RESUMEN
In the field of veterinary anatomy, most of the specimens used in practical sessions are perfused with fixatives. Thus, they can be used for a longer time, reducing the number of animals for educational purposes. Formalin is the most commonly used fixative, consisting of a 37% formaldehyde solution. However, formaldehyde is a powerful irritant of the eyes and airways and is considered carcinogenic, causing nasopharyngeal cancer in exposed workers and professionals. In the present study, we explored an alternative method to avoid the use of formaldehyde in specimens used for gross anatomy practical sessions. We propose an inexpensive, non-toxic fixative that is available worldwide, such as sea salt. This method consists of a continuous perfusion of saturated salt solution for a period of 6-8 h, enabling drainage of the solution to avoid a weight increase of the specimen, and allowing salt to be retained in the tissue. The method is based on recirculation of the saturated salt solution instead of maceration. Perfused specimens retained their natural consistency and joint mobility, with no blood, resembling a piece of meat from the slaughterhouse. They could be used immediately without a maceration period, or stored in the fridge until use and then kept in a bath of saturated salt solution for future conservation. In the case of the former, no refrigeration was needed. The specimens did not have an irritating or offensive smell, and could be used for long sessions (several hours per day) and stored for long periods. However, the blood vessels used for perfusion determine the results: a less invasive approach (through common carotid arteries) gave good preservation of the musculoskeletal system, whereas more invasive access to cannulate the abdominal aorta and vena cava caudalis was required to achieve better preservation of the viscera. In conclusion, we propose that perfusion followed by immersion in a saturated salt solution is a good alternative method for the preservation of specimens used in the practical teaching of gross veterinary anatomy. It is a very simple and inexpensive technique, and is much healthier for users than traditional formalin. Moreover, specimens can be preserved for prolonged periods, and maintain a similar appearance and consistency to fresh material.
Asunto(s)
Anatomía Veterinaria/métodos , Embalsamiento/métodos , Fijadores , Cloruro de Sodio , Animales , FormaldehídoRESUMEN
This study was undertaken to get new information on the role played by estrogen (E) on the activity of mink lactotropes. Immunocytochemistry for estrogen receptor (ER) and prolactin (PRL) was applied to assess modifications in the protein production that occur as a result of in vivo changes in the gonadal steroid environment. Variations in the functional activity of lactotropes were demonstrated from the ultrastructural characteristics and morphometric parameters (cellular area, numerical density, and secretory granular size). The present study documents the presence of ER in mink lactotropes revealing the ability of E to regulate the expression of ER in the mink pituitary. Furthermore, all morphological and morphometric parameters of lactotropes activity appeared significantly increased in intact females, killed during the mating period, compared with castrated females under the same photoperiodic conditions. Castration thus blocks the stimulatory effect of photoperiod on metabolic activity of mink lactotropes suggesting that E may participate in the photoperiodic regulation of PRL.
Asunto(s)
Estrógenos/fisiología , Visón/metabolismo , Hipófisis/metabolismo , Prolactina/metabolismo , Receptores de Estrógenos/metabolismo , Animales , Citoplasma/ultraestructura , Gránulos Citoplasmáticos/ultraestructura , Femenino , Inmunohistoquímica , Lactancia/fisiología , Ovariectomía , Hipófisis/química , Hipófisis/ultraestructura , Embarazo , Prolactina/análisis , Receptores de Estrógenos/análisisRESUMEN
The localization and brain stem projections of neurons innervating the carotid sinus of the dog were studied by horseradish peroxidase histochemistry following microinjection of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) under the adventitia of the carotid sinus. Within the brain stem, labeled afferent fibers and presumptive terminals were found bilaterally in the caudal nucleus tractus solitarius (nTS), the area postrema (AP), and the lateral tegmental field (LTF), reaching the area of the nucleus ambiguus (nA). Sparse labeling was also seen in the ipsilateral spinal trigeminal nucleus (SpV) and lateral cuneatus nucleus (LCn). These findings suggest the existence of multiple pathways by which peripheral baroreceptor inputs may influence central cardiovascular-related neurons. In addition to classically defined relay in the nTS, carotid sinus afferents may also interact more directly with these neurons in other brain stem regions.
Asunto(s)
Mapeo Encefálico , Seno Carotídeo/inervación , Bulbo Raquídeo/fisiología , Neuronas Aferentes/fisiología , Vías Aferentes/fisiología , Animales , Perros , Femenino , Peroxidasa de Rábano Silvestre , Masculino , Microinyecciones , Aglutinina del Germen de Trigo-Peroxidasa de Rábano Silvestre Conjugada , Aglutininas del Germen de TrigoRESUMEN
The localization of neurons innervating the carotid sinus of the dog was studied by horseradish peroxidase histochemistry following microinjection of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) under the adventitia of the carotid sinus. Labeled cell bodies were found in the petrosal (198 +/- 108; mean +/- S.D.) and superior cervical ganglia (SCG) (890 +/- 354 mean +/- S.D.) supporting the existence of both a sensory afferent and a sympathetic efferent innervation of the carotid sinus. Labeled neurons in the petrosal ganglion were round pseudounipolar neurons of variable size. Labeled neurons in the SCG were multipolar and appeared distributed over the whole ganglion, but with a higher density toward its caudal half. No labeled perikarya appeared either in the brainstem or in the nodose or jugular ganglia, suggesting that in the dog a vagal pathway for carotid sinus baroreceptor afferents does not exist.
Asunto(s)
Seno Carotídeo/inervación , Neuronas/fisiología , Ganglio Cervical Superior/ultraestructura , Animales , Tronco Encefálico , Seno Carotídeo/fisiología , Perros , Femenino , Peroxidasa de Rábano Silvestre , Masculino , Coloración y Etiquetado , Nervio Vago , Aglutinina del Germen de Trigo-Peroxidasa de Rábano Silvestre Conjugada , Aglutininas del Germen de TrigoRESUMEN
We describe the chronology of the development of the renal system and gonads of 19 greyhound foetuses. The smallest specimens were embedded in paraffin wax and were sectioned serially at 10 microns; the rest were sectioned at 50 microns in an LKB 2250 PMV cryomicrotome. Selected sections were stained with haematoxylin and eosin. The mesonephros, metanephros and gonads were measured in drawings of the sections, using the area fraction programme of a Vids II image analyse.
Asunto(s)
Perros/embriología , Gónadas/embriología , Riñón/embriología , Mesonefro/embriología , Animales , Desarrollo Embrionario y Fetal/fisiología , Femenino , MasculinoRESUMEN
We describe the chronology of development of the stomach and intestine in 18 greyhound foetuses. Using an LKB 2250 PMV cryomicrotome, we obtained corresponding series of sections (50 microns). Very small specimens were embedded in paraffin wax and sectioned at 10 microns. Selected sections were stained with haematoxylin and eosin. For measurement, the fractional area programme of a Vids II image analyser was employed.
Asunto(s)
Perros/embriología , Intestinos/embriología , Estómago/embriología , Animales , Desarrollo Embrionario y Fetal/fisiologíaRESUMEN
In the present study we determined the foetal growth curve of the greyhound. Using an LKB 2250 PMV cryomicrotome, we studied selected sagittal sections from 15 foetuses of the same breed of dog and described the expansion and development of the thoracic and abdominal cavities, the lungs, the liver and (in part) the heart and the thymus. Drawings of the sections were measured by means of a Vids II image analyser and its fractional area programme.