas em metaestro-diestro

Abstract

RESUMOA foliculogênese ovariana foi estudada em ratas adultas Wistar, hipotireóideas na fase de metaestrodiestro. O hipotireoidismo foi induzido pela administração oral e diária de propiltiouracil (1mg/animal). As ratas eutireóideas receberam placebo. Após 120 dias de tratamento, foi colhido o plasma para dosagem de tiroxina livre, progesterona e estradiol após o que foram sacrificadas para colheita dos ovários, tubas e útero, para avaliação histomorfométrica e histoquímica. O hipotireoidismo reduziu significativamente o peso dos ovários e o número de folículos secundários e terciários e de corpos lúteos sem, no entanto, alterar a porcentagem de folículos atrésicos e o número de folículos primários e pré-ovulatórios. As células da granulosa dos folículos secundários das ratas hipotireóideas apresentavam núcleo pequeno com significativa redução do número de regiões organizadoras de nucléolo (NORs). Essas mudanças não alteraram os valores periféricos de estradiol e de progesterona. Houve redução significativa da espessura do endométrio, do número de glândulas endometriais e da altura do epitélio do infundíbulo.Palavras-chave: rata, hipotireoidismo, ovário, tuba, útero, NORs ABSTRACT Ovarian folicullogenesis was studied in adult

Neurotransmitters Level in Hypothyroid Male Albino Rats after Isotretinoin Treatment

“…There is a significant decrease in body weight of hypothyroid rat model used Table 6 compared to control group which coincide with the results of Schneider and Golden (1987), Dratman et al (1987) and Silva et al (2004). In thyroid hypofunction, an increase of protein catabolism occurred, with consequent reduction of muscle mass; synthesis of proteins, vitamins, growth factors; reduction of intestinal absorption of carbohydrates; in addition to osteopenia (Allain et al, 1995).…”

“…The hypothyroid rat model (Serakides et al, 2002;Silva et al, 2004) in this study presented by significant decrease in serum fT4 and fT3 and highly significant increase of TSH level throughout the experimental period (Table 1).…”

“…Induction of hypothyroidism by Propylthiouracil (PIU) 5 mg kgG 1 b.wt. oral daily dose for 30 days (Serakides et al, 2002;Silva et al, 2004). The development of hypothyroid is considered zero time.…”

Model of induction of thyroid dysfunctions in adult female mice

“…Animals of the hypothyroid group consumed a mean of 2.20mg of PTU/animal/day and those from the hyperthyroid group ingested a mean of 20.49 g of Lthyroxin/animal/day (Table 2). In rats, 1mg of PTU/kg is the recommended dose to induce hypothyroidism (Serakides et al, 2002;Silva et al, 2004). In a pilot experiment, out this dose yielded no significantly changes in the morphology of the gland and may be enough to induce hypothyroidism in mice in a short term.…”

“…Experimental studies associated with thyroid dysfunctions and changes in the metabolism and body development are based on the suppression of hormone production (McCardle et al, 1998;Ferreira et al, 2003;Khotimchenko e Sergushchenko, 2003;Silva et al, 2004) or thyroxin administration in high doses promoting an iatrogenic hyperthyroidism status (Kobayashi et al, 2000;Serakides et al, 2002;2005). However, most studies recommend the use of traumatic methods and protocols, as for hormone dosage or the induction methodology using rats as animal model.…”