Histochemical and morphometric study of the cricoarytenoideus lateralis muscle in the horse.

Histochemical and morphometric parameters of the cricoarytenoideus lateralis muscle of the horse are presented. Using myosin ATPase staining after acid preincubation, 3 fibre types (I, IIA and IIC) were identified. Using NADH-TR staining, type I fibres showed high oxidative capacity, whereas type II fibres had high or low oxidative capacity. The type I to type II ratio was of 35:65. This ratio remained constant in the age range examined. Statistically significant (p < 0.01) differences were found in values for fibre size between groups of horses weighing more than 500 kg and less than 400 kg. Mean area of type II fibres was greater (p < 0.001) than that of type I fibres. There were no significant differences in mean area between left and right muscles in the group of animals with less weight. In contrast, significant differences (p < 0.05) in mean area between left and right muscles were found for type I fibres in the group of animals exhibiting a higher weight. The histographical distribution of fibre type areas was unimodal. Most adult horses showed muscle fibre type grouping in the left muscle.

Morphometric study of the recurrent laryngeal nerve in young 'normal' horses.

Quantitative measurements were made on cross-sectional preparations of the distal part of the recurrent laryngeal nerve (RLN) from nine young mixed-breed horses to establish reference values for the total number of myelinated fibres, mean fibre diameter and percentage of thickest fibres (over 9.5 microns) and to delineate diameter distribution curves. The total number of myelinated fibres, mean fibre diameter and percentage of thickest fibres for the left RLN were significantly lower than those of the right RLN (P < 0.005). The distribution of fibres was unimodal. The fibre diameter ranged from 1 micron to 17 microns. Approximately, 95 per cent of fibres had a diameter larger than 5 microns.

Muscular pathology in equine laryngeal neuropathy.

Three adductor muscles of the larynx, the cricoarytenoideus lateralis (CAL), the arytenoideus transversus (AT) and the ventricularis (Ve), from 36 horses were examined histologically. The neurogenic changes seen in each muscle were evaluated qualitatively. In addition, in 6 horses with clinical and subclinical signs of neurogenic atrophy, measurements of muscle fibre area were performed. Neurogenic changes observed in the Ve were less than in CAL and AT. Measurements of muscle fibre area also demonstrated that CAL and AT showed a wider range of pathological changes than did Ve. The results show that denervation does not uniformly affect all adductor muscles of the larynx. On the other hand, the appearance in some animals of fibre type grouping in the right AT to the same or to a greater extent than in the left AT supports the classification of equine laryngeal neuropathy as a distal axonopathy.

[Lymphaticovenous communication in the mammary gland of the female dog]. / Communications lymphatico-veineuses dans la glande mammaire de la chienne.

Lymphaticovenous Communications were searched in the mammary glands of 24 bitches. Injections of indian ink into the interstice of living animals were followed after death by the filling of the veins with latex and barium sulphate. Afterwards, the used techniques were: microdissection, angiography, clarification and histological section. The results obtained would seem to prove the existence of Lymphovenous Anastomoses. The roles of these communications in the canine mammary gland neoplasia are discussed.

[Topography of the lymphatic collecting ducts of the mammary glands of the dog]. / Topographie des collecteurs lymphatiques mammaires de la chienne.

The topography of the lymph drainage was examined by in vivo injections of india ink into the mammary parenchyma of 73 female dogs. Only one gland was injected at a time on each side. Only the cranial abdominal mammary gland had direct drainage to the axillary as well as to the superficial inguinal nodes. The principal routes of drainage differ for each gland. The glands on each side are completely independent as regards their lymph drainage. The cranial thoracic mammary glands on each side had their own collecting duct which led to the sternal lymph nodes. The results of this study suggest to develop a new model for the surgical extirpation of mammary tumors in the bitch.

The urethral muscle (musculus urethralis) of the female calf. Anatomical, histological, histochemical and morphometrical data.

Parts of the female urethra were examined topographically and microscopically in the female calf. The thickness and the straight course of the fibres of the musculus urethralis could best be analyzed in the ventromedian region of the urethra. Examination of the surface area and the distribution of the two primary metabolic fibre types showed that the urethral muscle is capable of contracting quickly with predominantly anaerobic metabolism. The different relationships between type I and type II fibres could be determined also in relation to the position of the lamina propria mucosae.

[Effects of 2 anabolizing substances with estrogenic action on the urethral muscle of the calf. Histochemical and morphometric study]. / Effets de deux substances anabolisantes à action oestrogénique sur le muscle urétral du veau. Etude histochimique et morphométrique.

The testing of anabolizer utilization in cattle farming needs quick, sure and cheap detection techniques. The administration of oestrogen to cattle produces hypertrophy of the prostate, bulbourethral glands and urethral muscle. The aim of this study was to quantify the effect of the association of zeranol (an hormonomimetic drug acting as an oestrogen) and trembolone (a steroidic structure originating from testosterone) on the urethral muscle of bull calves which is easy to sample in the slaughter-house. An histoenzymological and morphometric study of the urethral muscle of 90 bull calves that had been treated showed considerable hypertrophy in transversal sections of the muscle fibers that was increased by more than 90% in the two main types of striated muscle fiber. The morphological method used is proposed for monitoring the meat of untreated bull calves, requested by a class of consumers.