• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.131-137
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• 2021

The aim of the study was to observe the influence and related mechanism of histamine and its analogues used for hypersensitivity tests and used as an indicator of impurities in drugs on the tissue-specific intestinal contraction. Intestinal contraction includes the activation of thick or thin filament regulation. However, there are few reports addressing the question whether this regulation is involved in histamine-induced regulation. We hypothesized that histamine plays a role in tissue-dependent regulation of intestinal contractility. Denuded ileal/colonic longitudinal and circular muscles of male rats were used and isometric contractions were recorded using a data acquisition system. Interestingly, histamine alone didn't increase the contraction of the circular muscle but increased the contraction of the longitudinal muscle. Histamine together with atropine (M3 receptor antagonist) didn't inhibit the contraction of the longitudinal and circular muscle. Therefore, histamine alone and together with atropine increases the ileal longitudinal muscle contraction suggesting that additional mechanisms (decreased receptor density, postreceptor signaling or distribution of agonists) might be involved in the regulation of ileal muscle contractility. In conclusion, histamine and/or atropine has some effect on the regulation of the longitudinal contractility regardless of M3 receptor and the simpler test would be preferred as the drug impurity test compared to more complicated tests.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.165-172
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• 1995

A transmission electron microscopic study was performed on the ultrastructure of the tegumental layer of GymophoLloines seoi (Digenea: Gymnophallidae) metacercarlae and adults. The metacercariae were obtained from naturally infected oysters, Crcssosoea gigas, and the adults from experimentally infected C3H mice. The tegumental layer generally revealed a small number of foldings, numerous small vacuoles, sines, and muscle bundles. Beneath the muscle layer, nuclei of the tegumental cells were located. There was little difference in the structure of the tegument between the metacercariae and adults. The oral sucker, having well-developed muscle layers, showed a similar structure to the ventral sucker except numerous foldlngs in the ventral sucker. The ventral pit was surrounded by a thin spcpiu layer, where a number of microtubules and mitochondria were seen. Around the ventral pit located well-developed circular and longitudinal muscles. The results showed that the ultrastructure of the tegumental layer of G. seoi metacercariae and adults revealed little difference from other trematodes in general. The ventral pit, a peculiar structure of this trematode, seems to function as a sphincter or an accessory adhesive organ.