Vol.28-Issue 2 - 2004
Vol.28-Issue 2 - 2004
Histomorphological and quantitative immunohistochemical
changes in the rat pancreas during aging
F.L. RICCILLO, M.I. BRACAMONTE, G.M. CÓNSOLE AND C.L.A. GÓMEZ DUMM
Cátedra de Histología-Embriología “B”, Facultad Ciencias Médicas, Universidad Nacional de La Plata, Argentina.
Key words: aging, pancreas, islets, immunohistochemistry, morphometry.
ABSTRACT: Although the endocrine pancreas is the purpose of several deep investigations, morphological
data referred to the effect of aging on the gland are not homogeneous. The purpose of the current work was to
analyze the changes occurring in the pancreas of aged rats, with especial reference to the islet cell populations.
Six young (Y), old (O) and senescent (S) male Sprague-Dawley rats were used. The pancreas tails were
processed for light microscopy and studied by means of routine stains as well as by immunohistochemical
identification of insulin-, glucagon-, somatostatin-, and pancreatic polypeptide- secreting cells (Dako Envision
System, DAB as chromogen). A progressive pancreatic histoarchitecture distortion was found among the
aged animals. Even when the alterations were not uniformly observed, they appeared more evident and severe
in the S group. The S rats showed significantly increased volume density and cell density of the B cell
population, as well as larger number of islet profiles, when compared to O rats. A significant progressive
increment of adipose tissue was also evident in aged animals. No abnormal changes were detected in the non-
B cell populations of the different groups.
The quantitative changes found in aged animals suggest a possible compensatory reaction of the B cell
population in an attempt to curb the influence of diabetogenic factors mounting with advanced age.
Study of the myenteric and submucous plexuses after BAC
treatment in the intestine of rats
NILZA CRISTINA BUTTOW, MIRIAM SANTIN, LUCIANA CONCI MACEDO, ALINE CRISTINA NERES TEIXEIRA,
GISELE CAROLINE NOVAKOWSKI, TAÍSE ROBERTA BOLONHEIS ARMELIN AND KATHYA ASSMANN
Department of Morphophysiological Sciences; Universidade Estadual de Maringá; Brazil
Key words: myenteric plexus, submucous plexus, morphology, Benzalkonium chloride, denervation.
ABSTRACT: A morphological and quantitative study in the ileal and colonic myenteric and submucous
plexuses of rats after BAC denervation was performed. Four groups were employed: SI – ileum control; CBI – denervated ileum; SC – colon control; and CBC – denervated colon. We used the Myosin-V immunohistochemistry
technique to study the myenteric and submucous plexuses. In the submucous plexus of the ileum
and colon there was not a significant decrease in the number of neurons/mm2 and of ganglia/mm2. The denervation
of the myenteric plexus in the group CBI was 44.7% and in the group CBC, 68.3%. In the myenteric
plexus there was also a significant decrease in the number of ganglia/mm2 (13.8% in group CBI and 52.14%
in group CBC) and in the number of neurons/ganglion (33.9% in group CBI and 39.6% in group CBC). The
morphological analyses showed that there was an alteration in the shape of the ganglia of the ileal and colonic
myenteric plexus. The area of the cell bodies had a significant increase both in the myenteric and the submucous
plexus in groups CBI and CBC. These data demonstrate that the BAC treatment causes morphologic and
quantitative changes in the myenteric plexus and quantitative changes in the cell body area of the submucous
plexus.
Probiotics enhance the recovery of gut atrophy in experimental
malnutrition
DIANA B. DOCK*, JOSÉ E. AGUILAR-NASCIMENTO** AND MARCIA Q. LATORRACA*
* Department of Nutrition & Dietetics, Nursing and Nutrition School, The Federal University of Mato Grosso, Brazil
** Department of Surgery, The Federal University of Mato Grosso, Brazil.
Key words: probiotics, malnutrition, small bowel, colon, mucosa
ABSTRACT: AIM: The aim of this study was to evaluate the effect of probiotics on the recovery of the bowel atrophy induced by malnutrition in rats. METHODS: Twenty-and-six Wistar rats (200-250g) were fed with either a normoproteic (sham group, n=6) or a free-protein diet (n=20) during 12 days. Twelve malnourished rats were randomized to recover during 15 days with either a hydrolyzed diet (control group, n=6) or the same diet enriched with probiotics (Streptococcus thermophilus and Lactobacillus helveticus; probiotic group, n=6). RESULTS: Probiotic group showed similar gain of body, liver and bowel weight than controls. At the jejunum, both the villus height (383±49 vs. 321±46mm; p=0.04) and crypt depth (157±31 vs. 125±10mm; p=0.04) were greater in probiotic group than in controls. The crypt depth at the cecum (214±22 vs. 169±43 mm; p=0.05) and the wall width at both the cecum (410±18 vs. 340±61 mm; p=0.02) and sigmoid (479±130 vs. 330±62 mm; p=0.03) were higher in probiotic than in control group. CONCLUSION: Streptococcus thermophilus and Lactobacillus helveticus enhance the recovery of gut atrophy induced by malnutrition. Probiotics can be useful as oral adjuvants during the recovery of malnutrition.
Fine-structural details of the photoreceptor membranes in the
ocellus of the scale-insect parasite Centrodora sp. (Hymenoptera;
Aphenelidae): A case of gene transfer between host and parasite?
MOUYU YANG1 AND V.BENNO MEYER-ROCHOW1,2
1. School of Engineering and Science, International University Bremen, D-28725 Bremen, Germany.
2. Department of Biology, University of Oulu, P.O.Box 3000, SF-90014 Oulu, Finland.
Key words: Insect retina, eye, ocellus, parasitoid, visual membrane.
ABSTRACT: Only one insect (the scale insect Eriococcus sp.) is known, in which photoreceptive lamellae appear to have replaced the usual arthropod rhabdom microvilli. We are now reporting the presence of photoreceptive membranes, which also appear to resemble lamellae rather than microvilli, but they are in the ocellus of the tiny wasp Centrodora sp., which parasitizes scale insect eggs. The apparently optically homogenous lens of the Centrodora ocellus measures approximately 10 µm in diameter and, thus, operates at the limits of diffraction. We calculated that the lens is capable of focusing a parallel bundle of rays on the retina of the ocellus.
Intrahost distribution and trasmission of a new species of
cyclopoid copepod endosymbiotic to a freshwater snail, Pomacea
canaliculata (Caenogastropoda, Ampullariidae) from Argentina
C. D. GAMARRA-LUQUES, I. A. VEGA, E. KOCH AND A. CASTRO-VAZQUEZ
Laboratory of Physiology (IHEM-CONICET), Department of Morphology and Physiology, School of Medicine, University
of Cuyo, Casilla de Correo 33, M5500 Mendoza, Argentina.
Key words: Ozmanidae; Ozmana haemophila; Ozmana huarpium, n. sp.; pallial organs; haemocoel
ABSTRACT: A new species of cyclopoid copepod, Ozmana huarpium, is described as a symbiont to Pomacea canaliculata (Lamarck 1822) (Caenogastropoda, Ampullariidae). Rather large numbers (about one hundred copepods per snail) were found, although there was no evidence of harm to the host. To our knowledge, O. haemophila (symbiont to P. maculata), and the currently described species, O. huarpium, are the only copepod species ever recorded as endosymbionts to freshwater invertebrates. While O. haemophila is restricted to the haemocoel of its host, O. huarpium predominate in the penis sheath, the ctenidium and the mantle cavity, figuring in these pallial organs 63-65 % of total mature forms. The sex ratio of the symbiont is skewed to the female side in these organs, specially in male hosts. The hypothesis that a special female tropism for the male host’s pallial organs might ensure interindividual transmission of the symbiont was tested, with indications that the symbiont is mainly transmitted during copulation.
Brief Note
Ultrastructure of the Lyonet’s glands in larvae of Diatraea
saccharalis Fabricius (Lepidoptera: Pyralidae)
ELIANE VICTORIANO AND ELISA A. GREGÓRIO
Centro de Microscopia Eletrônica, Instituto de Biociências, Universidade Estadual Paulista - UNESP, Campus de Botucatu,
18618-000, Botucatu, SP, Brasil.
Keywords: Accessory gland, Insect, Sugarcane borer, Morphology.
ABSTRACT: The Lyonet’s gland is found in Lepidoptera larvae, close to the excretory duct of the silk gland.
The role played by this gland is still uncertain. This work aims to describe the ultrastructure of the Lyonet’s
gland in Diatraea saccharalis larvae, offering suggestions regarding its possible function. The insects were
reared under laboratory-controlled conditions. The glands were conventionally prepared for transmission
(TEM) and scanning (SEM) electron microscopy. SEM showed that Lyonet’s glands are paired small structures
located in the ventral side of the head. They are composed by clustered long cells resembling leaves.
Under TEM observations, each cell is surrounded by a thin basal lamina and contains large stellate nucleus.
The cytoplasm presents large and empty canaliculi with small microvilli. The basal plasma membrane forms
numerous infoldings where numerous and well-developed mitochondria are concentrated. The cytoplasmic
membrane system is poorly developed. Our ultrastructural results suggest that the Lyonet’s gland in D.
saccharalis larvae may be involved in the uptake of small molecules from the hemolymph; no morphological
evidences of macromolecules synthesis and secretion were noticed. The detection of nerve fibers in the gland
suggest a neural control for the glandular cell function.