Immunohistological investigations of autopsied carotid bodies and their application to diagnosing strangulation

Vasoactive Intestinal Polypeptide in the Carotid Body-A History of Forty Years of Research. A Mini Review

Vasoactive intestinal polypeptide (VIP) consists of 28 amino acid residues and is widespread in many internal organs and systems. Its presence has also been found in the nervous structures supplying the carotid body not only in mammals but also in birds and amphibians. The number and distribution of VIP in the carotid body clearly depends on the animal species studied; however, among all the species, this neuropeptide is present in nerve fibers around blood vessels and between glomus cell clusters. It is also known that the number of nerves containing VIP located in the carotid body may change under various pathological and physiological factors. The knowledge concerning the functioning of VIP in the carotid body is relatively limited. It is known that VIP may impact the glomus type I cells, causing changes in their spontaneous discharge, but the main impact of VIP on the carotid body is probably connected with the vasodilatory effects of this peptide and its influence on blood flow and oxygen delivery. This review is a concise summary of forty years of research concerning the distribution of VIP in the carotid body.

Immunohistochemical Study of Dark and Progenitor Carotid Body Cells: Artefacts or Real Subtypes?

Postmortem changes occurring in human carotid body were simulated on the Wistar rat model. It was shown that light, dark, and pyknotic (progenitor) subtypes of human carotid body cells are an artifact and cannot be used in clinical practice to study the characteristics of various human diseases. The differences between the control group of healthy individuals and individuals with the various pathologies are most likely due to the different levels of premortal hypoxia that the tissue had been exposed to. Moreover, widespread antigens used in practice were divided into 2 groups by their tolerance to autolysis: stable and unstable ones. This can be useful for the development of immunohistochemical test algorithms for the diagnostics on autopsy material.

Histological examination of the carotid bifurcation in case of violence against the neck

The carotid body and carotid sinus are localized in the area of the carotid bifurcation and respond to pressure fluctuations in the arterial blood vessel system. In case of irritation or stimulation, nervous impulses can reflexively increase the ventilation or slow down the heart rate and blood pressure, respectively. The external stimulation of the carotid sinus by neck compression with subsequent bradycardia or asystolia, especially in pre-existing heart-disease, is discussed controversially in the literature. Histological examination of the tissue of the carotid bifurcation, particularly with regard to haemorrhage as an indication of tissue trauma, should be carried out in terms of simple and easy feasibility in routine diagnostics. In 20 cases of violence against the neck and additionally 82 cases of a control group without neck trauma and variable causes of death, the carotid bifurcations were examined histologically. Only in one case of violence against the neck haemorrhage was found, which suggested a direct trauma to the tissue of the carotid bifurcation, but evidence of lethal cardiac reflex was not found in any case.

Thyreoglobulin and violent asphyxia

The concentration of thyreoglobulin (tg) was determined for death caused by hanging, strangulation by ligature, and throttling. Cases of sudden death (traumatic aortic rupture, penetrating wounds of the heart) were used for comparison. The mean values in cases of hanging (149.9 +/- 202.3 ng/ml), strangulation by ligature (193.1 +/- 173.3), manual strangulation (561.6 +/- 173.9) are distinguishable from violent acute deaths (23.3 +/- 27.6) and living healthy individuals (17.3 +/- 16.1). By means of statistical comparisons, significant differences were found between throttling and strangulation by ligature and between throttling and hanging (adjusted P < 0.001). In connection with examination of the bodies high tg values can be regarded as a vital reaction in obstructive asphyxia.