Abstract
As a result of histological and ultracytochemical investiga tions concerning the influence of thiamine and its disulfide derivative, thiamine tetrahydrofurfuryl disulfide (TTFD), on acetylcholinesterase (AChE) in extirpated guinea pig atria, it was found that there was a clear increase in the AChE activity by 10-4 M TTFD, a weak increase with 10-5 M and an extremely weak increase, about the same as that in only the nutrient (Locke's solution), with 5×10-4 M. However, with 10-4 M of thiamine there was a tendency for the activity to be the same degree as with Locke's solution alone or be even inhibited at times.
