Veterinary Research Forum

Abstract Chemotherapy agents impose harmful side effects beside their therapeutic properties. This study aimed to uncover the ameliorative effects of thiamine (VitB1) on sperm characteristics and in vitro fertilizing ability in methotrexate (MTX) exposed mice. For this purpose, 36 apparently healthy adult male mice were randomly divided into six groups (n = 6), including control (0.10 mL normal saline per day; intraperitoneally [IP]), sham (10.00 mg kg^-1 per week MTX; IP), positive control group (100 mg kg^-1 per day VitB1; IP), and three experimental groups (25.00, 50.00, and 100 mg kg^-1 per day; IP VitB1 plus MTX, respectively; IP). Then, sperm parameters and the in vitro fertilizing potentials were assessed. The sperm count, motility, and viability in the sham group showed a significant decrease in comparison with the VitB1-treated and control groups. In the VitB1 100 mg kg^-1 + MTX group, there was a significant increase in sperm count in comparison with the sham group. The sperms with DNA damages and immature sperms in the sham group significantly increased in comparison with the positive control and control groups. In vitro fertilization and embryonic development in the sham group were decreased in comparison with both the control and VitB1 groups. In VitB1 50.00 mg kg^-1 and 100 mg kg^-1 + MTX groups, there was an increase in the fertilization rate, along with embryonic development promotion. According to the results of this study, thiamine ameliorates toxic effects of MTX on sperm traits and in vitro fertilizing potentials by constraining oxidative stress.

Abstract Cisplatin (CS) is a broad-spectrum chemotherapeutic agent that causes serious adverse effects, such as cardiotoxicity, despite its potent anti-tumor efficacy. This study aimed to evaluate the cardioprotective effects of betaine in rats exposed to repeated low-dose CS administration using histopathological and immunohistochemical methods. Forty female Wistar albino rats were divided into four groups, including control, betaine, CS, and CS + betaine. Betaine (250 mg kg^-1) was administered orally on a daily basis for four weeks, while CS (8.00 mg kg^-1) was administered intraperitoneally once a week for the same duration. Cardiomyocytes were then examined using histopathological and immunohistochemical methods. The data were analyzed using one-way analysis of variance and Tukey tests. Histopathological analysis revealed cardiomyocyte disorganization, myofibril loss, and increased eosinophilia in the CS group. Betaine treatment partially prevented CS-induced histological damage, contributing to the cardiac muscle structure preservation. Immunohistochemical analyses demonstrated a significant increase in transforming growth factor-beta and interferon gamma expressions in the CS group, whereas betaine administration reduced transforming growth factor-beta levels. Interleukin 6 expression was lower in the CS + betaine group compared to the CS group. No significant differences were observed between groups regarding Interleukin -1β expression. These findings suggest that betaine may have protective effects against CS-induced cardiotoxicity. Its anti-inflammatory properties appear to mitigate cardiomyocyte damage.

Abstract This study investigated carbendazim (CBZ)-induced hepatic dysfunction and the mechanistic pathway regarding the protective effect of melatonin (MEL). Twenty-eight male rats were grouped as follows: Control, CBZ (150 mg kg^-1), MEL (20.00 mg kg^-1), and CBZ + MEL. The experiment was conducted for 60 days. Tissue samples were stained with Hematoxylin and Eosin and immuno-fluorescence methods to examine apoptotic pathway. Also, hepatic enzymes and miR-122 expression were evaluated. The findings indicated that the CBZ group exhibited an increase in degenerated hepatocytes, hyperemia of sinusoids, and leukocyte infiltration, accompanied by elevated levels of aspartate aminotransferase and alanine aminotransferase, as well as up-regulation of miR-122. Also, there was a significant increase in the fluorescence intensities of caspase-3 and Bax in the CBZ group, whereas a substantial reduction in the fluorescence intensity of Bcl-2 was recorded. In contrast, the simultaneous administration of MEL alongside CBZ was shown to be effective in improving histological structure, decreasing levels of aspartate aminotransferase and alanine aminotransferase, reducing the apoptosis index, and modulating the expression of miR-122 in comparison with the CBZ-only group. The increased expression of miR-122 noted in the CBZ group may correlate with an elevation in the immunoreactivity of apoptosis markers and alterations in liver architecture. Additionally, MEL seems to alleviate CBZ-induced hepatotoxicity by down-regulating miR-122 expression, diminishing the fluorescence intensity of caspase-3 and Bax, and enhancing the immunoreactivity of Bcl-2. Collectively, the regulation of miR-122 may serve as a potential mechanism by which MEL confers its protective effects against liver damage induced by CBZ.

Abstract To improve the structure of the heart muscle after myocardial infarction, methods of regenerative medicine are used. One of the promising areas is the intra-myocardial administration of acellular allogeneic biomaterial (AB). The AB stimulates the regeneration of organs and tissues. But, the effect of AB on the myocardium after its fibrous ischemic degeneration has not been assessed. The aim of the study was to assess the morphological structure of the heart after cryodestruction in the late period and the use of AB. Chronic myocardial infarction was modeled in 80 male rats. To simulate chronic myocardial infarction and fibrosis formation, contact cryodestruction was performed. After 45 days, during repeated thoracotomy in the main group, AB suspension was injected into the area of the cryogenic myocardial scar. Six injections of 0.50 mg of dry substance were administered. In the control group, physiological solution was injected. After AB administration, following 7, 14, 30, and 45 days, the animals were withdrawn from the experiment, and the hearts were excised for histological and immunohistochemical studies. The AB underwent gradual phagocytosis by macrophages and gradually replaced by loose fibrous connective tissue with the presence of cardiac troponin I⁺ labeled muscle cells, which over time underwent hypertrophy. Cardiomyocytes were grouped in the AB implantation zone as separate clusters. The heart mass did not change in both experimental groups. The use of AB in the area of the formed cryogenic myocardial scar promoted the transformation of dense fibrous connective tissue into loose tissue and its replacement with cardiac muscle tissue.

Abstract Alectoris chukar (AC) is a common model organism in biological research. To understand oogenesis and folliculogenesis mechanisms in bird reproduction, we analyzed the ovarian tissue structure of AC at embryonic and pre-pubertal stages. Fertilized eggs, newborn chicks and juvenile AC were used to study the tissue structure of female gonads. Sections of ovaries were prepared and examined using various histological techniques including Hematoxylin and Eosin, Periodic acid-Schiff and Masson's trichrome. Semi-thin and ultra-thin sections of ovary in newly-hatched chicks were prepared for study by electron microscope. The study revealed asymmetry between the left and right ovaries, with a larger left ovary. The functional left ovary exhibited a cortex and medulla, containing somatic and germ cells, with an increase in germ cell number, size and volume leading to cortex thickening. Meiosis division of germ cells and oocyte formation were observed with pre-follicular cells surrounding them. Electron microscopy revealed mitochondria and desmosome cell junctions in germ cells. Our study provided insights into tissue changes in ovaries and germ cells at different developmental stages of AC embryos, newly-hatched chicks and juvenile AC. The results suggested that cortex thickening and germ cell mitochondria density could be used as hallmarks of healthy AC maturity under normal physiological conditions. Further research should explore the impact of growth factors, hormones and environmental factors to unravel avian ovarian development complexities and improve AC reproductive biology knowledge.

Abstract Exposure to extreme temperature conditions such as occurs in certain occupations is known to induce male infertility. In humans and most of the mammals, it has been shown that whole-body heat stress (HS) decreases fertility and produces defective embryos. Hence, the present study aimed at gaining some insights into the mechanisms producing defects after HS. In the present study, 56 mature male Wistar rats were randomly categorized into eight groups (n = 7), including group 1: Control, groups 2: Bioactive peptides (BPs; 10.00 mg kg^-1), groups 3, 4, and 5: Heat-stressed (37.00, 39.00, and 43.00 ˚C for 20 min, respectively), and groups 6, 7, and 8: Heat-stressed along with BPs (10.00 mg kg^-1), respectively. All treatments were administered orally once per day. The HS was induced through the immersion of rat scrotums in a water bath. After 45 days, rats were sacrificed and left testes were removed, fixed, and used for histological and immunohistochemical studies. Harvested right testes were also used for oxidative stress assessments and molecular analyses. Heat stress increased testicular tissue damage, elevated oxidative stress and reactive oxygen species production, and increased germ cells apoptosis, p53 and caspase 3 expressions, and Bax/Bcl-2 ratio. Treatment with BPs as a substance with anti-oxidant properties ameliorated the damage caused by HS. The results of this study highlight the protective role of BPs in the reproductive tract under HS. Bioactive peptides may have potential function against testicular tissue oxidative stress and apoptosis.

Abstract This study aimed to investigate the effects of zoledronic acid (ZA) and antibacterial CM11 peptide on the osteoinduction and antibacterial properties of bioactive glass (BG). The bioactive glass/gelatin (BG/Gel) composite was synthesized using the sol-gel method. The 2-x minimum inhibitory concentration of the peptide and 4.00 mg mL^-1 of ZA were added to the BG/Gel during fabrication. The BG/Gel composite morphological and structural characteristics and anti-bacterial activities were analyzed using Fourier transform infra-red spectroscopy, scanning electron microscopy and disk diffusion test, respectively. The release of the peptide and ZA from BG/Gel was measured using ultra-violet spectroscopy. After 14 days, the effects of the peptide/ ZA-containing BG/Gel (PZ-BG/Gel) on the growth and differentiation of mesenchymal stem cells were evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide, calcium and alkaline phosphatase assays, immunocytochemical staining for osteocalcin (OCN) and real-time polymerase chain reaction for OCN, type I collagen, bone morphogenetic protein 2 and Runt-related transcription factor-2 genes. The disk diffusion test showed the anti-microbial activity of the scaffold against multi-drug-resistant isolates of Pseudomonas aeruginosa and Staphylococcus aureus. Analyses showed a significantly higher level of stem cells differentiation into the osteo-genic cells in PZ-BG/Gel scaffold compared to BG/Gel scaffold alone. Accordingly, osteoblast markers were significantly increased in comparison with the control. In conclusion, the osteo-induction and antibacterial properties of BG-based scaffold can be improved using ZA and CM11.

Abstract Organisms have evolved defense mechanisms to protect themselves from stressful conditions. The expression of heat shock proteins is considered a valid indication of protection from the adverse effects of hostile conditions. In this study, we used immunohistochemistry to investigate the seasonal effects of some abiotic factors on heat shock protein 70 and 90 (HSP70 and HSP90) expression in the liver, gills, and muscle tissues of 24 Common carp (Cyprinus carpio) caught in Karataş Lake (Burdur, Türkiye) using gillnets of various mesh sizes. We also measured some physicochemical parameters on-site at sampling time and took water samples for further analyses of other physicochemical parameters and heavy metals. Immunostaining for HSP90 was stronger than for HSP70 in both liver and gill samples. Liver and gill structures exhibited significant seasonal differences in HSP70 and HSP90 immunoreactivity, and the same was true for immunostaining for HSP70 and HSP90 in muscle samples. Some physicochemical properties seemed to vary considerably between seasons, with Fe, Mn, and Zn levels tending to exhibit changes throughout the seasons. However, these levels were considered acceptable for human health. In conclusion, this study suggests that substantial changes in HSP70 and HSP90 expression may be essential for seasonal adaptation and tolerance. Further research on fish HSPs would greatly contribute to aquaculture, which is essential for meeting food requirements.

Abstract Methotrexate (MTX) as a chemotherapeutic agent, has adverse effects on reproductive organs by enhancing oxidative stress. In this study, the protective effects of Cornus mas fruit extract (CMFE) against MTX side effects were evaluated. Forty-eight mature male NMRI mice were divided into six groups: group 1 (control) received 0.10 mL per day of normal saline intraperitoneally (IP), group 2 received MTX (20 mg kg^-1 per week, IP), group 3 received MTX along with CMFE 250 mg kg^-1 per day by oral gavage, group 4 received MTX along with CMFE 500 mg kg^-1 per day by oral gavage, group 5 received MTX plus 1000 mg kg^-1 per day of CMFE by oral gavage, and group 6 received 1000 mg kg^-1 per day of CMFE extract, orally. All animals were treated for 35 consecutive days. Thickness of testicular capsule and germinal epithelium and diameter of seminiferous tubules were measured. Intra-cytoplasmic levels of carbohydrate, unsaturated fatty acid (UFA) and alkaline phosphatase were assessed. Serum level of testosterone and testicular total antioxidant capacity (TAC) were also evaluated. The results demonstrated that MTX administration caused morphometrical parameters except the thickness of testicular capsule were significantly different in comparison to control group and decreased cytoplasmic concentration of carbohydrate in the first three layers of germinal epithelium and increased the UFA levels. Contrarily, CMFE ameliorates the condition. Moreover, CMFE increased testosterone level and increased the MTX-reduced TAC level. In conclusion, it was revealed that CMFE decreased the cellular atrophy by controlling the energy substrate utilization based on lipids and carbohydrates via provoking the testicular antioxidant status.

Abstract In order to conduct this study, eight adult turkey heads were obtained. Pituitary glands were harvested following cranial bones removal and examined morphologically and anatomically as well as topographically. Then, tissue sections were prepared and stained using Hematoxylin and Eosin, Alcian blue, orange G and periodic acid-Schiff staining techniques. The results showed that turkey pituitary gland as a pea-sized structure is located in the ventral part of the cerebrum and composed of adenohypophysis and neurohypophysis parts. Moreover, histological analyses revealed that sinusoids are well-developed at the distal part of the adenohypophysis and irregular masses of endocrine cells exist among them. Distributions of basophilic cells in the distal part of adenohypophysis were significantly higher than those of other endocrine cells, while the acidophilic cells had the lowest distribution. Lower and higher numbers of chromophobe cells were also found compared to those of basophilic and acidophilic cells, respectively. These findings were mostly similar to the other birds’ pituitary gland anatomical and histological features, but there were also differences in cellular elements distributions along with infundibular cavity topography.

Abstract Previous studies have reported many discrepancies about the best type and concentration of cryoprotective agents (CPAs) and biological variability among various pre-antral follicle classes after cryopreservation of ovarian tissue. The aim of this study was to investigate the impacts of some synthetic polymers on histological characteristics of different types of pre-antral follicles after bovine ovarian tissue vitrification. From each bovine ovarian pair, fragments were recovered and immediately fixed for analysis (fresh control group) or submitted to vitrification (sucrose, X-1000, Z-1000 and polyvinylpyrrolidone groups), either followed by in vitro culture for 1 or 5 days. In this case, although, the addition of X-1000 resulted in greater percentages of normal follicles for almost all pre-antral follicle classes compared to those of other groups, there are some exceptions. These results indicate that the inclusion of polyvinylpyrrolidone in the freezing media can improve the morphology of the post-warmed transitional follicles and cultured primordial follicles on day five more than other CPAs. According to the results of this study, it can be concluded that although ovarian tissue cryopreservation is often performed to preserve the primordial follicles, by choosing the best combination of permeating and non-permeating CPAs (synthetic polymers), more advanced stages of bovine pre-antral follicles, transitional, primary and secondary follicles, may also survive the cryopreservation process.

Abstract The aim of this study was to find a proper method for improvement of ischemic condition in the rat hind limb and also to observe the efficacy of cell engraftment with alginate/gelatin three-dimensional scaffolds. Eighteen male Wistar rats weighing 200 to 250 g were randomly divided into three groups (n = 6) including a) ischemia group; in which femoral artery was removed after ligation at the distance of 5 mm, b) scaffold group; in which hydrogel scaffold was added to the site of transected femoral artery and c) test group; in which in addition to hydrogel scaffold, mast cells (MCs) were also added (1 × 10⁶ cells). Analysis of capillary density, artery diameter, histomorphometric parameters and immunohistochemistry in transected location were done on day 14 after femoral artery transection. The average number of blood capillary was significantly higher in the test group than other groups. Also, the average number of medium and large blood vessels was significantly higher in the test group compared to ischemia and scaffold groups. Application of MCs through the use of hydrogel scaffolds (alginate/gelatin) can be considered as a new approach in the application of stem cells for therapeutic angiogenesis under ischemic conditions which can improve the angiogenesis process in patients with peripheral artery diseases.

Abstract The aim of this study was to investigate the dorsal surface of the long-eared hedgehog tongue using scanning electron microscopy. The tongue of the long-eared hedgehog is rectangular-shaped with an elongated body and a widened root and a marked deep median groove can be seen on its dorsal surface. A characteristic feature of the lingual root is presence of two huge laterally situated folds. These anatomical structures have never been described with regard to other small mammals studied so far. According to their anatomical appearances, the lingual papillae can be distinguished as filiform, conical, fungiform, circumvallate and foliate papillae. The filiform papillae covering the body of the tongue are longer and wider than those on its apex and have an apparent fork-like appearance. Fungiform papillae are evenly distributed on the dorsal surface of the apex and body of the tongue. The triangular area of the lingual root contains small caudally directed conical papillae with single processes. Foliate papillae are situated on both lateral surfaces of the lingual root medial to the huge lateral lingual folds as three large obliquely situated parallel folds. There are three circumvallate papillae, two of which are obliquely situated on both sides of the rostral part of the lingual root, while the third one is situated in the midline of the caudal part of the lingual root. The results show that the tongue structure of the long-eared hedgehog is more complex in comparison with other mammals which is related to its phylogeny and feeding habits.

Abstract This study evaluated the possible protective effect of royal jelly (RJ) on sperm parameters and sperm malondialdehyde (MDA) concentration and in vitro fertilizing potential in nicotine (NIC) exposed male mice. Thrtiy-six male BALB/c mice were randomly divided into six groups (n = 6). Group 1 received normal saline, group 2 received 100 mg kg^-1 per day RJ, groups 3 and 4 received NIC at doses of 0.50 and 1.00 mg kg^-1 per day, respectively and groups 5 and 6 received NIC at doses of 0.50 and 1.00 mg kg^-1 per day, respectively plus RJ. Caudal epididymal sperm characteristics, lipid peroxidation and in vitro fertilizing capacity and embryo development were evaluated after 35 days. The NIC treatment caused a significant decrease in sperm motility and viability and fertilization rate along with poor blastocyst formation and increased sperm DNA damage and MDA levels. Moreover, the incidences of chromatin abnormality in spermatozoa were significantly higher in NIC-exposed mice than those of control. Nevertheless, RJ treatment improved sperm parameters and in vitro fertilization outcome as well as sperm lipid peroxidation level. Data from the current study suggest that RJ has a potential repro-protective action against NIC-induced sperm abnormalities and embryotoxicity in mice.

Abstract The objective of the present study was to investigate the clinical and histopathological effects of intravitreal injection of pentoxifylline (PTX) the management of an experimental model of uveitis. Fifty-two rabbits were divided randomly into six intravitreal treated groups as below: 1) Balanced salt solution (BSS), 2) Salmonella typhimurium lipopolysaccharide endotoxin (LPS) + BSS, 3) LPS + PTX 100 μg, 4) LPS + PTX 500 μg, 5) BSS + PTX 100 μg and 6) BSS + PTX 500 μg. Inflammation was evaluated by clinical examinations using slit lamp on days 1, 3, 5 and 7 post injections and histopathological examinations were also performed at the end of the study. Clinical examinations demonstrated a statistically significant difference between group 1 and group 2 on day 5 and day 7. Moreover, the comparison of clinical severity scores of group 1 with groups 3, 4, 5 and 6, on third, fifth and seventh post-injection days showed statistically significant differences. The mean histopathological inflammation intensity score in groups 5 and 6 was significantly higher than group 1. The mean histopathological inflammation intensity score in groups 3, 4, 5 and 6 was significantly higher than group 2. Intravitreal injection of PTX in an experimental model of uveitis in rabbits not only does not reduce inflammation but also leads to inflammation when used alone or in combination with LPS.

Abstract Cyclophosphamide (CP) is known to reduce fertility. The protective effects of Spirulina plantesis (SP) against CP-induced testicular toxicity were investigated. Male Wistar rats were categorized into eight groups (n = 7). Four groups of rats were administered CP at a dose of 5 mg in 5 mL distilled water kg^-1 per day orally. Two of these groups were received SP (500 and 1000 mg kg^-1 per day) orally after CP administration. One of these groups was also received vitamin E (100 mg kg^-1 per day) intraperitoneally. A vehicle treated control group, two SP control groups (500 and 1000 mg kg^-1 per day) and a vitamin E control group were also included. Body and testes weights, sperm count, serum levels of glutathione peroxidase (GPx), malondialdehyde (MDA), histological and histomorphometric alternations in testes were investigated after four weeks. The CP-treated group exhibited significant decreases in the body and testes weights and spermatogenic activities. Several histological alterations were observed in this group. The CP treatment caused a significant reduction in sperm count, in serum level of GPx, as well increased serum concentration of MDA. The SP co-administration caused an increase in GPx serum level, a decrease in MDA serum level and improvements in histological and histomorphometric alternations. Vitamin E co-treatment showed partial recovery in above-mentioned parameters. These results suggest that SP due to a reduction in oxidative stress has more effective protection against CP-induced reproductive damages in rat than vitamin E.

Abstract Chlorpyrifos (CPF) is a broad spectrum organophosphate pesticide used for agricultural health purposes. Its principal mechanism of toxicity is the inhibition of acetylcholinesterase. The purpose of present study was to investigate the effects of CPF on testicular tissue and sperm parameters in male rats. Thirty-two healthy male rats were divided into two groups: a CPF-exposed group and a control-sham group. Control-sham group received corn oil (0.20 mL per day). The CPF was administered orally to male rats at 37 mg kg^-1 BW for 45 days to evaluate the reproductive toxicity. In all rats, sampling for histological and sperm analyses was performed on days 5, 15, 30 and 45. The CPF caused a significant (p < 0.05) decrease in sperm count, viability and motility and increased immature sperms and DNA damage in sperm cells. Light microscopic analyses revealed increased arrested spermatogenesis, negative tubular differentiation and repopulation indexes and decreased Leydig cells number. These findings indicate that CPF has adverse effects on sperm cells and reproductive system of male rats.

Abstract Nicotine (NIC) adversely influences male reproductive system. Achillea millefolium (Achm) as a medicinal plant is highly regarded for its antioxidant and anti-inflammatory properties. The present study was conducted to assess whether Achminflorescences alcoholic extract could serve as a protective agent against reproductive toxicity in NIC-exposed male rats. Adult male rats were randomly divided into six groups. Two groups received NIC at doses of 0.20 and 0.40 mg kg^-1 per day in 0.50 mL sterile distilled water for 48 days intraperitoneally, respectively. The further two groups received NIC at doses of 0.20 and 0.40 mg kg^-1 per day in 0.50 mL sterile distilled water for intraperitoneally along with Achm extract at a dose of 1.20 g kg^-1 per day in 1 mL sterile distilled water orally for 48 days, respectively. A vehicle treated control group and an Achm-only treated group were also included. The NIC-exposed groups showed significant reductions in epididymal sperm count, motility, viability and serum levels of FSH, LH and testosterone as well as testicular antioxidant capacity. Moreover, the incidence of apoptosis and abnormality in spermatozoa along with testicular malondialdehyde and total nitrite levels were significantly higher in NIC-treated rats. The above-mentioned parameters were restored to near normal levels by Achm co-administration. These findings indicated thatAchmmay partially be protective against NIC-induced testicular toxicity.

Abstract Curcumin has been found to be very efficacious against many different types of diseases. However, the major disadvantage associated with the use of curcumin is its low systemic bioavailability. In the present study the protective effects of curcumin-loaded poly lactic-co-glycolic acid nanoparticles (nanocurcumin) against mono-iodoacetate-induced osteoarthritis in rats was investigated. Mono-iodoacetate was injected into right knee joints to induce osteoarthritis. In experimental groups, 14 days after injection of mono-iodoacetate, curcumin (200 mg kg^-1) and nanocurcumin (200 mg kg^-1) were gavaged, respectively, for two weeks. Then the rats were sacrificed and the right knee joints were removed and fixated in 10% formalin for histological assessments. Cellularity and matrix staining were significantly increased in articular cartilage of curcumin-treated animals compared to mono-iodoacetate group (p < 0.01). These effects were significantly (p < 0.01) more in nanocurcumin-treated animals. These results suggested that administration of nanocurcumin prevented the structural changes of articular cartilage in mono-iodoacetate modelofosteoarthritis in rats.

Abstract The objective of this study was to highlight the postnatal development of the uterine tubes of the West African Dwarf goat from birth to 28 weeks of age by gross examination and light microscopy. There was a caudal migration of the paired uterine tubes from behind the paired kidneys at birth to the pelvic inlet at week 8 of age. Each uterine tube exhibited three segments namely; infundibulum, ampulla and isthmus. A marked flexure, the utero-tubal junction, was the point at which the uterine tubes joined the uterine horns. The length and absolute weight of the uterine tubes increased from 4.95 ± 0.28 cm and 0.02 ± 0.01 g at birth to 14.98 ± 2.79 cm and 0.22 ± 0.03 g at week 28 of age, respectively. The mucosa of the infundibulum and the ampulla showed long, branched and anastomosing primary, secondary and tertiary mucosal folds which decreased in height towards the isthmus. The mucosal folds within the isthmus were short and lacked the anastomosing pattern. The epithelia of all three segments were pseudostratified columnar. Numerous secretory blebs and extruded nuclei became apparent from week 16 of age. The thickness of the tunica muscularis varied with the segments.