Anatomical stages of penile erection in the agouti (Dasyprocta leporina) induced by electro-ejaculation.

The reproductive system of the male agouti is not well documented. This study describes the specific anatomical features of the free part of the penis occurring during penile erection in the agouti. Electro-ejaculation was used to induce erection in three male agoutis that had previously produced offspring. Results proved that there were four stages in the erection process. Stage 1 involved protrusion of the penis from the preputial orifice. The lateral penile cartilages were then spread (stage 2). During stage 3, there was the blooming of the head of the glans penis (penile flower) and eversion of the intromittent sac. The protrusion of the keratinaceous styles and ejaculation occurred during stage 4. This information could assist in semen collection for use in reproductive techniques for the agouti such as artificial insemination.

Liquid and Frozen Storage of Agouti (Dasyprocta leporina) Semen Extended with UHT Milk, Unpasteurized Coconut Water, and Pasteurized Coconut Water.

This study evaluated the effects of semen extension and storage on forward progressive motility % (FPM%) in agouti semen. Three extenders were used; sterilized whole cow's milk (UHT Milk), unpasteurized (CW) and pasteurized coconut water (PCW), and diluted to 50, 100, 150, and 200 × 10(6) spermatozoa/ml. Experiment 1: 200 ejaculates were extended for liquid storage at 5(∘)C and evaluated every day for 5 days to determine FPM% and its rate of deterioration. Experiment 2: 150 ejaculates were extended for storage as frozen pellets in liquid nitrogen at -195(∘)C, thawed at 30(∘) to 70(∘)C for 20 to 50 seconds after 5 days and evaluated for FPM% and its rate of deterioration. Samples treated with UHT milk and storage at concentrations of 100 × 10(6) spermatozoa/ml produced the highest means for FPM% and the slowest rates of deterioration during Experiment 1. During Experiment 2 samples thawed at 30(∘)C for 20 seconds exhibited the highest means for FPM% (12.18 ± 1.33%), 85% rate of deterioration. However, samples were incompletely thawed. This was attributed to the diameter of the frozen pellets which was 1 cm. It was concluded that the liquid storage method was better for short term storage.

Liquid and Frozen Storage of Agouti (Dasyprocta leporina) Semen Extended with UHT Milk, Unpasteurized Coconut Water, and Pasteurized Coconut Water

This study evaluated the effects of semen extension and storage on forward progressive motility % (FPM%) in agouti semen. Three extenders were used; sterilized whole cow's milk (UHT Milk), unpasteurized (CW) and pasteurized coconut water (PCW), and diluted to 50, 100, 150, and 200 ž 10(6) spermatozoa/ml. Experiment 1: 200 ejaculates were extended for liquid storage at 5(∘)C and evaluated every day for 5 days to determine FPM% and its rate of deterioration. Experiment 2: 150 ejaculates were extended for storage as frozen pellets in liquid nitrogen at -195(∘)C, thawed at 30(∘) to 70(∘)C for 20 to 50 seconds after 5 days and evaluated for FPM% and its rate of deterioration. Samples treated with UHT milk and storage at concentrations of 100 ž 10(6) spermatozoa/ml produced the highest means for FPM% and the slowest rates of deterioration during Experiment 1. During Experiment 2 samples thawed at 30(∘)C for 20 seconds exhibited the highest means for FPM% (12.18 ñ 1.33%), 85% rate of deterioration. However, samples were incompletely thawed. This was attributed to the diameter of the frozen pellets which was 1 cm. It was concluded that the liquid storage method was better for short term storage.

The gross and micro anatomy of the accessory sex glands of the male agouti (Dasyprocta leporina).

This study was a follow up to the study on the gross anatomy of the male agouti (Dasyprocta leporina) reproductive system. The seminal vesicles of the agouti are lobulated structures. The mean diameter of the large lumen is 883.6 +/- 76.83 microm. The mucosa (24.1 +/- 0.92 microm), which is lined by pseudo-stratified columnar epithelium is thrown into folds, which often branch. The lamina muscularis mucosa is thin and is made of loose connective tissue containing blood vessels. The mucosa of the leaf-like coagulating glands of the agouti is folded. The mean diameter of the lumen is 488.3 +/- 41.96 microm. The mucosa contains tubuloalveolar glands, which have a mean length of 199.5 +/- 28.83 microm. The thin epithelium, 15.0 +/- 1.25-microm wide, consists mostly of pseudo-stratified columnar cells. The epithelium also has surface modifications in the form of apical blebs and cilia. The epithelium of the agouti's lobulated prostate gland is also folded creating a large lumen with a mean diameter of 995.5 +/- 55.70 microm. The mucosa contains tubular and tubuloalveolar glands, each having a mean length of 134.4 +/- 13.59 microm. The epithelium (13.9 +/- 1.16 microm) consists of pseudo-stratified columnar cells. The pea-shaped bulbourethral gland (BG) of the agouti consists of convoluted tubular, mucous secretory units, which are irregularly shaped each with a mean length of 177.9 +/- 7.10 microm and a mean width of 63.5 +/- 3.97 microm. The BG of the agouti are ventro-lateral to the rectum and dorsally positioned to the pubic symphysis, and connected to the urethra by short ducts.

A preliminary technique for electro-ejaculation of agouti (Dasyprocta leporina).

This study focused on the effectiveness of electro-ejaculation of the agouti (Dasyprocta leporina) and analysis of the collected semen. Sexually mature male agouti were anesthetized with ketamine and electro-ejaculated. The means of ejaculation time was 5.48+/-0.31min, ejaculation voltage was 9.33+/-0.69V, ejaculation voltage range was 6-12V, amps was 0.5-1.5amps, ejaculation volume was 0.47+/-0.12ml and pH was 8.3+/-0.09. Mean spermatozoa concentration, motility and percentage abnormalities were (106.7+/-31.1)x10(6)spermatozoa/ml, 50.44+/-4.44 per cent, and 35.14+/-2.76 per cent, respectively. Thirty percent of the semen samples collected contained spermatozoa. The most significant result from these experiments was the inverse relationship between ejaculation time and ejaculate volume, which suggests that the maximum ejaculation time for electro-ejaculation of the agouti should not proceed beyond 6min. Secondly, the results indicate that the time of the off periods should be shortened to 3-4s.

Spermatozoal morphologies and fructose and citric acid concentrations in agouti (Dasyprocta leporina) semen.

This study was conducted to identify the levels of fructose and citric acid, and sperm morphologies in agouti (Dasyprocta leporina) semen. These parameters may be important in identifying highly fertile semen from the agouti. The objectives were: (1) to investigate spermatozoal abnormalities in agouti semen and (2) to determine the concentrations of seminal fructose and citric acid in agouti semen samples. Semen samples were collected from 16 anaesthetised male agouti by electro-ejaculation. Fructose and citric acid concentrations were 256.86+/-63.54 mg/dl and 1877+/-147 mg/dl, respectively, measured with ELISA kits. Sperm morphologies, examined using eosin-negrosin staining, showed 11 morphologies. The most abundant (68.5 per cent) sperm morphology (M1) showed no known sperm defects. Means for head, mid piece, tail and total length of the agouti spermatozoa was 5.23+/-0.04 microm, 5.18+/-0.08 microm, 37.52+/-0.24 microm and 47.96+/-0.25 microm, respectively for M1 sperm. The means of spermatozoa head and mid piece width and semen volume were 3.26+/-0.04 microm, 0.70+/-0.02 microm and 0.47+/-0.16 ml, respectively. It was concluded that as the fructose concentration in agouti ejaculate increased the percentage of spermatozoa with known spermatozoa defects increased (r=0.506; P<0.037; n=32). It is suggested that the M1 sperm could be the most competitive spermatozoa in agouti ejaculate. In conclusion standards for identifying fertile agouti semen were established.

A preliminary technique for electro-ejaculation of agouti (Dasyprocta leporina).

This study focused on the effectiveness of electro-ejaculation of the agouti (Dasyprocta leporina) and analysis of the collected semen. Sexually mature male agouti were anesthetized with ketamine and electro-ejaculated. The means of ejaculation time was 5.48+/-0.31min, ejaculation voltage was 9.33+/-0.69V, ejaculation voltage range was 6-12V, amps was 0.5-1.5amps, ejaculation volume was 0.47+/-0.12ml and pH was 8.3+/-0.09. Mean spermatozoa concentration, motility and percentage abnormalities were (106.7+/-31.1)x10(6)spermatozoa/ml, 50.44+/-4.44%, and 35.14+/-2.76%, respectively. Thirty percent of the semen samples collected contained spermatozoa. The most significant result from these experiments was the inverse relationship between ejaculation time and ejaculate volume, which suggests that the maximum ejaculation time for electro-ejaculation of the agouti should not proceed beyond 6min. Secondly, the results indicate that the time of the off periods should be shortened to 3-4s.

Spermatozoal morphologies and fructose and citric acid concentrations in agouti (Dasyprocta leporina) semen.

This study was conducted to identify the levels of fructose and citric acid, and sperm morphologies in agouti (Dasyprocta leporina) semen. These parameters may be important in identifying highly fertile semen from the agouti. The objectives were: (1) to investigate spermatozoal abnormalities in agouti semen and (2) to determine the concentrations of seminal fructose and citric acid in agouti semen samples. Semen samples were collected from 16 anaesthetised male agouti by electro-ejaculation. Fructose and citric acid concentrations were 256.86+/-63.54 mg/dl and 1877+/-147 mg/dl, respectively, measured with ELISA kits. Sperm morphologies, examined using eosin-negrosin staining, showed 11 morphologies. The most abundant (68.5%) sperm morphology (M1) showed no known sperm defects. Means for head, mid piece, tail and total length of the agouti spermatozoa was 5.23+/-0.04 microm, 5.18+/-0.08 microm, 37.52+/-0.24 microm and 47.96+/-0.25 microm, respectively for M1 sperm. The means of spermatozoa head and mid piece width and semen volume were 3.26+/-0.04 microm, 0.70+/-0.02 microm and 0.47+/-0.16 ml, respectively. It was concluded that as the fructose concentration in agouti ejaculate increased the percentage of spermatozoa with known spermatozoa defects increased (r=0.506; P<0.037; n=32). It is suggested that the M1 sperm could be the most competitive spermatozoa in agouti ejaculate. In conclusion standards for identifying fertile agouti semen were established.

Bovine epigastric heteropagus in Trinidad and Tobago: a case study

Congenital duplications are common causes of dystocia in farm animals, especially in cattle. Heteropagus or conjoined asymmetric twins can be differentiated into a dominant and a parasitic twin, which can be classified further by the development of the parasitic twin and its anatomical attachment to the dominant twin (autosite). In epigastric heteropagus, the parasitic twin is attached to the autosite in the epigastric area. Epigastric heteropagus is a very rare condition in all species, but it has previously been reported in human beings (Chadhaand others 1993). There have been no reports of heteropagus in cattle in Trinidad and Tobago, and there is a paucity of information on bovine epigastric heteropagus in the literature. Reports of congenital abnormalities in Trinidad include craniopagus in a calf (Isitor and Adogwa 1992), perosomus elumbus in a goat (Cazabon and others 1994) and cephalothoracopagus in sheep (Cazabon and Adogwa 2003). The interest in congenital abnormalities lies mainly in the aetiology and its implications, such as genetic defects and environmental toxins. This short communication describes the firstcase of epigastric heteropagus in cattle reported in Trinidad and Tobago.

Origins of colonic preganglionic parasympathetic motoneurons from the central nervous system: A wheatgem agglutinin-horseradish peroxidase study in the ferret (Mustela Putorius furo)

The wheat gem Agglutinin-Horseradish Peroxidase (WGA-HRP)trabsneuronal nerve tracing technique was used to study the localization of colonic preganglionic parasympathetic neurons in the central nervous system of the fettet. The entire colon, from the iliocecal junction to the colorectal junction was subdivided into four segments and the muscular wall of each segment injected separately with the tracer. The ferrets used as controls were also subdivided into four groups. The first group was injected with normal saline, the second group with the tracer following bilateral trunkal vagotomy, the third group intraperitoneally and the fourth group had tracer injection into the hepatic portal vein. The experimental as well as the control of ferrets were allowed to survive for 24 to 96 hours after which they were anaesthetized and perfused sequentilly with normal saline, buffered fixative, and buffered sucrose.Serial transverse frozen sections were taken from the brainstem and the sacral segments of the spinal cord of the ferrets. These were then processed for WGA-Hrp neurohitochemistry and analyzed under light and dark field illuninations. The results of the study show that the dorsal motor nucleus of the vagus nerve (DMX) supplies the anterior 3 segments of the colon while the sacral segment of the spinal cord supplies the post 2 segments of the colon. It is concluded that in the innervation of the colon there is an overlap between the areas supplied by the DMX and those supplied by the sacral segment of the spinal cord (AU)

Origins of colonic preganglionic parasympathetic motoneurons from the central nervous system: a wheatgerm agglutinin-horseradish peroxidase study in the ferret (Mustela Putorius Furo).

The Wheat germ Agglutinin-Horseradish Peroxidase (WGA-HRP) transneuronal nerve tracing technique was used to study the localization of colonic preganglionic parasympathetic neurons in the central nervous system of the ferret. The entire colon, from the iliocecal junction to the colorectal junction was subdivided into four segments and the muscular wall of each segment injected separately with the tracer. The ferrets used as controls were also subdivided into four groups. The first group was injected with normal saline, the second group with the tracer following bilateral trunkal vagotomy, the third group intraperitoneally and the fourth group had tracer injection into the hepatic portal vein. The experimental as well as the control ferrets were allowed to survive for 24 to 96 hours after which they were anaesthetized and perfused sequentially with normal saline, buffered fixative and buffered sucrose. Serial transverse frozen sections were taken from the brainstem and the sacral segments of the spinal cord of the ferrets. These were then processed for WGA-HRP neurohistochemistry and analyzed under light and dark-field illuminations. The results of the study show that the dorsal motor nucleus of the vagus nerve (DMX) supplies the anterior 3 segments of the colon while the sacral segment of the spinal cord supplies the post 2 segments of the colon.

Origins of colonic preganglionic parasympathetic motorneurons from the central nervous system: a wheat germ agglutinin- horse radish peroxidase study in the ferret (Mustela putorius furo)

The Wheat germ Agglutinin Horseradish Peroxidase (WGA-HRP) transneural nerve tracing technique was used to study the localisation of colonic preganglionic parasympathetic neurons in the central nervous system of the ferret. THe entire colon, from the iliocecal junction to the colorectal junction was subdivided into four segments and the muscular wall of each segment injected separately with the tracer. The ferrets used as controls were also subdivided into four groups. The first group was injected with normal saline, the second group was the tracer following bilateral trunkal vagotomy, the third group intraperitoneally and the fourth group had tracer injected into the hepatic portal vein. The experimental as well as control ferrets were allowed to survive for 24 to 96 hours after which they were anaesthetized and perfused sequentially with normal saline, buffered fixative and buffered sucrose. Serial transverse frozen sections were taken from the brainstem and the sacral segments were taken from the spinal cord of the ferrets. These were then processed for WGA-HRP neurohistochemistry and analysed under light and dark illuminations. THe results of the study show that the dorsal motor nucleus of the vagua nerve (DMX) supplies the anterior 3 segments of the colon while the sacral segment of the spinal cord supplies the post 2 segments of the colon.

Origins of colonic preganglionic parasympathetic motorneurons from the central nervous system: a wheat germ agglutinin- horse radish peroxidase study in the ferret (Mustela putorius furo)

The Wheat germ Agglutinin Horseradish Peroxidase (WGA-HRP) transneural nerve tracing technique was used to study the localisation of colonic preganglionic parasympathetic neurons in the central nervous system of the ferret. The entire colon, from the iliocecal junction to the colorectal junction was subdivided into four segments and the muscular wall of each segment injected separately with the tracer. The ferrets used as controls were also subdivided into four groups. The first group was injected with normal saline, the second group was the tracer following bilateral trunkal vagotomy, the third group intraperitoneally and the fourth group had tracer injected into the hepatic portal vein. The experimental as well as control ferrets were allowed to survive for 24 to 96 hours after which they were anaesthetized and perfused sequentially with normal saline, buffered fixative and buffered sucrose. Serial transverse frozen sections were taken from the brainstem and the sacral segments were taken from the spinal cord of the ferrets. These were then processed for WGA-HRP neurohistochemistry and analysed under light and dark illuminations. The results of the study show that the dorsal motor nucleus of the vagua nerve (DMX) supplies the anterior 3 segments of the colon while the sacral segment of the spinal cord supplies the post 2 segments of the colon.

Preganglionic parasympathetic vagal innervation of the pylorus: a HRP study in the ferret (Mustela Putorius Furo)

The brainstem origins of vagal preganglionic parasympathetic neurons innervating the pylorus was studied in the ferret using the Horseradish peroxidase (HRP) neurohistochemical technique. A total of 12 adult male and female ferrets (8 experimental and 4 controls) were used for the study (AU)

Demostration of collaterization of the abdominal vagus in the rat using the double flourescent dyes technique [abstract]

Since the earlier report of Mitchel (1935), the central origin of preganglionic parasympathetic fibres has been studied by various investigators using different techniques and animal species. While it is now generally accepted that the dorsal motor nucleus of the vagus nerve (DMNV) is the principal source of preganglionic parasympathetic fibres to several organs in the thorax and abdomen, there has been persistent controversy as regards topographic representation of these organs in the DMNV. In a previous study in the ferret using the Horseradish peroxidase technique, some degree of topographic representation of the subdiaphragmatic part of the gastrointestinal tract was observed. It was, however, noted that no part of this nucleus is exclusively responsible for innervation of any segment of the gut. The author went on to speculate that the pattern of representation of the gut demostrated in the study might supply more than one segment of the gut by collaterization. The present study was thus designed to test this hypothesis. A total of 16 male and female Sprague Dawley rats weight range from 350 to 500g were used for the study. Four of these rats were used as control while the remaining 12 were used as experimental rats. Eight rats were injected with 1æ1 of 5 percent Diamidino yellow (DY) by multiple penetrations into the walls of the stomach while the same quantity and percentage of Fast blue (FB) was injected in the same manner into the walls of the duodenum and upper jejunum in the eight rats. Two rats had multiple injections of 1æ1 of 5 percent DY into the walls of the stomach only and two other rats had multiple injections of 1æ1 of 5 percent FB into the walls of the duodenum and upper jejunum only. Four control rats were injected with 1æ1 of normal saline (2 in the stomach and 2 in the intestine) in the same manner in which the experimental rats were injected. Each rat was anaesthetized with pentobarbitone and then perfused transcardially 14 days after the injections. Serial sections of the medulla were cut at 20-micron thickness with the cryosat and the sections examined with a Nikon Apaphot flourescence microscope. The result of the experiment revealed that in 8 rats injected with DY and FB some cells of the DMNV were labelled with DY only, some with FB only and some were doubly labelled with FB and DY. The two rats injected with FB showed FB labelled cells only while the two injected with DY showed DY labelled cells only. (AU)

Increased BAEP latency and reduced brain cytochrome c oxidase activity observed in the Suzuki model of Alzheimer's disease [abstract]

Cytochrome c oxidase (COX), the terminal respiratory enzyme, is reported to be deficient and to exhibit reduced activity in a number of neurodegenerative disorders. The Alzheimer's rabbit model is based on the intracerebral injection of Holt's adjuvant, an aluminum salt solution. This model was used to compare the brain activity and the activity of brain COX in treated and controlled rabbits. Of a total of 26 New Zealand white rabbits, thirteen were injected intracerebrally with Holt's adjuvant solution, five with physiologically saline solution and the remainder were kept as controls. The auditory responses (BAEP) of the rabbits were monitored for 14 days before injections and 14 days thereafter. The animals were then sacrificed and brain mitochondrial extracts were used for SDS-PAGE analysis, difference spectra spectrophotometry and polarographic assays. The results of SDS-PAGE showed that there were no differences in the protein composition of the brain mitochondria of the three groups. Similarly, difference spectra (reduced minus oxidized, 400-630 nm) from both treated groups were identical to that of the control with characteristic maxima centered around 434, 550 and 604 nm. Polarographic assays, however, showed that while the enzyme from both treated groups displayed the characteristic biphasic kinetics, there was reduced activity in the enzymes from the brain of rabbits receiving the adjuvant but not the saline solution. This result is significant in light of the fact that several researchers have reported reduced activity of COX from Alzheimer's disease (AD) patients. Of particular significance, BAEP results reveal an increase in the interpeak latency between peaks III and V of the Holt's injected but not the saline injected or control rabbits. This latter result suggests that monitoring the BAEP might provide a simple non-invasive method for confirming AD. (AU)

Effect of water extract of carica papaya seed on the germinal epithelium of the seminiferous tubules of Sprague Dawley rats.

Extracts from different parts of the papaya have been reported to decrease the testicular weight of Wistar rats when administered orally for 8 weeks. It was however reported that suppression of spermatogenesis was observed in these rats following the administration of papaya seed extract. No histological abnormality was observed in these animals. In this experiment, water extract of papaya seeds, was administered orally to Sprague Dawley rats ad libitum for 8 weeks. Results showed that 3 weeks after commencement of this administration, the lumina of the seminiferous tubules were more prominent and empty in the experimental animals with no evidence of spermatids and spermatozoa. It also showed that the lateral walls of adjacent Sertolil cells lost contact with each other.

The oculomotor and trochlear nuclei in the one humped camel (Camelus dromedarius).

Literature on the organization of the oculomotor and trochlear nuclei of large animals is scanty. There were no reports on the organization of the oculomotor and trochlear nuclei of the camel, hence this study. Nine brains were used for the study. The brainstems were double-embedded in celloidin and paraffin and were cut serially at 24 microns and stained with toluidine blue. Light microscopic studies of the nuclei showed that the principal oculomotor nuclei were not subdivided and were composed of large multipolar nerve cell bodies that had a mean length of 30 +/- 5 microns. The nucleus was 2.4 mm long, 0.7 mm wide and 1.1 mm high. The Edinger-Westphal nucleus was small and was made up of elongated oval cell bodies that had a mean length of 33 +/- 5 microns and a mean diameter of 10 +/- 2 microns. The trochlear nucleus was located caudal to the oculomotor nucleus from which it was separated by a gap. The nerve cell bodies of the trochlear nuclei were similar to those of the oculomotor nuclei. The cell bodies had a mean length of 20 +/- 2.5 microns and a mean width of 18 +/- 3 microns. The caudal central nucleus was indistinct. It was concluded, that the oculomotor and trochlear nuclei of the camel are similar in their general organization to those of other animals but differences exist in the development and organization of the component parts.