rabbit nasal mucosa under the effect of intranasal insulin: histological study

ABSTRACT

The histopathological changes occurred in the rabbit mucosa under the effect of a conventional intranasal humanized insulin preparation [NI], given a properly calibrated dose, were studied. The duration of administration was one week [6 rabbits SG1], 2 weeks [6 rabbits, SG2] and 4 weeks [6 rabbits, SG3]. Another three comparable groups [EG1, EG2 and EG3], each composed of three rabbits which received the enhancer alone intranasally for the same durations, respectively, were alone studied. The changes encountered in the nasal mucosa of the studied groups were compared with the control mucosa supplied by three normal rabbits. The reported changes were related to the period of exposure. On more prolonged exposure, as in SG3, the outst and ing features were abrupt surface keratinization, hypertrophy of the mucosal nerve bundles, hyperplasia of the gl and ular units, and perivascular edema. In comparison with the control nasal mucosa no changes could be detected in the corresponding EG1, EG2 and EG3. Thus, these changes were induced by the given insulin and attributed to its local antigenic and /or chemical irritation property rather than a metabolic one. Provocation of severe pain by NI was also suggested on prolonged administration