PubMed · 13991801
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
G SCHLAG. 1963. [Technic and problems in general anesthesia].. https://pubmed.ncbi.nlm.nih.gov/13991801/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Positron emission tomography (PET) measurements in 6-month-old F344/N rats were performed in the conscious state and the influence of chloral hydrate, ketamine, and pentobarbital anesthesia on dopamine D(1) (DA-D(1)) receptor binding was evaluated using [(11)C]SCH23390, a selective DA-D(1) receptor ligand. To perform the PET study in conscious rats, an original fixation apparatus was developed and the animals were trained to acclimate to the scanning atmosphere for 3 h. This training was carried out twice a day for 2 weeks. PET measurements in conscious rats were successful, since the trained rats scarcely moved during the scanning (as monitored by video camera) and since highly reproducible measurements of binding potential (BP) were derived from their scanning. Chloral hydrate and ketamine anesthesia significantly increased the striatal BP of DA-D(1) receptors by 36% and 46%, respectively, compared to that observed in the conscious state. In contrast, pentobarbital markedly decreased the BP by 41%. These BP values of DA-D(1) receptors were calculated using a curve-fitting method. Our results indicate that PET studies in rats should be performed in the conscious state since the anesthetics dramatically modified ligand-receptor bindings, such as DA-D(1) receptor binding, in rat brain.
Neuropathic pain arising from peripheral nerve injury is a clinical disorder characterized by a combination of spontaneous pain, hyperalgesia and tactile pain (allodynia), and remains a significant clinical problem since it is often poorly relieved by conventional analgesics. To seek an analgesic compound(s) in Chinese herbs, we examined the effect of seven Chinese herbs that are routinely prescribed for pain management in two neuropathic pain models: allodynia induced by intrathecal administration of prostaglandin F2alpha (PGF2alpha) and by selective L5 spinal nerve transection. The extracts of Moutan cortex and Coicis semen dose-dependently alleviated the PGF2alpha-induced allodynia by oral administration 1 h before intrathecal injection of PGF2alpha. When orally administrated every day for 7 days, these extracts attenuated neuropathic pain in the ipsilateral side, but not in the contralateral side, day 7 after L5 spinal nerve transection. The increase in NADPH diaphorase activity in the spinal cord associated with neuropathic pain was also blocked by these extracts. These results suggest that Moutan cortex and Coicis semen contain substances effective in neuropathic pain.
Vascular capacitance is reduced by endothelin-1 (ET-1) in deoxycorticosterone (DOCA)-salt hypertensive rats. This may contribute to hypertension development. Because the splanchnic blood vessels (especially veins) are important in determining vascular capacitance, we tested the hypothesis that ET-1 levels in the splanchnic vasculature are elevated in hypertensive DOCA-salt compared with normotensive rats. Tissue ET-1 content was measured by ELISA in aorta, vena cava, superior mesenteric artery and vein, and small mesenteric arteries and veins from normotensive sham-operated (sham) and 4-wk DOCA-salt rats. We also determined ET-1 concentration in aortic and portal venous blood (draining the nonhepatic splanchnic organs) in anesthetized and conscious sham and DOCA-salt rats before and after acute blockade of ETB receptor-mediated plasma clearance of ET-1. Results showed a higher ET-1 content in veins than in arteries of similar size. However, ET-1 content was similar in vessels from sham and DOCA-salt rats, except in aorta and superior mesenteric artery, where ET-1 content was greater in DOCA-salt rats. ET-1 concentration was significantly higher in portal venous than in aortic blood, indicating net nonhepatic splanchnic release (nNHSR) of ET-1. However, nNHSR of ET-1 was similar in sham and DOCA-salt rats. Although nNHSR of ET-1 increased significantly after ETB receptor blockade in sham rats, it was completely unchanged in DOCA-salt rats. These data suggest that, despite the absence of ETB receptor-mediated plasma clearance of ET-1, neither the venous peptide content nor the net release of ET-1 is increased in the splanchnic vasculature of DOCA-salt rats. These results argue against the hypothesis that increased venomotor tone in DOCA-salt hypertension is caused by increased ET-1 concentration around splanchnic venous smooth muscle cells.