Involvement Of Potassium Channels In The Release Of Various Hormones
The present investigation was taken up to study the effect of long term treatment (30 days) of various potassium channel openers and blockers on serum insulin, glucose, T3, TSH and plasma cortisol in rats. Treatment with cromakalim for 30 days produced a significant decrease in serum insulin levels in rats. However, treatment with pinacidil and glibenclamide produced a significant increase in serum insulin levels. KRN 2391 did not produce any effect on serum insulin levels. Glucose levels were decreased significantly only with glibenclamide and no significant alteration in serum glucose levels was observed with any of the potassium channel openers. Serum T3 levels were significantly increased with cromakalim and glibenclamide. However no significant alteration in serum T3 levels was observed with pinacidil and KRN 2391. Serum TSH levels were significantly decreased with pinacidil. No significant alteration was observed in serum TSH levels by other potassium channel modulators. Serum cortisol levels were significantly decreased with all the three potassium channel openers while glibenclamide did not produce any significant change in serum cortisol levels. Our data suggest that potassium channels may be involved in the release of hormones other than insulin. It also indicates that there is involvement of different types of potassium channels in the action of different potassium channel modulators.