Effect of maternal protein deprivation on morphological and quantitative aspects of the myenteric plexus neurons of proximal colon in rats

Abstract

-We have studied the morphological an d quantitative aspects of the myenteric plexus neurons of the proximal colon in rats (Rattus norvegicus of Wistar strain) submitted to a protein deprivation during prenatal and lactatio n periods . Twent y pregnan t dam s wer e divide d i n fou r group s labele d accordin g t o th e kin d o f nourishment they were given: Group NN, normal diet; Group DN, low protein diet during prenatal period, and normal diet during lactation period; Group ND, normal diet during prenatal period, and low protein diet during lactation period ; Group DD, low protein die t during prenatal an d lactation periods. Histological analyses wer e developed wit h proxima l colo n segment s usin g th e haematoxyli n an d eosi n stainin g method . Membran e preparations were stained by Giemsa's method. The statistical analysis has demonstrated no significant differenc e among the mean s o f neuron s foun d i n th e fou r studie d groups . I t was notice d tha t th e animal s unde r protei n deprivation durin g prenata l an d lactatio n period s presente d greate r quantit y o f larg e an d strongl y basophili c myenteric neurons. This suggest s that neurons have accumulated protei n i n the cytoplasm .KEY WORDS: enteric neurons, myenteric plexus, proteic deprivation, proximal colon, gestation, lactation.Reviewing the available data, it was found that many authors direct their studies to the effec t of undernutrition o n the central nervous system 3,16,18,19 . Fe w were the studies foun d relatin g t o the effects of undernutrition on the peripheral nervous system, and fewer were the studies found concerning

Effects of pre- and postnatal protein deprivation and postnatal refeeding on myenteric neurons of the rat large intestine: a quantitative morphological study

“…The neuron numbers in the myenteric plexus of the large intestine were not statistically different between normally fed and undernourished groups at 21 days, and between normally fed, undernourished groups, and undernourished and refed groups at 42 days. The results agree with Leite-Mello et al (1997), who did not find a statistical difference in the neuron numbers in the proximal portion of the colon between undernourished and nourished rats. In contrast, Santer and Conboy (1990) showed that prenatal undernutrition, by providing pregnant mothers with half the amount of food they would normally consume, decreased enteric neuron numbers in the jejunum by 27%, and that this decrease was measurable at 140 days postnatal, despite the animals being fed a normal diet.…”

Effects of combined pre- and post-natal protein deprivation on the myenteric plexus of the esophagus of weanling rats: A histochemical, quantitative and ultrastructural study

“…The quantitative data of NADH-reactive neurons resembles the findings on the colon of proteindeprived young animals [3] , in that the total estimated number of neurons in the esophagus was not statistically different between N and D groups. This is also in line with the data for the proximal portion of the colon, where another group could not demonstrate a difference in neuronal number between undernourished and nourished rats [37] .…”

Morphoquantitative characteristics of myenteric neurons of the terminal segment of the intestine of Cyprinus carpio (Linnaeus, 1758) (Osteichthyes, Cyprinidae)

“…Agreeing with Leite-Mello et al (1997), we observed that peripheral nuclei predominate on the large and medium neurons. Among small neurons, nuclei show peripheral and central positions.…”

“…In our samples, small and medium neurons predominated, independently of their shape, in contrast with the observations by Leite-Mello et al (1997) on the colon of rats, where large and medium neurons are the most abundant. According to Gabella (1971), small neurons would represent the intrinsic portion of the myenteric plexus responsible for motor activity and are found in small numbers on the rectum of rats.…”

“…Gabella (1990) commented about the plasticity of form and structure of enteric ganglia in relation to diameter and length of the intestine. Recent research in rat intestine showed the presence of small, medium and large neurons with varied cytoplasmic basophily and peripheral nucleus (Leite-Mello et al, 1997). Quantitative studies revealed the presence of 100 to 200 neurons/cm 2 on the intestine of Salmo trutta without the formation of true ganglia (Burnstock, 1959).…”