PLASMA GALANIN IMMUNOREACTIVITY IN THE RAT AFTER SWIMMING

The purpose of our experiment was to study plasma immunoreactive galan in in the rat after swimming. Four groups of rats were used. At rest, one group was studied after an intravenous injection of D-glucose whil e another group received a corresponding saline injection. The two rem aining groups, treated respectively with glucose and saline, were inve stigated after a 30-min swimming session. After 30 min of rest in thei r respective cages, or after swimming, the animals were anesthetized f or immediate blood sampling. The main observation was that plasma gala nin was higher after swimming than after rest only in glucose-treated rats, in the vena cava (11.82 +/- 2.90 vs. 5.05 +/- 1.65 pM) and the p ortal vein (15.75 +/- 3.74 vs. 6.58 +/- 1.75 pM). Both saline-and gluc ose-treated groups had a significant increase of plasma norepinephrine from rest to swimming in the vena cava. A decrease of plasma insulin was observed in the portal Vein of exercised glucose-treated rats, whi le plasma glucose was higher in the portal vein of this group. In conc lusion after swimming, plasma galanin level was increased only in gluc ose-treated rats. A significant correlation was also observed between plasma galanin and glucose (r = 0.69, p < 0.01), suggesting that the p resence of glucose is necessary to induce galanin liberation during ex ercise. (C) 1997 Elsevier Science Inc.