Comparative study of the ultrastructural alterations in the pulmonary vessels of rats treated with alphanaphthylthiourea (ANTU) and ammonium sulphate

Abstract

A comparative study of the ultrastructural changes in rat pulmonary vessels was made in two different situtations of increased vascular permeability: one caused by alpha-naphthylthiourea (ANTU) and the other induced by ammonium sulphate (AS). AS had a more destructive effect on the capillaries but showed little alteration in vessels larger than capillaries. ANTU provoked milder ultrastructural lesions but acted on capillaries, arterial and venous structures. In both conditions intravenously injected carbon particles adhered to the vessel wall and leakage into the interstitial space was rarely seen despite the presence of endothelial gaps. It was concluded that ANTU and AS provoke different ultrastructural alterations and that pulmonary and systemic vessels react differently when undergoing changes in permeability.

Vascular damage in acute experimental leptospirosis of the guinea‐pig

“…Blebs, sloughing of the endothelium and platelet and leucocyte thrombi, are non-specific responses of lung vessels. They occur in other situations such as immunological pulmonary oedema ( B o b et al, 1973), pulmonary oedema induced by ammonium sulphate and alpha-naphthyl-thiourea (Hatakeyama and Shigei, 1968;Hayes and Shiga, 1970;Machado et al, 1977), snake venom induced vascular injuries (Almeida et al, 1977) and many other situations (Hurley, 1978). In all cases, these alterations indicate severe damage to the lung vessels.…”

Current views on the mechanisms of pulmonary oedema

“…It has been suggested that the pattern of fluid accumulation in interstitial tissues might result from fluid leakage from larger vessels within the interstitial space (Whayne and Severinghaus, 1968 ;Iliff, 1971). However carbon labelling studies on pulmonary oedema induced by either ANTU (Bohm, 1966;Cunningham and Hurley, 1972;Machado, Bohm and Padovan, 1977) or pyrrolizidine pyrroles (Hurley and Jago, 1975;Stoner, 1972 Plestina et al, 1977) show that in these types of pulmonary oedema leakage occurs from small vessels-arterioles, capillaries and venules within the alveolar wall (figs. 4 and 5).…”

“…This type of pulmonary oedema seems to be due to increased vascular permeability uncomplicated by concurrent hydrodynamic disturbances. Several ultrastructural and topographical studies have been made of ANTUinduced oedema (Terpitz, 1968;Cunningham and Hurley, 1972;Meyrick, Miller and Reid, 1972;PIestina and Stoner, 1972;Machado et al, 1977). All studies report minor but definite injury to pulmonary vascular endothelium with in non-fatal cases " regenerative " changes 24-48 hr later.…”

“…Terpitz (1968) and Cunningham and Hurley (1972) found that most labelling was in capillaries although venules were also affected. In subsequent studies Bohm claimed that all small vessels in the lung-arterioles, capillaries and venules are affected by ANTU (Bohm, 1973;Machado et al, 1977). These differences of opinion stem in large part from a failure to realise that not all carbon labelling in cleared specimens is indicative of increased vascular permeablity (Cotran, Suter and Majno, 1967).…”

“…aqueous ammonium sulphate solution induces almost immediately severe and often fatal pulmonary oedema, which is accompanied by obvious evidence of central nervous intoxication. The ultrastructural features of this type of pulmonary oedema have been studied by Hayes and Shiga (1970) and by Machado et al (1977). Both groups report injury to endothelial and epithelial cells in the alveolar wall and the presence of numerous blebs in the lumen of pulmonary capillaries.…”