Macro- and microstructural organization of the rabbit's celiac-mesenteric ganglion complex (Oryctolagus cuniculus)

The macro- and microstructures of the rabbit celiac-mesenteric ganglion complex are described in 20 young animals. We found ten celiac ganglia, twenty-seven cranial mesenteric ganglia and eleven celiac-mesenteric ganglia. The celiac ganglia had a rectangular shape in nine cases (90%) and a circular one in one case (10%). The cranial mesenteric ganglia presented triangular (66.7%), rectangular (11.1%), L-shape (18.5%) and semilunar (3.7%) arrangements. The celiac-mesenteric ganglia were organized in three patterns: a single left celiac-mesenteric ganglion having a caudal portion (72.7%); celiac-mesenteric ganglia without a caudal portion (18.2%) and a single celiac-mesenteric ganglion with two portions: left and right (9.1%).The microstructure was investigated in nine celiac-mesenteric ganglia. The results showed that the celiac-mesenteric ganglion is actually a ganglion complex constituted of an agglomerate of ganglionic units separated by nerve fibers, capillaries and septa of connective tissue. Using the semi-thin section method we described the cellular organization of the celiac-mesenteric ganglion complex. Inside of each ganglionic unit, there were various cell types: principal ganglion neurons (PGN), glial cells (satellite cells) and SIF cells (small intensely fluorescent cells or small granular cells), which are the cytologic basis for each ganglionic unit of the rabbit's celiac-mesenteric ganglion complex.

Effect of selective β-adrenoceptor blockade and surgical resection of the celiac-superior mesenteric ganglion complex on delayed liquid gastric emptying induced by dipyrone, 4-aminoantipyrine, and antipyrine in rats

There is evidence for participation of peripheral β-adrenoceptors in delayed liquid gastric emptying (GE) induced in rats by dipyrone (Dp), 4-aminoantipyrine (AA), and antipyrine (At). The present study aimed to determine whether β-adrenoceptors are involved in delayed GE induced by phenylpyrazole derivatives and the role of the prevertebral sympathetic nervous system in this condition. Male Wistar rats weighing 220-280 g were used in the study. In the first experiment rats were intravenously pretreated with vehicle (V), atenolol 30 mg/kg (ATE, β1-adrenergic antagonist), or butoxamine 25 mg/kg (BUT, β2-adrenergic antagonist). In the second experiment, rats were pretreated with V or SR59230A 2 mg/kg (SRA, β3-adrenergic antagonist). In the third experiment, rats were subjected to surgical resection of the celiac-superior mesenteric ganglion complex or to sham surgery. The groups were intravenously treated with saline (S), 240 µmol/kg Dp, AA, or At, 15 min after pretreatment with the antagonists or V and nine days after surgery. GE was determined 10 min later by measuring the percentage of gastric retention (%GR) of saline labeled with phenol red 10 min after gavage. The %GR (means±SE, n=6) values indicated that BUT abolished the effect of Dp (BUT+Dp vs V+Dp: 35.0%±5.1% vs 56.4%±2.7%) and At (BUT+At vs V+At: 33.5%±4.7% vs 52.9%±2.6%) on GE, and significantly reduced (P<0.05) the effect of AA (BUT+AA vs V+AA: 48.0%±5.0% vs 65.2%±3.8%). ATE, SRA, and sympathectomy did not modify the effects of treatments. These results suggest that β2-adrenoceptor activation occurred in delayed liquid gastric emptying induced by the phenylpyrazole derivatives dipyrone, 4-aminoantipyrine, and antipyrine. Additionally, the released neurotransmitter did not originate in the celiac-superior mesenteric ganglion complex.

Study on Cranial and Caudal Mesenteric Arteries in Opossum (Didelphis albiventris)

The objective of this study is to describe the cranial and caudal mesenteric arteries in 10 opossuns after Neoprene latex injection. The cranial mesenteric artery arises from the abdominal aorta, caudally to the celiac trunk, originating the caudal duodenal pancreatic artery, middle and right colic, jejunal and ileocecocolic arteries. The caudal mesenteric artery arises from the aorta, cranially to the external iliac arteries, originating the cranial rectal and left colic arteries.

The Developing Left Superior Cervical Ganglion of Pacas (Agouti Paca)

In this study the main question investigated was the number and size of both binucleate and mononucleate superior cervical ganglion (SCG) neurons and, whether post-natal development would affect these parameters. Twenty left SCGs from 20 male pacas were used. Four different ages were investigated, that is newborn (4 days), young (45 days), adult (2 years), and aged animals (7 years). By using design-based stereo-logical methods, that is the Cavalieri principle and a physical disector combined with serial sectioning, the total volume of ganglion and total number of mononucleate and binucleate neurons were estimated. Furthermore, the mean perikaryal (somal) volume of mononucleate and binucleate neurons was estimated using the vertical nucleator. The main findings of this study were a 154% increase in the SCG volume, a 95% increase in the total number of mononucleate SCG neurons and a 50% increase in the total volume of SCG neurons. In conclusion, apart from neuron number, different adaptive mechanisms may coexist in the autonomic nervous system to guarantee a functional homeostasis during ageing, which is not always associated with neuron losses. Anat Rec, 292:966-975, 2009. (C) 2009 Wiley-Liss, Inc.

Diabetes mellitus-related morphoquantitative changes in the celiac ganglion neurons of the dog

Diabetes mellitus is the most common endocrine disturbance of domestic carnivores and can cause autonomic neurological disorders, although these are still poorly understood in veterinary medicine. There is little information available on the quantitative adaptation mechanisms of the sympathetic ganglia during diabetes mellitus in domestic mammals. By combining morphometric methods and NADPH-diaphorase staining (as a possible marker for nitric oxide producing neurons), type I diabetes mellitus-related morphoquantitative changes were investigated in the celiac ganglion neurons in dogs. Twelve left celiac ganglia from adult female German shepherd dogs were examined: six ganglia were from non-diabetic and six from diabetic subjects. Consistent hypertrophy of the ganglia was noted in diabetic animals with increase of 55% in length, 53% in width, and 61.5% in thickness. The ordinary microstructure of the ganglia was modified leading to an uneven distribution of the ganglionic units and a more evident distribution of axon fascicles. In contrast to non-diabetic dogs, there was a lack of NADPH-diaphorase perikarial labelling in the celiac ganglion neurons of diabetic animals. The morphometric study showed that both the neuronal and nuclear sizes were significantly larger in diabetic dogs (1.3 and 1.39 times, respectively). The profile density and area fraction of NADPH-diaphorase-reactive celiac ganglion neurons were significantly larger (1.35 and 1.48 times, respectively) in non-diabetic dogs compared to NADPH-diaphorase-non-reactive celiac ganglion neurons in diabetic dogs. Although this study suggests that diabetic neuropathy is associated with neuronal hypertrophy, controversy remains over the possibility of ongoing neuronal loss and the functional interrelationship between them. It is unclear whether neuronal hypertrophy could be a compensation mechanism for a putative neuronal loss during the diabetes mellitus. (C) 2007 Elsevier Ltd. All rights reserved.

Origem das artérias celíaca e mesentérica cranial em bubalinos (Bubalus bubalis, L. 1758)

Com o intuito de conhecer melhor o sistema arterial nesta espécie, descrevemos a origem das artérias celíaca e mesentérica cranial dos bubalinos. Utilizamos 30 fetos e 1 animal adulto. Os fetos variavam de 4 a 8 meses de idade e tiveram seus vasos injetados com solução de látex - Neoprene, tiveram seus vasos dissecados, e um animal adulto, que teve seus vasos dissecados no local de abate. Observamos que as artérias celíaca e mesentérica cranial originavam-se da porção torácica da aorta em todos os casos, estando isoladas em 90,33% deles e em tronco comum (tronco celíaco mesentérico) em 9,67% dos casos.

Os arranjos configurados pelas artérias mesentéricas cranial e caudal no pato doméstico (Cairina moshata)

Mediante esta pesquisa, estudamos os arranjos configurados pelas artérias mesentéricas cranial e caudal em 30 patos domésticos, 20 machos e 10 fêmeas. Foi realizada a injeção de látex 650 corado no sistema arterial e a seguir as peças foram fixadas em solução aquosa de formol a 10% para posteriormente serem dissecadas. A artéria mesentérica cranial nasce como um vaso ímpar da aorta descendente à altura da 6ª e 7ª costelas, em situação imediatamente caudal à artéria celíaca. Junto à junção íleo-ceco-cólica, subdivide-se basicamente em 3 ramos: o primeiro emite um vaso destinado ao colonreto, anastomosando-se com a artéria mesentérica caudal. O segundo ramo se comporta como tronco para as artérias jejunais, sendo que o número delas varia de 8 a 20. Finalmente, o terceiro ramo destina-se às porções principal e final do ceco direito e também ao íleo, vascularizando-os. No atinente ao comportamento da artéria mesentérica caudal, observamos que ela nasce como um vaso ímpar, a partir da aorta descendente, à altura das porções caudais dos rins. A artéria mesentérica caudal, na totalidade das peças examinadas, divide-se em 2 ramos: um cranial, que, por sua vez, emite 2 vasos menores para o mesorreto e um ramo caudal, que vasculariza a porção terminal do reto, bolsa cloacal e a cloaca.

Modelo de suprimento sanguíneo do intestino grosso do tamanduá bandeira (Myrmecophaga tridactyla)

Em seis animais adultos Myrmecophaga tridactyla estudou-se o modelo de suprimento sanguíneo do intestino grosso, que é dependente das artérias mesentérica cranial (AMCr) e caudal (AMC). Os espécimes coletados conforme as normas do IBAMA (Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis) foram perfundidos com água (40 C), injetados com látex corado, fixados em formol e conservados em solução alcoólica (50%). O mesocólon está disposto na linha sagital mediana e fixa o intestino grosso à parede dorsal do abdome. Derivaram da AMC: a artéria retal cranial, sete a 14 artérias cólicas e uma ou duas artérias ileocólicas, que apresentaram anastomoses de irrigação com a AMCr. A AMC finaliza-se na borda mesocólica das alças intestinais, emitindo ramos cólicos retos a partir das arcadas justacólicas, que penetram na intimidade da musculatura longitudinal. Ao longo do trajeto da AMC foram observadas ilhas arteriais, e a região ileocólica apresentou maior densidade vascular.

Stereological and allometric studies on neurons and axo-dendritic synapses in the superior cervical ganglia of rats, capybaras and horses

The superior cervical ganglion (SCG) in mammals varies in structure according to developmental age, body size, gender, lateral asymmetry, the size and nuclear content of neurons and the complexity and synaptic coverage of their dendritic trees. In small and medium-sized mammals, neuron number and size increase from birth to adulthood and, in phylogenetic studies, vary with body size. However, recent studies on larger animals suggest that body weight does not, in general, accurately predict neuron number. We have applied design-based stereological tools at the light-microscopic level to assess the volumetric composition of ganglia and to estimate the numbers and sizes of neurons in SCGs from rats, capybaras and horses. Using transmission electron microscopy, we have obtained design-based estimates of the surface coverage of dendrites by postsynaptic apposition zones and model-based estimates of the numbers and sizes of synaptophysin-labelled axo-dendritic synaptic disks. Linear regression analysis of log-transformed data has been undertaken in order to establish the nature of the relationships between numbers and SCG volume (V(scg)). For SCGs (five per species), the allometric relationship for neuron number (N) is N=35,067xV (scg) (0.781) and that for synapses is N=20,095,000xV (scg) (1.328) , the former being a good predictor and the latter a poor predictor of synapse number. Our findings thus reveal the nature of SCG growth in terms of its main ingredients (neurons, neuropil, blood vessels) and show that larger mammals have SCG neurons exhibiting more complex arborizations and greater numbers of axo-dendritic synapses.

Hypertrophy and neuron loss: structural changes in sheep SCG induced by unilateral sympathectomy

Recently, superior cervical ganglionectomy has been performed to investigate a variety of scientific topics from regulation of intraocular pressure to suppression of lingual tumour growth. Despite these recent advances in our understanding of the functional mechanisms underlying superior cervical ganglion (SCG) growth and development after surgical ablation, there still exists a need for information concerning the quantitative nature of the relationships between the removed SCG and its remaining contralateral ganglion and between the remaining SCG and its modified innervation territory. To this end, using design-based stereological methods, we have investigated the structural changes induced by unilateral ganglionectomy in sheep at three distinct timepoints (2, 7 and 12 weeks) after surgery. The effects of time, and lateral (left-right) differences, were examined by two-way analyses of variance and paired t-tests. Following removal of the left SCG, the main findings were: (i) the remaining right SCG was bigger at shorter survival times, i.e. 74% at 2 weeks, 55% at 7 weeks and no increase by 12 weeks, (ii) by 7 weeks after surgery, the right SCG contained fewer neurons (no decrease at 2 weeks, 6% fewer by 7 weeks and 17% fewer by 12 weeks) and (iii) by 7 weeks, right SCG neurons were also larger and the magnitude of this increase grew substantially with time (no rise at 2 weeks, 77% by 7 weeks and 215% by 12 weeks). Interaction effects between time and ganglionectomy-induced changes were significant for SCG volume and mean perikaryal volume. These findings show that unilateral superior cervical ganglionectomy has profound effects on the contralateral ganglion. For future investigations, it would be interesting to examine the interaction between SCGs and their innervation targets after ganglionectomy. Is the ganglionectomy-induced imbalance between the sizes of innervation territories the milieu in which morphoquantitative changes, particularly changes in perikaryal volume and neuron number, occur? Mechanistically, how would those changes arise? Are there any grounds for believing in a ganglionectomy-triggered SCG cross-innervation and neuroplasticity? (C) 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

Estudo do sistema portal hepático no pato doméstico (Cairina moshata)

Estudou-se o comportamento do sistema portal hepático em 30 patos domésticos, adultos, machos e fêmeas. O sistema apresenta-se constituído por duas veias portais hepáticas: direita e esquerda. A veia portal hepática esquerda é formada por veias gástricas esquerdas (em número de 1 a 2), veias da margem ventral do ventrículo, veia pilórica e veia proventricular caudal. A veia portal hepática direita é formada pela veia mesentérica caudal, veia mesentérica cranial, veia proventrículo-esplênica e veia gastropancreaticoduodenal. A veia mesentérica caudal recebe tributárias do mesorreto, cloaca e junção ileocecocólica. A veia mesentérica cranial recebe tributárias jejunais (em número de 12 a 21) e se anastomosa com a veia mesentérica caudal, formando a veia mesentérica comum. A veia pancreaticoduodenal recebe duas veias gástricas direitas, constituindo assim a veia gastropancreaticoduodenal. A veia proventrículo-esplênica é formada pelas veias proventriculares dorsal e direita e pelas veias esplênicas.

Fertility of rat epididymal sperm after chemically and surgically induced sympathectomy

Guanethidine, a chemical that selectively blocks sympathetic noradrenergic neurons, was used to investigate the role of sympathetic innervation in the fertility of rat epididymal sperm, using both natural mating and in utero insemination protocols. This animal model correlates, at least in part, with spinal cord injury (SCI) in men. Adult male rats were treated daily by i.p. injections, for 21 or 42 days, with 0 or 6.25 mg/kg guanethidine. To compare the effects of guanethidine-induced sympathectomy with those following surgically induced sympathectomy, the inferior mesenteric ganglion and the proximal hypogastric nerves were removed in another group of rats. Both chemically and surgically induced sympathectomy increased the weight of the epididymis and seminal vesicles/coagulating glands as well as the number and the transit time of cauda epididymal sperm. Neither serum testosterone levels nor LH was affected by treatment with guanethidine. Using natural mating, no litters were produced by guanethidine-treated rats. Chemically denervated rats failed to produce copulatory plugs or ejaculate into the uterus. However, distal cauda epididymal sperm from chemically or surgically denervated rats displayed normal fertilization ability (80%) using in utero inseminations. In addition, the sperm of denervated rats did not show abnormal sperm chromatin structure using an assay that detects DNA damage. We conclude that sympathectomy delays the transit of sperm through the cauda epididymidis and produces ejaculatory dysfunction but does not compromise sperm quality in the distal cauda epididymidis. Moreover, these data provide compelling evidence that there is no association between the prolonged transit time of sperm within the epididymis, i.e., pre-ejaculatory sperm aging, and the fertility of those sperm, which has important implications for artificial insemination using sperm from men with SCI.

Configuração do sistema venoso portal na cutia (Dasyprocta aguti, RODENTIA)

O estudo da veia porta quanto aos vasos confluentes para sua formação e suas tributárias foi efetuado em 10 cutias (Dasyprocta aguti), adultas (3 fêmeas e 7 machos), nas quais o sistema desta veia foi injetado com látex corado, sendo a seguir fixadas em formol a 10% e dissecadas. Verificou-se que o tronco da veia porta origina-se sempre pela confluência de duas raízes, sendo representadas em 90% dos casos, pela veia lienal e pelo tronco mesentérico comum, constituído pelas veias mesentéricas cranial e caudal e, em 10%, pela veia lienal e pela veia mesentérica cranial. O tronco da veia porta recebe como tributárias a veia pancreaticoduodenal cranial (100%), a veia gástrica direita (90%) e, ainda, a veia gastroepiplóica direita (40%).

Gross anatomy of the portal vein and its tributaries in the opossum (Didelphis albiventris)

The gross anatomy of the portal vein (V. portae) and its tributaries was studied through anatomical methods, i.e. dissection, corrosion and diaphanization, in 45 opossums (Didelphis albiventris). In all animals the portal vein was formed by the junction of the cranial mesenteric, caudal mesenteric and lienal veins (V. mesenterica cranialis, V. mesenterica caudalis and V. lienalis, respectively). Many collateral tributaries were observed running into the portal venous trunk.

Considerations sur la ramification de L'aorte abdominale du hamster (Mesocricetus Auratus)

The disposition of the abdominal aorta branching in Mesocricetus auratus is described, establishing variation groups with relation to the celiac, cranial mesenteric, renal, genital and caudal mesenteric arteries. Sixty animals (30 males and 30 females) of different ages and weights, were anesthetized with chloroform, injected with contrasting substance in the abdominal aorta (50 animals with Neoprene latex and 10 with a radioopaque mass), after which they were dissected with the help of a stereoscopic microscope. The animals with radioopaque masses were radiographed in comparison with the other animals. The results are expressed in relative percentage figures and compared with other mammalian arterial dispositions.