Phytomitogen induced changes in levels of inositol phosphates in the bovine lymphocytes.

The changes in levels of inositol phosphates and phosphoinositides were studied in the bovine lymphocytes, in response to phytomitogens (lectins)-concanavalin A (con A) and phytohaemagglutinin (PHA). Addition of con A and PHA resulted in a rapid increase in the cpm of total inositol phosphates (from 8599 +/- 100 cpm/2 x 10(6) cells to 11228 +/- 126 cpm/2 x 10(6) and 9758 +/- 100 cpm/2 x10(6) cells, respectively) at 1 min after mitogen stimulation. There was a concomitant decrease in the phosphatidylinositol levels at 1 min, which continued up to 5 min. At 1 min of stimulation, inositol diphosphate fraction exhibited maximum increase, as compared to inositol mono- and triphosphates, suggesting that it contributed the most towards the overall increase in the total inositol phosphates levels. Results suggest that bovine lymphocytes respond to phytomitogens with a rapid turnover of phosphoinositides.