PubMed · 6196797
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
B Pernow. 1983. Substance P.. https://pubmed.ncbi.nlm.nih.gov/6196797/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Opioid analgesia, the selective suppression of pain without effects on other sensations, also distinguishes between different types of pain: severe, persistent pain is potently inhibited by opioids, but they fail to cohceal the sensation of a pinprick. The cellular basis for this specificity was analyzed by means of patch-clamp experiments performed on fluorescently labeled nociceptive neurons (nociceptors) that innervate rat tooth pulp. Activation of the mu opioid receptor inhibited calcium channels on almost all small nociceptors but had minimal effect on large nociceptors. Somatostatin had the opposite specificity, preferentially inhibiting calcium channels on the large cells. Because persistent pain is mediated by slow-conducting, small nociceptors, opioids are thus likely to inhibit neurotransmitter release only at those primary synapses specialized for persistent pain.
We previously found that the contractile motility of the jejunum was increased 4 weeks after transplantation, and that the dominant intrinsic neural component was changed from cholinergic to nonadrenergic, noncholinergic (NANC). The present study investigated the long-term effects of transplantation on jejunal motility using rats that survived for 2 years after surgery. Jejunal strips were harvested from various groups of rats, and intestinal motility was assessed by electrical transmural stimulation. Stimulation produced a similar increase of contraction at 4 weeks and 2 years after grafting. Pretreatment with atropine showed that the cholinergic component of contraction was 45%, 24%, 32%, and 24% in controls, rats 4 weeks after transplantation, 2-year-old controls, and rats 2 years after transplantation, respectively. The NANC component (obtained with atropine and guanethidine) in each group was, respectively, 56%, 73%, 60%, and 69%. The actual value of the tetrodotoxin-insensitive myogenic component was significantly increased at 2 years after transplantation. A substance P antagonist ([Arg6, D-Trp7,9, Mephe8], substance P 6-11), inhibited most of the NANC contraction after transplantation. These results suggested that substance P has a key role in the motility of transplanted small bowel throughout the life of the grafts.
Pathophysiology and principles for diagnosis of migraine, in particular ways to obtain an accurate history between attacks, are presented in the introduction. Identification of migraine triggers is an extremely important part of migraine therapy. Selected pain-relieving drugs should include primarily simple analgesics and antiemetics, while sumatriptan should be reserved mainly for severe migraine attacks. Pharmacotherapy, psychological and physical therapy are all components of a systemic approach to the treatment of migraine. To discontinue overused medication is the first step in the prevention of migraine. A number of available drugs are able to reduce the frequency and severity of migraine attacks. Several considerations should be evaluated before symptomatic and prophylactic therapies are introduced. Our strategies are based on experience collected during the treatment of 82 patients.