1.
Thörne, Johan, et al.
(author)
Effect of ticlopidine and prostaglandin E on endotoxin-induced pulmonary platelet sequestration in vivo
1986
In: Circulatory Shock. - 0092-6213. ; 20:1, s. 61-69
Journal article (peer-reviewed) abstract
Prostaglandin E1 has earlier been shown to decrease pulmonary platelet trapping (PPT) following shock. This experiment was performed to evaluate a new method to study PPT in vivo, and to study the effect of prostaglandin E1 and a new antiplatelet drug (ticlopidine) on PPT in rabbits after i.v. administration of endotoxin. Following platelet labeling with In-111, the rabbits were placed under a scintillation camera for continuous measuring of the activity distribution for 40 minutes. The first five minutes represented reference values, whereafter endotoxin E. coli was injected i.v. The following 2-4 minutes showed a sudden increase of radioactivity over the lungs and a simultaneous decrease over the heart, indicating PPT in the nontreated animals, followed by a slow decrease to almost preshock values during the following 30 minutes. Animals receiving prostaglandin E1 showed a significantly lower activity peak in the lungs after the administration of endotoxin, while the corresponding peak in ticlopidine-treated animals did not differ from that seen in the nontreated animals. In all groups, endotoxin caused a decrease in platelet count, but it was significantly lower in the PGE1-treated animals. The results have shown that this diagnostic model for PPT is reliable and may be used for evaluation of the effect on platelet aggregation in vivo of different drugs
2.
Blomqvist, S, et al.
(author)
Early post-traumatic changes in hemodynamics and pulmonary ventilation in alcohol-pretreated pigs
1987
In: Journal of Trauma. - 0022-5282. ; 27:1, s. 40-44
Journal article (peer-reviewed) abstract
Time relations among trauma, pulmonary and systemic circulation, and lung function were studied in pigs. Eleven animals (b.w. 25-30 kg) were investigated under balanced anesthesia. Ventilation was mechanically controlled. Hemodynamics, pulmonary ventilation, and gas exchange were serially recorded. Seven animals were pretreated with 40% ethanol in saline and four with saline only. Ninety minutes after the ingestion of alcohol or saline, the animals were subjected to a standardized soft-tissue trauma. Cardiac output decreased significantly 2 minutes after trauma and remained low in both groups throughout the observation period of 30 minutes. Pulmonary vascular resistance was significantly increased in the alcohol-pretreated group but was virtually unchanged in the control animals. Systemic vascular resistance was similarly reduced in the two groups. Total compliance was somewhat lower in alcohol-pretreated animals and 10 minutes after the trauma arterial oxygen tension was significantly lower in the alcohol group than in control animals. Carbon dioxide elimination was reduced after trauma in both groups. It is concluded that pulmonary vascular response increased and that total pulmonary compliance is somewhat decreased shortly after trauma in the alcohol group while gas exchange is almost unchanged. The results indicate a negative interaction between alcohol and trauma
3.
Svensson, Henry, et al.
(author)
Laser Doppler flowmetry during hyperaemic reactions in the skin
1988
In: International journal of microcirculation, clinical and experimental. - 0167-6865. ; 7:1, s. 87-96
Journal article (peer-reviewed) abstract
Laser Doppler flowmetry (LDF) was used to study skin blood flow in the finger tip and on the dorsum of the hand in healthy volunteers. Vasodilatation in the finger tip was induced by immersing the arm in water at 42 degrees C, and vasodilatation in the dorsum of the hand by intracutaneous injection of dihydralazine. Simultaneous measurements were performed using venous occlusion plethysmography (finger tip) and 133Xe clearance (dorsum of hand). Three output signals from the laser Doppler flowmeter were recorded. The LDFPf-1 value is linearly related to the blood flow, provided the concentration of blood cells in the scattering volume is low. The LDFPf-2 value is generated by a signal processor designed to give linearity even at higher concentrations of moving blood cells (CMBC), the latter quantity being reflected by the CMBC value. During vasodilatation by immersion, all laser Doppler values from the finger tip increased but less than the total finger blood flow as measured using venous occlusion plethysmography. Intracutaneous injection of dihydralazine in the dorsum of the hand caused markedly increased CMBC values and the increase in LDFPf-2 was significantly greater than that of LDFPf-1. The increase in 133Xe clearance was less pronounced. The results indicate that capillary blood flow as well as blood flow in vessels below the capillary level contribute to the Doppler signal. However, flow through the arteriovenous shunts in the finger tip seems to be only partially registered by the laser Doppler technique. The higher the CMBC value, the more obvious is the difference between LDFPf-1 and LDFPf-2 values. When using laser Doppler flowmetry, the addition of CMBC value registration may be helpful in clarifying changes in microvascular blood flow.
4.
Widner, Håkan, et al.
(author)
Scintigraphic method to quantify the passage from brain parenchyma to the deep cervical lymph nodes in rats
1987
In: European Journal of Nuclear Medicine and Molecular Imaging. - 1619-7070. ; 13:9, s. 456-461
Journal article (peer-reviewed) abstract
In order to investigate the kinetics of the passage from the brain parenchyma to the lymphatic system in vivo a high resolution scintillation camera technique was developed. Albumin, albumin colloids and dextran labelled with 99mTc were injected into the right side of the thalamus of anesthetized rats. Continuous measurement of the activity distribution in head and neck were performed for 70 min. Rate constants were calculated by means of a computer program for compartment analysis. The animals were killed 10 h postinjection, to measure the activity in tissue samples. For some animals, images were registered up to 24 h after injection. This work presents an in vivo technique to clarify the particle flow paths in the brain and make quantification possible. The method is simple and does not require continuous blood or lymph sampling. Our work shows that there is a substantial flow of injected material from the brain via lamina cribriformis to the lymphatic system. This route is of great interest for the drainage of the interstitial fluid of the brain. We have also shown a difference in flow for dextran particles with different charge
