| Popis: |
The gastric morphology of the white-tailed rat M. albicaudatus - was described in detail. The bilocular hemiglandular stomach consists of a papillated corpus, non-glandular PGP and glandular antrum. The antrum contains cardiac, fundic and PJ loric glands (suggesting limited glandular reduction during gastric evolution) while the FCE and PGP are lined with orthokeratin. The corpal papillae, which increase surface area for microbial attachment, have undergone a different type of keratinisation called physiological hyperkeratosis. Streptococci, Lactobacilli and unidentified anaerobic bacilli (which colonise papillary microhabitats) are autochthonous in the stomach of M. albicaudatus but P. vulgaris and Ps. flourescens are probably autochthonous. Early gastric development is innate but the rapid development of PB into papillae between 15 and 17 days suggests the presence of allogenic growth stimuli: possibly mechanical abrasion by solid food, low chalone concentration in the papillary basal cells and the influence of the APB. Stimulation by VFA presence, however, is unlikely due to the low concentration of these acids in the stomach (Summary, p. 225) |
