PDF File - The Indian Society for Parasitology

Haemonchus histochemistry, biochemistry and immunology5clinical symptoms, diagnosis, epidemiology, the cuticle (Sood and Kaur, 1977), has been welltreatment and prophylaxis. Subsequently, in a review documented (Sood and Kaur, 1976).on haemonchosis in India, Sood (2003) coveredepidemiology, pathology, diagnosis and control, The histochemical studies on the body wall of H.including resistant strains. Presently, the upcoming contortus (Sood and Kalra, 1977) have revealed thatareas of Haemonchus research, and the ones not fully the cuticle is mainly proteinaceous in nature. Thecovered in the above reviews have been taken up. lipids and PAS-positive materials are only present inHopefully, these three reviews, covering separately cortical layers. In addition, haemoglobin and acidthe various aspects, would provide an up-dated phosphatase (AcPase) are also present. Glycogen,consolidated account of 'Haemonchus to lipids, RNA, AcPase and alkaline phosphatasehaemonchosis' in India.(AkPase) have been reported in the hypodermis. Theoval dense body is composed of keratinous andHISTOCHEMISTRYcollagenous proteins associated with acidmucopolysaccharides. Muscles carry a greaterHistochemical studies have been made on the concentration of glycogen granules andabsorptive surfaces (including in vitro anthelmintic phospholipids. The functional significance of theseeffects) and of the spicules and gubernaculum.components has been fully discussed.Absorptive surfacesThe gut: Singh and Johl (2001) studied the structureParasitic nematodes have two absorptive surfaces- the of the fore-gut (stomodaeum). Histomorphology ofexternal surface or the body wall and the gut, though the intestine has also been studied (Johl, 2003). Soodlatter is the main functional unit from nutrition point of and Sehajpal (1978) made morphological,view. The body wall in nematodes is composed of the histochemical and biochemical studies. The intestinalcuticle, an underlying cell layer (hypodermis or epithelium (IE) is provided with a well-developedepidermis), and the longitudinally orientated somatic brush border (BB) which contains periodic acid-musculature (Wright, 1987). Nematode cuticle is one Schiff- positive mucoproteins. The IE stores glycogenof the most complex acellular structures synthesized and lipids. It stains diffusely for phospholipids andby a living organism. In order to understand the general proteins and also for terminal-NH 2 group. The2+ 3+transport of solutes in the body wall, experimental presence of Fe and Fe containing pigments anddetermination of diffusion coefficients of NaCl and activities of AcPase and AkPase, glucose-6-KCl in adult H. contortus at 298. 16 k has been made phosphatase (G-6-Pase) and 5'-nucleotidase have(Sood et al., 1999).been abserved in IE. Biochemically, pH optimum forintestinal AcPase has been found to be 4.8. BB showsThe nematode gut consists of three parts, a muscular, positive reactions for Acpase and G-6-Pase, andcuticular lined pharynx (oesophagus), a relatively negative for AkPase and 5'-nucleotidase. Presence ofstraight intestine, whose wall is one cell thick and a enzymes in the BB is related to extracellular digestionrectum or cloaca, which like pharynx is lined by and absorption of nutrients.cuticle (Bird, 1971; Chitwood and Chitwood, 1974).Nematodes do not have a continuous muscle sheet Anthelmintic effectsaround the intestine and the pseudocoelomic fluid is inStudy of alterations induced in the absorptive surfacesdirect contact with the basement membrane. The(and neuromuscular system) of the parasites by the innematode intestine is, therefore, an ideal cellvitro incubations with the anthelmintic drugs is ofmonolayer to study the transport mechanisms, theprime importance, particularly in view of theonly diffusion barrier being the basement membranerepeatedly reported resistant strains of H. contortus.(Barrett, 1981).The mechanisms by which the drugs act on theseAbsorptive surfaces in H. contortus have been absorptive surfaces are quite obscure. During theirreviewed (Sood, 1999), under the titles: structure and absorption, anthelmintics are expected to induce somecomposition, immunology and anthelmintic effects. cellular and chemical changes in the absorptivesurfaces. Anthelmintics during their absorptionStructure and compositionaffect/and/or modify the enzyme activity and may alsoalter the normal metabolism of the absorptiveThe body wall: The morphology of the vulvarsurfaces.configurations in the female H. contortus, formed by