[The influence of pineal peptides on in vitro immunoglobulin secretion by Peyer's patches in rats].

The influence of the pineal peptides (1 mcg/ml) on immunoglobulin secretion by rat's Peyer's patches isolated from nonimmunized rats and from orally immunized by ovalbumin during 40 min incubation, was investigated. Using alpha- and beta-adrenoblockers--phentolamine hydrochloride (0.02 mg/ml) and anaprilin (0.6 mg/ml), respectively--the possibility of pineal peptides' effect on the gut secondary lymphoid organ' adrenoreceptors, was evaluated. Basic levels of immunized rats' control Peyer's patches secretory activity were 2.4--fold (p < 0.01) higher than those of non-immunized rats. The effect of pineal peptides on antibody-producing cells' secretory activity depended on Peyer's patches' functional condition. Application of pineal peptides led to a 35% (p < 0.05) increasing of immunoglobulin secretion by non-immunized rat Peyer's patches and to a 25% (p < 0.05) decreasing of antibody production by immunized rats lymphoid organs. These data suggest that the pineal peptides activation influence on Peyer's patches antibody-producing cells of nonimmunized rats connected with alpha-adrenoreceptors, and inhibiting action of these peptides on immunized rats lymphoid organs immunoglobulin secretion are not mediated through adrenoreceptors.