The effects of histamine injection on the histochemistry of the guinea pig parathyroid gland.

Histochemical studies on the activity of some neuropeptides (PGP, CT, NPY, SP and betaE) and enzymes (AP, AlP, SDH and MAO) were performed on guinea pig parathyroid glands after injections of histamine, histamine receptor blockers and muscarinic receptor blocker. Under conditions of histamine shock, the immunoreactivity of CT and the reactivity of SDH and MAO were found to decrease together with an increase in the activity of betaE and AP. The reactions for SP, NPY, PGP and AlP did not change in any of the groups.