Morphological characteristics of ovarian development of two Nile tilapia (Oreochromis niloticus) strains in mixed-culture systems / Características morfológicas do desenvolvimento ovariano de duas linhagens de tilápia-do-nilo (Oreochromis niloticus), em sistemas de cultivo misto

This study was carried out to morphologically characterize and classify the stages of gonad development in different Nile tilapia strains (Oreochromis niloticus). Eighty-four and ninety-two ovaries from Bouaké and Chitralada strains, respectively, were evaluated at different ovarian developmental phases: initial (104 days of culture), intermediate (152 days of culture), and the final (279 days of culture). The ovaries were microscopically evaluated and submitted to histological processing and hematoxylin-eosin staining to determine their characteristics and be classified. No morphological differences in ovaries between strains were observed during the initial phase (stage A - immature). During the intermediate growing phase, higher gonad development was observed for Chitralada strain (stage B - maturation) in comparison with Bouaké strain (stage A - immature). During the final growing phase, no differences between strains were observed for morphological characteristics (stage C - mature). Despite the similarities in reproductive behavior of the Bouaké and Chitralada females at the end of the final growing phase (gain weight phase), differences for macroscopic and microscopic aspects and oocytes during the initial and intermediate growing phases of the strains were observed.

Este trabalho teve como objetivo caracterizar morfologicamente e classificar os estádios de desenvolvimento gonadal de tilápias do Nilo (Oreochromis niloticus) de linhagens distintas. Foram avaliados 84 ovários da linhagem Bouaké e 92 da linhagem Chitralada, em diferentes fases de desenvolvimento: inicial (imatura - 104 dias de cultivo), intermediária (crescimento - 152 dias de cultivo) e final (ganho de peso - 279 dias de cultivo). Os ovários foram analisados macroscopicamente e submetidos a procedimento histológico, corados com hematoxilina-eosina, para determinação das características microscópicas e subsequente classificação. Não foram observadas diferenças morfológicas nos ovários entre as linhagens na fase inicial (estádio A - imaturo). Na fase intermediária, os ovários revelaram diferenças morfológicas, evidenciando maior desenvolvimento gonadal para a linhagem Chitralada, (estádio B - maturação) em relação à Bouaké (estádio A). Na fase final (ganho de peso) os ovários não apresentaram diferenças morfológicas entre as linhagens (estádio C - maduro). Apesar de semelhanças no comportamento reprodutivo das fêmeas das linhagens Bouaké e Chitralada, na fase final (ganho de peso), diferenças, em relação à classificação da fase intermediária nos aspectos macroscópicos e microscópicos e diâmetro dos ovócitos, foram observadas.

Morphological characteristics of ovarian development of two Nile tilapia (Oreochromis niloticus) strains in mixed-culture systems / Características morfológicas do desenvolvimento ovariano de duas linhagens de tilápia-do-nilo (Oreochromis niloticus), em sistemas de cultivo misto

This study was carried out to morphologically characterize and classify the stages of gonad development in different Nile tilapia strains (Oreochromis niloticus). Eighty-four and ninety-two ovaries from Bouaké and Chitralada strains, respectively, were evaluated at different ovarian developmental phases: initial (104 days of culture), intermediate (152 days of culture), and the final (279 days of culture). The ovaries were microscopically evaluated and submitted to histological processing and hematoxylin-eosin staining to determine their characteristics and be classified. No morphological differences in ovaries between strains were observed during the initial phase (stage A - immature). During the intermediate growing phase, higher gonad development was observed for Chitralada strain (stage B - maturation) in comparison with Bouaké strain (stage A - immature). During the final growing phase, no differences between strains were observed for morphological characteristics (stage C - mature). Despite the similarities in reproductive behavior of the Bouaké and Chitralada females at the end of the final growing phase (gain weight phase), differences for macroscopic and microscopic aspects and oocytes during the initial and intermediate growing phases of the strains were observed.(AU)

Este trabalho teve como objetivo caracterizar morfologicamente e classificar os estádios de desenvolvimento gonadal de tilápias do Nilo (Oreochromis niloticus) de linhagens distintas. Foram avaliados 84 ovários da linhagem Bouaké e 92 da linhagem Chitralada, em diferentes fases de desenvolvimento: inicial (imatura - 104 dias de cultivo), intermediária (crescimento - 152 dias de cultivo) e final (ganho de peso - 279 dias de cultivo). Os ovários foram analisados macroscopicamente e submetidos a procedimento histológico, corados com hematoxilina-eosina, para determinação das características microscópicas e subsequente classificação. Não foram observadas diferenças morfológicas nos ovários entre as linhagens na fase inicial (estádio A - imaturo). Na fase intermediária, os ovários revelaram diferenças morfológicas, evidenciando maior desenvolvimento gonadal para a linhagem Chitralada, (estádio B - maturação) em relação à Bouaké (estádio A). Na fase final (ganho de peso) os ovários não apresentaram diferenças morfológicas entre as linhagens (estádio C - maduro). Apesar de semelhanças no comportamento reprodutivo das fêmeas das linhagens Bouaké e Chitralada, na fase final (ganho de peso), diferenças, em relação à classificação da fase intermediária nos aspectos macroscópicos e microscópicos e diâmetro dos ovócitos, foram observadas.(AU)

Effect of age on the myosin-V immunoreactive myenteric neurons of rats ileum

Alterations in the gastrointestinal neuromuscular function related to age have been demonstrated in human and animal models. This study analyzes the effects of the aging process on the area of the neuronal cell bodies of the myenteric plexus in the antimesenteric and intermediate regions of the ileal circumference of Wistar, 12 month-old in comparison 3 month-old animals. The ileum was removed and whole-mount preparations immunostained by the antibody anti-myosin-V were processed. The morphometric analyses were performed using a computerized image analysis system, with a subsequent distribution of neurons by size in intervals of 100 micro2. The cellular body morphometry revealed a significant increase in the size of the myosin-V- immunoreactive myenteric neurons from 12 month-old animals when compared with 3 month –old animals. However, significant differences between the regions were not observed; these observations were not age-dependent. The implications of these results in relation to the increase of the body weight, size of the small intestine, general organization of the myenteric plexus, staining method of neurons and the possible factors involved in the regulation and/or control of the volume of neronal cells due to aging, are discussed.

Effect of age on the myosin-V immunoreactive myenteric neurons of rats ileum

Alterations in the gastrointestinal neuromuscular function related to age have been demonstrated in human and animal models. This study analyzes the effects of the aging process on the area of the neuronal cell bodies of the myenteric plexus in the antimesenteric and intermediate regions of the ileal circumference of Wistar, 12 month-old in comparison 3 month-old animals. The ileum was removed and whole-mount preparations immunostained by the antibody anti-myosin-V were processed. The morphometric analyses were performed using a computerized image analysis system, with a subsequent distribution of neurons by size in intervals of 100 micro2. The cellular body morphometry revealed a significant increase in the size of the myosin-V- immunoreactive myenteric neurons from 12 month-old animals when compared with 3 month ¹old animals. However, significant differences between the regions were not observed; these observations were not age-dependent. The implications of these results in relation to the increase of the body weight, size of the small intestine, general organization of the myenteric plexus, staining method of neurons and the possible factors involved in the regulation and/or control of the volume of neronal cells due to aging, are discussed.(AU)

Supplementation of glutamine and vitamin E on the morphometry of the intestinal mucosa in broiler chickens.

The objective of this experiment was to evaluate the influence of Gln and vitamin E (VE) supplementation in the diet of broiler chickens (Cobb-Vantress) on the morphometry of the intestinal mucosa. The design was completely randomized in a 2 x 3 (VE x periods of administering Gln) factorial arrangement. The levels of VE used were 10 and 500 mg/kg of diet and 3 periods of administering (1%) Gln-supplemented starter diet (for the first 7 or 14 d of life or for no added Gln), totaling 6 treatments with 5 replicates of 50 birds per experimental unit. In the growth period (d 22 to 41 posthatch), the treatments consisted only in the respective levels of VE. On d 7, 14, 21, and 41 posthatch, 2 birds per replicate were killed, and samples of the duodenum, jejunum, and ileum were subsequently removed, fixed in Bouin solution, and later embedded in paraffin and stained with hematoxylin-eosin. The parameters analyzed were villus height and crypt depth. An ANOVA was applied to the obtained data, and the means were compared using Tukey's test (5% significance level). Greater development was observed in the duodenum, followed by the jejunum and ileum. On 41 d of life, diets with 10 mg of VE/kg supplemented with Gln (for the first 7 d of life) provided better development of the intestinal mucosa in broiler chickens.

Morphometric and quantitative evaluation of the NADH-diaphorase positive myenteric neurons of the jejunum of streptozotocin-diabetic rats supplemented with acetyl-L-carnitine.

Summary In this study we investigated the effect of the acetyl-L-carnitine (ALC) supplementation on the myenteric neurons of the jejunum of rats made diabetic at the age of 105 days by streptozotocin (35 mg/kg body weight). Four groups were used: non-diabetic (C), non-diabetic supplemented with ALC (CC), diabetic (D), diabetic supplemented with ALC (DC). After 15 weeks of diabetes induction the blood was collected by cardiac puncture to evaluate glycaemia and glycated haemoglobin. Next the animals were killed and the jejunum was collected and subjected to whole-mount preparation to evidence the myenteric neurons through the histochemical technique of the NADH-diaphorase. The neuronal counts were made in 80 microscopic fields, in tissue samples of five animals of each group. The profiles of the cell bodies of 1000 neurons per group were analysed. Diabetes induced a significant increase in the area of the cell body and decrease in the number of NADH-diaphorase positive myoenteric neurons. ALC suplementation to the diabetic group promoted smaller hypertrophic effects and less neuronal loss than in the myoenteric neurons of the diabetic rats, and in addition diminished the body weight decrease and reduced the fasting glycaemia.

Regional differences in the number and type of myenteric neurons of the ileum of rats: a comparison of techniques of the neuronal evidentiation.

We carried out this study with the purpose of analyzing the density of neurons of the myenteric plexus in the mesenteric, intermediate and antimesenteric regions of the ileum of rats. Whole-mounts stained with four different techniques were employed. Through countings under optic microscope in an area of 8.96 mm2 we found the following neuronal means with the techniques of Giemsa, NADH-diaphorase histochemistry, NADPH-diaphorase and acetylcholinesterase, respectively: mesenteric region 2144.40+/-161.05, 1657.80+/-88.23, 473.80+/-19.62, 905.25+/-22.40; intermediate region 1790.60+/-128.24, 1265.20+/-141.17, 371.30+/-27.84, 770.25+/-33.12; antimesenteric region 1647.0+/-76.67, 981.80+/-68.04, 298.50+/-22.75, 704.50+/-69.38. We conclude that there is a variation of neuronal density around the intestinal circumference and this fact independs on the technique used to stain the neurons, and that in a single region the neuronal density varies with the technique employed. We also call attention for the identification of the site were countings were carried out, so that the results of research in this area are not compromised.

Ultrastructural features of myenteric ganglia of adult Wistar rats (Rattus norvegicus).

The ultrastructural features of the ganglia of the myenteric plexus exhibit changes according to the animal species. These myenteric ganglia in the duodenum of adult rats of the Wistar strain were characterized ultrastructurally in this work. Those ganglia were depicted as compact structures, composed of neurones and glial cells, forming a dense neuropil surrounded by a continuous basal lamina and collagen fibrils. Glial cell bodies were smaller and apparently more frequent than neuronal cell bodies, being morphologically distinguished by nuclear features. In the neuronal extensions granular and agranular synaptic vesicles of different sizes predominate, in addition to mitochondria and myelinized profiles. Gliofilaments were not observed on the glial extensions of the rats.

Morphologic and quantitative study of the myenteric neurons of the jejunum of malnourished rats (Rattus norvegicus).

We studied the effects of maternal proteic desnutrition on the neurons of the myenteric plexus of the jejunum of rats from Rattus norvegicus species. It was used litters of female rats which received diet with normal proteic level during gestation and lactation (group NN), normal diet during gestation and hypoproteic diet during lactation (group ND); hypoproteic diet during gestation and normal diet during lactation (group DN); hypoproteic diet during both gestation and lactation (group DD). After weaning all the animals received diet of normal proteic level until the 60th day of age, when they were killed. The jejunum of the animals was subjected to whole-mount preparations stained by the method of Giemsa and used for the morphologic and quantitative analyses of the neurons of the myenteric plexus. We verified that maternal proteic malnutrition does not cause decrease on the number of myenteric neurons per unit area of jejunum in rats, but elicits mechanisms which assure that, when the animal again receives normal proteic level diet (22%) there occurs storage of proteic material on the cytoplasm of the neurons, thus rendering them larger and strongly basophylic.

Effects of maternal proteic undernutrition on the neurons of the myenteric plexus of the duodenum of rats.

The purpose of this study was to verify the effects of proteic undernutrition on the neurons of the myenteric plexus from the duodenum of Wistar rats. Twenty-four animals at the age of 60 days were divided in four groups, which were named according to the period their mothers received hypoproteic ration (8%). Some segments of duodenum were subjected to histological treatment and stained with hematoxilin-eosin and some were used for whole mount preparations stained with Giemsa. We observed small, medium-sized and large neurons grouped in ganglia of various shapes. It was concluded that the maternal proteic undernutrition does not affect the organization of the myenteric plexus and that animals submitted to undernutrition during gestation and lactation, when normally fed, show neurons with strongly basophilic cytoplasm and larger cellular bodies than those from control animals.