Search

Experimental calcification of the aorta, induced in rabbits by a single dose of 8 mg of dihydro-tachysterol (AT 10), represents an optimal model for studying vascular diseases caused by lipid and calcium deposition on the artery wall. This lesion may be treated with chelating agents and/or with glucagon. The effect of chelating agents and/or of glucagon on lipid and calcium deposition involving the aortic wall was studied in 12 adult white Flemish rabbits. The animals were divided into four groups and in each of them experimental calcification of the aorta was induced by AT 10. The first group did not receive any treatment and served as control. The second group received only ethylenediamine tetraacetic acid (EDTA) (120 mg daily). The third group received only glucagon (0.1 mg subcutaneously). In the fourth group, the glucagon (0.1 mg subcutaneously) was injected with EDTA (120 mg daily). The animals were killed 30 days after suspension of therapy. The aorta was rapidly harvested in its thoracic tract. The calcium content of the sclerosed aorta was determined by flame photometer, while the cytochemical detection of calcium was performed using N,N-Naphthaloyl-hydroxyl-amine. Lipid deposition was studied by Sudan black B staining. Usual laboratory staining (hematoxyline - eosine and Toluidin blue ) were used for detection of structural details. All morphological results were submitted to the quantitative analysis of images and statistical analysis. The results of the present study suggest that glucagon may play a role in the biochemical and morphological modifications usually found in atherosclerosis. In fact, macroscopic and ultrastructural evaluation of our morphological results suggest that the pathological changes observed may be restored by administration of glucagons and/or by chelating therapy., Scandinavian Journal of Laboratory Animal Sciences, Vol 31, No 4 (2004)

We have studied the cholinergic nerve fibers (CNF) of human uveoscleral tissue in normal and pathological conditions (intraocular pressure: (IOP) of various degrees ) and have performed a quantitative image analysis of CNF with the aim of studying an hypothetical association between IOP and the uveoscleral level of cholinergic neurotransmitter in nerve fiber of the enucleated human eyes. Eleven patients, previously enrolled in our medical protocols are affected by an increase of IOP of various degrees, were subjected to surgical enucleation of one eyeball for traumatic or neoplastic reasons and were the donors of samples of the uveoscleral tissue for CNF demonstration. The samples were also submitted to quantitative image analysis. An enzymatic activity, Acetylcholinesterase (AChe), is present in nerve fibers that innervate the human uveoscleral tissue. The AChe-positive nerve fibers represent about 7.2% of the observed area in normal conditions, while in patients with elevated IOP AChe activity is about 20.3% of the total observed area. The increase of AChe activity in our experiments, all performed under the same conditions, and therefore, with comparable results, may be related with the increase of IOP.