scholarly journals Mediation systems in bacterial lipopolysaccharide-induced hypotension and disseminated intravascular coagulation. I. The role of complement.

1975 ◽  
Vol 142 (6) ◽  
pp. 1570-1590 ◽  
Author(s):  
R J Ulevitch ◽  
C G Cochrane ◽  
P M Henson ◽  
D C Morrison ◽  
W F Doe

We have studied the role of complement in lipopolysaccharide (LPS)-induced hypotension and disseminated intravascular coagulation (DIC) by comparing the effects of injection of three preparations of LPS from E. Coli 0111:B4, S. minnesota Re595, and S. marcescens. Injections of nonlethal doses of these LPS preparations into normal rabbits produced decreases in mean arterial blood pressure during a 5-h period. When rabbits treated with cobra venom factor (CoF) to deplete C3 were injected with the various LPS preparations, mean arterial pressures fell at a rate and extent essentially identical to that observed in normal rabbits. Rabbits genetically deficient in C6 also demonstrated LPS-induced hypotensive changes. Only minimal, or no changes in plasma C3 levels or serum CH50 values were detected in normal rabbits after LPS injection. Hypotensive changes were also induced in rabbits when complement was rapidly activated by intravenous injection of CoF. In contrast to the hypotension induced by LPS, the fall in arterial pressure associated with the consumption of complement was short lived and required the rapid consumption of considerable amounts of C3. The occurrence of DIC noted in normal rabbits injected with each preparation of LPS was not inhibited in either rabbits treated with cobra factor or in C6-deficient rabbits. The DIC was most pronounced after injection of Re595 and S. marcescens LPS. Injection of the various LPS preparations produced a rapid disappearance of circulating neutrophils and mononuclear cells, which occurred with the same kinetics and to the same extent in normal, CoF-treated, and C6-deficient rabbits. Injection of either Re595 LPS or S. marcescens LPS produced a biphasic disappearance of circulating 51Cr-platelets. In contrast, injection of 0111:B4 LPS affected only slightly the rate of disappearance of 51Cr-platelets. Depletion of C3 by cobra factor treatment had no effect on the disappearance of platelets in animals injected with 0111:B4. In marked contrast cobra factor treatment greatly reduced the initial rapid disappearance of platelets in rabbits injected with either Re595 or S. marcescens LPS, but had no effect in the secondary disappearance phase.

1976 ◽  
Vol 04 (04) ◽  
pp. 383-389 ◽  
Author(s):  
Samuel H. H. Chan ◽  
Anthony Koo ◽  
K. M. Li

In pentobarbital anesthezied rats, the medial portion of the medullary reticular formulation has been identified to be directly involved in the hypotensive effect of extracts from the seeds of Cassia tora. This conclusion was drawn from the observed decrease in arterial blood pressure following local injection of extracts of this herb into this reticular site and from its inability to promote hypotension when the same reticular site has been electrolytically lesioned. The role of the medullary reticular formation in the Cassia tora-induced hypotension was suggested to be one which modulates the basic cardiovascular reflexes, favoring a decrease in vasomotor tone.


Author(s):  
A. Kulikov

Presented material reveals main links in the pathogenesis of hemostatic disorder. In particular, attention is paid to the role of the lungs, liver and other organs in the development of this process. Role of vascular wall and blood cells in regulation of the physical state of blood is described in detail. The most frequent factors leading to hypercoagulation are indicated. Difference between hypercoagulation and thrombophilia is shown. The latter is found in clinical practice quite often, but at the same time, it is poorly diagnosed. Such a terrible complication of hemostatic disorder as disseminated intravascular coagulation is described. Its classification, stages of development, clinical manifestations are offered to the readers.


2020 ◽  
Vol 129 (6) ◽  
pp. 1310-1323
Author(s):  
Jennifer L. Magnusson ◽  
Craig A. Emter ◽  
Kevin J. Cummings

The role of serotonin in arterial blood pressure (ABP) regulation across states of vigilance is unknown. We hypothesized that adult rats devoid of CNS serotonin (TPH2−/−) have low ABP in wakefulness and NREM sleep, when serotonin neurons are active. However, TPH2−/− rats experience higher ABP than TPH2+/+ rats in wakefulness and REM only, a phenotype present only in older males and not females. CNS serotonin may be critical for preventing high ABP in males with aging.


1984 ◽  
Vol 4 (1) ◽  
pp. 107-109 ◽  
Author(s):  
E. Shohami ◽  
A. Sidi

The effect of haemorrhagic hypotension on the levels of prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and 6-keto prostaglandin F1α (6-keto-PGF1α) in cortical tissue of rats was studied. Lightly anesthetized rats were subjected to steady-state hypotension for 15 min, with a mean arterial blood pressure of 80, 60, and 40 mm Hg, and compared to a control group of normotensive rats. No significant change was found in the levels of PGE2 and TXB2. The level of 6-keto-PGF1α increased from 7.8 ± 0.9 to 14.1 ± 1.9 pg/mg protein (p < 0.02) at 80 mm Hg. Our findings suggest that prostacyclin, which is a potent vasodilator, might play a role in setting the lower limit of the autoregulation range.


1994 ◽  
Vol 1 ◽  
pp. 210
Author(s):  
K. Okajima ◽  
M. Uchida ◽  
K. Murakami ◽  
H. Okabe ◽  
K. Takatsuki

2009 ◽  
Vol 81 (3) ◽  
pp. 589-603 ◽  
Author(s):  
Sergio L. Cravo ◽  
Ruy R. Campos ◽  
Eduardo Colombari ◽  
Mônica A. Sato ◽  
Cássia M. Bergamaschi ◽  
...  

Several forms of experimental evidence gathered in the last 37 years have unequivocally established that the medulla oblongata harbors the main neural circuits responsible for generating the vasomotor tone and regulating arterial blood pressure. Our current understanding of this circuitry derives mainly from the studies of Pedro Guertzenstein, a former student who became Professor of Physiology at UNIFESP later, and his colleagues. In this review, we have summarized the main findings as well as our collaboration to a further understanding of the ventrolateral medulla and the control of arterial blood pressure under normal and pathological conditions.


2001 ◽  
Vol 280 (5) ◽  
pp. R1261-R1268 ◽  
Author(s):  
Takashi Miyawaki ◽  
Ann K. Goodchild ◽  
Paul M. Pilowsky

The role of the 5-hydroxytryptamine (5-HT1A) receptors in the rostral ventrolateral medulla (RVLM) on somatosympathetic, baroreceptor, and chemoreceptor reflexes was examined in anesthetized rats. Microinjection of the selective 5-HT1A agonist 8-hydroxy-di- n-propylamino tetralin (8-OH-DPAT) decreased arterial blood pressure and splanchnic sympathetic nerve activity (SNA). Electrical stimulation of the hindlimb evoked early and late excitatory sympathetic responses. Bilateral microinjection in the RVLM of 8-OH-DPAT markedly attenuated both the early and late responses. This potent inhibition of the somatosympathetic reflex persisted even after SNA and arterial blood pressure returned to preinjection levels. Preinjection of the selective 5-HT1A antagonist NAN-190 in the RVLM blocked the sympathoinhibitory effect of 8-OH-DPAT and attenuated the inhibitory effect on the somatosympathetic reflex. 8-OH-DPAT injected in the RVLM did not affect baroreceptor or chemoreceptor reflexes. Our findings suggest that activation of 5-HT1A receptors in the RVLM exerts a potent, selective inhibition on the somatosympathetic reflex.


1992 ◽  
Vol 41 (2) ◽  
pp. 71-75 ◽  
Author(s):  
H. Asakura ◽  
H. Jokaji ◽  
M. Saito C. Uotani ◽  
I. Kumabashiri ◽  
E. Morishita ◽  
...  

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