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[Ultrastructure of rabbit myocardium in experimental histamine shock]
Abstract:
The ultrastructure of rabbit myocardium was studied after experimental histamine release by Polymyxin-B-sulphate. As soon as 15 minutes after the histamine release mitochondria and sarcoplasmic reticulum showed alterations with appearance of lysosomes and partial destruction of contractile structures. The sarcolemm formed blistered protrusions with simultaneously expelled cytoplasmic elements. Whereas intramural vessels were inconspicuous, the pericapillar spaces showed a considerable enlargement. On the basis of these findings, we suppose that the changes were induced on the one hand by the increase of the permeability of capillaries produced by histamine and, on the other one, by local and general ischemia as a consequence of shock.
Insights
Experimental histamine release in rabbit myocardium caused rapid ultrastructural damage, including mitochondrial and sarcoplasmic reticulum alterations, and capillary changes, suggesting histamine-induced permeability and ischemia contribute to shock.
Area of Science:
- Cardiovascular Biology
- Cellular Ultrastructure
- Pharmacology
Context:
- Investigating the immediate effects of histamine release on cardiac tissue.
- Utilizing Polymyxin-B-sulphate to induce experimental histamine release in rabbit myocardium.
- Examining the ultrastructural changes at the cellular and subcellular levels.
Purpose:
- To elucidate the ultrastructural alterations in rabbit myocardium following experimental histamine release.
- To identify the specific cellular components affected by histamine-induced shock.
- To correlate observed ultrastructural changes with potential pathophysiological mechanisms.
Summary:
- Histamine release induced rapid myocardial ultrastructural damage within 15 minutes.
- Observed alterations included mitochondrial and sarcoplasmic reticulum damage, lysosome formation, and contractile structure destruction.
- Sarcolemmal blebbing and expulsion of cytoplasmic elements were noted, alongside pericapillary space enlargement.
Impact:
- Provides insights into the rapid cellular mechanisms of histamine-induced cardiac injury.
- Highlights the role of increased capillary permeability and ischemia in myocardial damage during shock.
- Contributes to understanding the pathophysiology of cardiovascular responses to histamine release.