[The influence of aminostigmine on the parameters of nonspecific resistance and immune system of the organism upon acute poisoning of benzyl 3-quinuclidylate]

The results of experiments on outbred rats weighing 180 -240 g showed that the acute poisoning with benzyl 3-quinuclidylate decreases the parameters of nonspecific resistance of the organism, reduces the antibody production mainly to T-dependent antigens (sheep red blood cells), decreases the activity of natural killers and the antibody-dependent cell-mediated cytotoxicity, and suppresses the formation of delayed-type hypersensitivity. Aminostigmine partly inhibits the immunotoxicity benzyl 3-quinuclidylate.

Circulating antibodies against rat parotid gland M3 muscarinic receptors in primary Sjögren's syndrome

In this study we demonstrate that IgG present in the sera of patients with primary Sjögren's syndrome (PSS) could bind and activate muscarinic acetylcholine receptors (mAChRs) of rat parotid gland. These antibodies were able to inhibit in a non-competitive manner the binding of 3H-quinuclidinyl benzilate (QNB) to mAChRs of purified rat parotid gland membranes. Moreover, IgG from PSS could modify biological effects mediated by mAChR activation; i.e. decrease cAMP, increase phosphoinositide turnover without affecting cGMP. Atropine and 4-DAMP blocked all of these effects, and carbachol mimicked them, confirming the M3 subtype mAChRs mediated PSS IgG action. Neither binding nor biological effect were obtained with IgG from sera of normal women. The prevalence of cholinergic antibody was 100% in PSS, and was independent of Ro/SS-A and La/SS-B antibodies. It could be concluded that antibody against mAChRs may be another serum factor to be considered in the pathophysiology of the development of PSS.

Polyclonal anti-propylbenzilylcholine mustard antibodies selectively recognize labeled muscarinic receptors from rabbit brain

Polyclonal antibodies were produced in rabbits to propylbenzilylcholine mustard-bovine serum albumin (PBCM-BSA) conjugates. The antibodies selectively recognized and bound to an apparent single class of sites with high affinity for PBCM. The antibodies also demonstrated high to intermediate affinity for muscarinic ligands which have benzhydryl or dicyclohexane ring structures similar to PBCM. The antibodies had little or no affinity for ligands which lacked the double cyclohexane structure. Antibodies recognized muscarinic receptors specifically labeled with [3H]PBCM, but not unlabeled receptors, on immunoblots. These results suggest that the polyclonal antibodies produced in this study react specifically with the dicyclohexane structure on PBCM and that this antigenic determinant remains available for interaction with the antibodies, even when the ligand is bound to the receptor.