Comparative study of platelet histamine and serotonin with their corresponding plasma oxidases in asthmatics with normals.

OBJECTIVE: Asthma is well controllable but non-curable disease. Exact pathophysiology involved is unresolved till today. Role of allergic hypersensitivity reaction in asthmatic on-set is well established. Present work is an effort to elucidate some basic points of unresolved pathophysiology of asthma taking platelets as marker. MATERIAL AND METHODS: A group of 52 normal human subjects in the age group of 20-60 years were studied for platelet histamine and serotonin levels and also for their plasma metabolising enzymes diamine oxidase (DAO) and monoamine oxidase (MAO). The data was collected for 79 asthmatic patients at different stages of asthma and accordingly were studied as four different groups of seventy nine asthmatics those were on regular treatment and were comfortable with drugs and were free from symptomatic attack formed gr. I; these (79) patients were followed-up during their symptomatic phase (gr. II) and same (79) patients immediately after their recovery from symptomatic stage studied as gr. III members. All the 79 asthmatic patients fall in gr. I, II and III in a serial manner i.e. all (n = 79) in each group. A separate group of thirty seven patients with known history of asthma but were symptom free and also off drugs for last 2-4 years formed gr. IV. RESULTS: Results showed mean platelet count in asthmatics at all four stages were in the normal range but were slightly low in comparison with normals. Both the enzymatic levels (DAO and MAO) in gr. I, II and III were significantly higher than normals but were same in the case of gr. IV patients. Low levels of platelet biogenic amines were observed in asthmatics (gr. I to gr. IV) than normals. CONCLUSIONS: Thus, study parameters showed significant difference in asthmatics and normals. Findings of the study have been utilized to understand unanswered hypersensitivity shown by the asthmatics over normal individuals (non-asthmatics).

Blood histaminase in phlyctenulosis.

Blood Histaminase estimations were done in 42 cases of phlyctenulosis and 25 normal subjects. Significantly higher level of blood Histaminase was found in patients of phlyctenulosis, which may be a consequence of its induction secondary to increased release of histamine in the early phase of disease.

Level of serum and renal histamine and diamine oxidase activity in lead acetate treated rats.

The levels of histamine and Diamine oxidase activity in renal tissue and serum were determined in lead acetate treated rats. The results show a significant lowering in the level of renal histamine with a rise in diamine oxidase activity in serum as well as in renal tissue.

Isolation and characterization of monoamine oxidase from hyperfunctioning human thyroid.

Human thyroid monoamine oxidase from hyperfunctioning thyroids was isolated and purified by separating the mitochondria by differential centrifugation followed by ultrasonication. The suspension containing the active enzyme from the DEAE-column, on passing through a Sephadex G-200 column gave three peaks corresponding to molecular weights of approximately 220,000, 23,000 and 4000 of which the component with molecular weight 4000 showed enzyme activity. The blood of the patients was analyzed for plasma MAO, RBC cholinesterase, plasma histaminase and plasma catecholamines. Histology and histochemistry of the thyroid tissues were also done. The data are examined from the point of view of the prevalent idea of the possible existence of MAO in multiple forms.