RESUMEN
INTRODUCTION: A recent study has shown a close neuroanatomical relationship between the enkephalinergic (methionine-enkephalin) and tachykininergic (substance P) systems in the alpaca diencephalon. In this study, our aim is to show this relationship in the alpaca brainstem. MATERIAL AND METHODS: Using an immunohistochemical technique, the distribution of immunoreactive (Ir) fibers and cell bodies containing substance P (SP) or methionine-enkephalin (MET) has been studied in the alpaca brainstem. Five adult males were used; brain tissue was fixed and processed by standard methods. RESULTS: SP- and MET-Ir fibers showed a widespread and similar distribution in the mesencephalon, pons and medulla oblongata. The co-localization of fibers containing SP or MET was found in most of the nuclei/tracts of the alpaca brainstem. This close neuroanatomical relationship suggests multiple physiological interactions between both neuropeptides. The distribution of the cell bodies containing SP was very restricted (cell bodies were only observed in a few nuclei located in the mesencephalon and medulla oblongata), whereas MET-Ir perikarya showed a moderately widespread distribution in the mesencephalon, pons and medulla oblongata. CONCLUSIONS: This study increases the knowledge on the neuroanatomical distribution/relationship of the tachykininergic (SP) and enkephalinergic (MET) systems in the alpaca central nervous system.
Asunto(s)
Camélidos del Nuevo Mundo , Animales , Tronco Encefálico/metabolismo , Camélidos del Nuevo Mundo/metabolismo , Diencéfalo/metabolismo , Encefalina Metionina/metabolismo , Masculino , Sustancia PRESUMEN
INTRODUCTION: In the alpaca diencephalon, the distribution of immunoreactive cell bodies and fibers containing methionine-enkephalin (MET) or substance P (SP) has been studied. MATERIAL AND METHODS: The immunohistochemical study was performed by standard method on the diencephalon of four male alpacas that lived at sea level. RESULTS: Nerve fibers containing MET or SP were widely distributed in the thalamus and hypothalamus. METand SP-immunoreactive fibers showed a similar distribution in the whole diencephalon. Immunoreactive cell bodies containing MET or SP were only observed in the hypothalamus. The distribution of MET-immunoreactive cell bodies was more widespread than that observed for cell bodies containing SP. CONCLUSIONS: A close neuroanatomical relationship between the tachykininergic (SP) and enkephalinergic (MET) systems was observed in the whole diencephalon suggestive of the existence of multiple physiological interactions between both systems.
Asunto(s)
Encefalina Metionina/metabolismo , Hipotálamo/anatomía & histología , Hipotálamo/metabolismo , Sustancia P/metabolismo , Tálamo/anatomía & histología , Tálamo/metabolismo , Animales , Camélidos del Nuevo Mundo , MasculinoRESUMEN
Using an immunocytochemical technique, we have studied in the alpaca brainstem the distribution of immunoreactive structures containing prodynorphin (alpha-neoendorphin)- and pro-opiomelanocortin (adrenocorticotrophin hormone (18-39) (ACTH), beta-endorphin (1-27))-derived peptides. No peptidergic-immunoreactive cell body was observed. Immunoreactive fibres were widely distributed, although in most of the brainstem nuclei the density of the peptidergic fibres was low or very low. In general, the distribution of the immunoreactive fibres containing the peptides studied was very similar. A close anatomical relationship occurred among the fibres containing alpha-neoendorphin, ACTH or beta-endorphin (1-27), suggesting a functional interaction among the three peptides in many of the brainstem nuclei. The number of fibres belonging to the prodynorphin system was higher than that of the pro-opiomelanocortin system. A moderate/low density of immunoreactive fibres was observed in 65.11% (for alpha-neoendorphin (1-27)), 18.18% (for ACTH) and 13.95% (for beta-endorphin) of the brainstem nuclei/tracts. In the alpaca brainstem, a high density of immunoreactive fibres was not observed. The neuroanatomical distribution of the immunoreactive fibres suggests that the peptides studied are involved in auditory, motor, gastric, feeding, vigilance, stress, respiratory and cardiovascular mechanisms, taste response, sleep-waking cycle and the control of pain transmission.
Asunto(s)
Hormona Adrenocorticotrópica/metabolismo , Tronco Encefálico/metabolismo , Endorfinas/metabolismo , Fragmentos de Péptidos/metabolismo , Proopiomelanocortina/metabolismo , Precursores de Proteínas/metabolismo , betaendorfina/metabolismo , Animales , Camélidos del Nuevo Mundo , Inmunohistoquímica , Masculino , Neuronas/metabolismo , Coloración y EtiquetadoRESUMEN
Camelids (llamas, alpacas, vicuñas, guanacos) are important for the economy of South America and Eimeria infections are important as cause of mortality in camelids. Of the five most prevalent species of Eimeria in South American camelids, Eimeria macusaniensis, Eimeria lamae, Eimeria alpacae, Eimeria punoensis, and Eimeria ivitaensis, E. macusaniensis is considered the most pathogenic. There is considerable confusion concerning the endogenous developmental stages of Eimeria spp. in camelids. Many papers on camelid coccidiosis were published in local Peruvian journals, not easily accessible to wider audience. The objective of the present paper is to summarize information on history, validity of Eimeria species, life cycle, pathogenicity, prevalence, epidemiology, diagnosis, and control of coccidiosis in camelids.
Asunto(s)
Camélidos del Nuevo Mundo/parasitología , Coccidiosis , Eimeria/patogenicidad , Animales , Coccidiosis/diagnóstico , Coccidiosis/epidemiología , Coccidiosis/terapia , Coccidiosis/veterinaria , Heces/parasitología , Prevalencia , América del Sur/epidemiologíaRESUMEN
INTRODUCTION: The distribution of the immunoreactive cell bodies and fibers containing neurotensin in the alpaca diencephalon was determined by an immunohistochemical technique. MATERIAL AND METHODS: The study was carried out in four male alpacas that lived at sea level. Brains of deeply anesthetized animals were fixed by perfusion with 4% paraformaldehyde. Cryostat sections were stained by a standard immunohistochemical method. RESULTS: Cell bodies containing neurotensin were observed in the zona incerta and hypothalamus. A low/moderate density of these cell bodies was observed in the lateral hypothalamic area, anterior and dorsal hypothalamic areas, suprachiasmatic nucleus, periventricular region of the hypothalamus and in the ventromedial hypothalamic nucleus. In both thalamus and hypothalamus, immunoreactive fibers showed a widespread distribution. In the thalamus, a high density of these fibers was mainly found in the midline nuclei, whereas in the hypothalamus a high density was in general observed in the whole structure. CONCLUSIONS: In comparison with other mammals, the thalamus of the alpaca showed the most widespread distribution of neurotensin-immunoreactive fibers. The widespread distribution of neurotensin through the alpaca diencephalon suggests that the peptide can be involved in many physiological actions.
Asunto(s)
Camélidos del Nuevo Mundo , Diencéfalo/metabolismo , Neurotensina/metabolismo , Animales , Cuerpo Celular/química , Cuerpo Celular/metabolismo , Diencéfalo/química , Hipotálamo/química , Hipotálamo/metabolismo , Inmunohistoquímica , Masculino , Neurotensina/químicaRESUMEN
Mycobacterium avium subsp. paratuberculosis (MAP) is the etiologic agent of paratuberculosis. The organism causes disease in both domestically managed and wild ruminant species. South American camelids have a long, shared history with indigenous people in the Andes. Over the last few decades, increasing numbers of alpacas were exported to numerous countries outside South America. No paratuberculosis surveillance has been reported for these source herds. In this study, individual fecal samples from 85 adult alpacas were collected from six separate herds in the Chilean Altiplano. A ParaTB mycobacterial growth indicator tube (MGIT) liquid culture of each individual fecal sample, followed by real-time polymerase chain reaction (PCR) protocol was used for confirmation. DNA extracts from a subset of confirmed MAP isolates were subjected to mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing. Fifteen alpaca were fecal culture test-positive. Five false-positive culture samples were negative on PCR analysis for Mycobacterium avium subsp. avium (MAA), Mycobacterium bovis (M. bovis), and the 16 S rDNA gene. Three MAP isolates subset-tested belonged to the same MIRU-VNTR type, showing four repeats for TR292 (locus 1) in contrast to the three repeats typical of the MAP reference strain K10. The number of repeats found in the remaining loci was identical to that of the K10 strain. It is not known how nor when MAP was introduced into the alpaca population in the Chilean Altiplano. The most plausible hypothesis to explain the presence of MAP in these indigenous populations is transmission by contact with infected domestic small ruminant species that may on occasion share pastures or range with alpacas. Isolation of this mycobacterial pathogen from such a remote region suggests that MAP has found its way beyond the confines of intensively managed domestic agriculture premises.