Histidine

Histidine is an essential amino acid that serves as the precursor for the biogenic amine histamine, a key mediator in allergic reactions and gastric acid secretion, through a decarboxylation reaction catalyzed by histidine decarboxylase. Additionally, within enzyme structures such as acetylcholinesterase, histidine residues contribute to the catalytic triad, utilizing the imidazole ring to facilitate charge transfer and enhance the nucleophilicity of other active site residues, enabling substrate hydrolysis.

Adult

or not at all (Fig. 7.2G). It is noteworthy that. firing  twitching and fasciculations. Force of TILSTIGMIN 15 mg tab, 0.5 mg/ml in 1 ml and 5 ml inj.. 9.Dose 0.5–1 mg oral/parenteral 0.5–2.5 mg i.m./s.c.. 0.1–1.0% eye drops 15–30 mg orally. DISTINON, MYESTIN 60 mg tab; 1–3 tab TDS.