Effect of Methotrexate and Vitamin A on NOR Expression in the Lining Epithelium of Gastric Mucosa in Male Wistar Rats Reghunathan Deepthinath1, Bhat K Ramachandra2, Bairy K Lakshminarayan3, Murlimanju BV4,,*, Prasad AM1 1Department of Anatomy, Melaka Manipal Medical College, Manipal Campus, Manipal University, Manipal, Karnataka, India 2Department of Anatomy, Kasturba Medical College, Manipal University, Manipal, Karnataka, India 3Department of Pharmacology, Kasturba Medical College, Manipal University, Manipal, Karnataka, India 4Department of Anatomy, Kasturba Medical College, Manipal University, Bejai, Mangalore, Karnataka, India *Corresponding author email id: flutemist@gmail.com
Abstract Background and objective: The histopathology and expression of nucleolar organising regions (NORs) of gastric mucosa were studied after the administration of methotrexate (MTX) and vitamin A (VA). The objective was to test whether the argyrophylic nucleolar organiser region (AgNOR) count increases or decreases with different doses of MTX. The literatures on AgNORs suggest that there may be a possible association between AgNOR counts and disease transformation. MTX is one of the commonest drugs used in several diseases. It is interesting to hypothesise the numbers, shape and the distribution of AgNORs after the administration of MTX. Methods: Male Wistar rats aged 4 months, maintained in our institution, were used in the present study. The rats were divided into following groups, group I - control (saline treated), group II - animals treated with 8 mg of MTX, group III - animals treated with 10 mg of MTX, group IV - animals treated with 12 mg of MTX, group V - animals treated with VA (5,000 IU), group VI - animals treated with VA (5,000 IU) and MTX (12 mg). Results: It was observed that MTX treatment showed abrupted or incomplete surface epithelium in the gastric mucosa. The gastric pits were short and epithelium showed lightly stained nuclei and cytoplasm. When MTX was given along with VA, the VA minimised the severity of damage caused by MTX. The frequency of large-size NOR was reduced after treatment with MTX. However, the medium and small-size NOR count were increased. When treated with MTX and VA, NOR frequency increased and reached almost the level of the control group. Conclusion: The present study observed that large-sized NOR decreases numerically while medium and small sized NORs increases with the administration of MTX. We believe that the NOR fusion was affected by the MTX drug. Higher the dose of MTX, lesser the NOR count and lesser the irregularity of NORs. However, VA co-administration reduces the damage produced by MTX. We believe that findings of the present study might be useful in understanding the long-term effect of MTX and its adverse effects. Top Keywords Methotrexate, NOR, AgNOR, Histopathology, Vitamin A. Top |