Vascular 5-HT1-like receptors mediating vasoconstriction and vasodilatation: their characterization and distribution in the intact canine cardiovascular system

1. In anaesthetized dogs, intra-left atrial administration of 5-hydroxytryptamine (5-HT) and selected tryptamine analogues (5-carboxamidotryptamine, 5-CT; 5-methyl tryptamine, 5-MT; alpha-methyl 5-hydroxytryptamine, alpha-HT; sumatriptan, Sum) in the presence of ketanserin and MDL72222 (5-HT2 and 5-HT3 receptor antagonists, respectively), produced dose-related changes in carotid, coronary and renal vascular conductance mediated by vascular 5-HT1-like receptors. 2. In the carotid vascular bed, 5-HT, 5-MT, alpha-HT and Sum were vasoconstrictors with a rank order of potency (comparing ED50 values) of 5-HT = Sum > 5-MT > alpha-HT. By contrast in this vascular bed, 5-CT was a potent vasodilator. 3. In the coronary vascular bed, 5-HT, 5-CT, 5-MT and alpha-HT were vasodilators with a rank order of potency (comparing ED50 values) of 5-CT > 5-HT > 5-MT > alpha-HT. In this vascular bed, Sum was without effect. 4. In the renal vascular bed, 5-HT, 5-CT, 5-MT, alpha-HT and Sum were vasoconstrictors with a rank order of potency (comparing ED50 values) of 5-CT > 5-HT > Sum > 5-MT > alpha-HT. 5. The coronary (and carotid) vasodilator responses to 5-CT were antagonized by the 5-HT1-like receptor antagonists, spiperone (1 mg kg-1) and methiothepin (0.1 mg kg-1), whereas the renal vasoconstrictor responses to this tryptamine analogue were antagonized only by methiothepin. 6. It is concluded from these studies that agonist finger-printing in vivo, using tryptamine analogues,identifies and confirms the functional presence of at least two pharmacologically distinct subtypes of the 5-HT1-like receptor in the intact canine cardiovascular system. These two subtypes are located on the vascular smooth muscle and mediate direct vasoconstriction and vasodilatation responses in vivo.7. In addition, these studies confirm that the distribution of these subtypes within the major vascular beds, shows a marked heterogeneity. The carotid vascular responses to the tryptamine analogue sindicate the presence of both the vasodilator and the vasoconstrictor subtypes. The coronary vascular responses to these analogues are, however, consistent with presence of the vasodilator subtype, only. By contrast, the renal vascular responses to these analogues indicates only the presence of the vasoconstrictor subtype.     

Percutaneous management of benign renal cysts

Percutaneous emptying of benign renal cysts represents the adopted treatment for this kind of pathology. The introduction of pure ethilic alcohol (95 degrees) is usually associated with emptying because it determines the necrosis of the secreting epithelious with recurrences and little significant complications. This treatment is the less bloody solution that can be executed in surgery and for this reason it is proposed in the time as an alternative to surgery treatment of removal.     

Cross-sectional assessment of ELISA reactivity in leprosy patients, contacts, and normal population using the semisynthetic antigen natural disaccharide octyl bovine serum albumin (ND-O-BSA) in Cebu, The Philippines

An indirect enzyme-linked immunosorbent assay (ELISA) using natural disaccharide octyl bovine serum albumin (ND-O-BSA) as antigen was used in testing leprosy patients, contacts and a normal population in Cebu, The Philippines, from 1985 to 1989. A total of 1413 persons were studied. The results suggested that ELISA reactivity and the bacterial index (BI) correlate in a general way. In multibacillary (MB) leprosy, positivity ranges from 54.2% to 92.3% among patients with a BI of < 2+ to > 4+ on the Ridley scale, with an overall average of 84.5%. Paucibacillary (PB) leprosy patients have a low degree of reactivity, with only 15.0% ELISA positive. The test is more efficient in detecting MB than PB leprosy. The contacts of MB leprosy showed 6.5% positivity; contacts of PB leprosy, 7.0% positivity. The normal population showed 1.7% positive ELISA or 17 per thousand population, which is very much less than that of the household contacts. However, because the normal population is a much larger population than the household contact population in a community, more new leprosy cases would emanate from it. Leprosy workers are concerned about the transmission of the disease to household contacts. However, for the reason stated above, we should be more concerned with the silent spread of the disease to the normal population in the community.(ABSTRACT TRUNCATED AT 250 WORDS)     

Optimal electrical stimulation for latissimus dorsi muscle after cardiomyoplasty

A new property of the presequence of the mitochondrial precursor protein cytochrome oxidase subunit IV is presented. This mitochondrial presequence induces interbilayer contacts between large unilamellar vesicles consisting of phosphatidylcholine and cardiolipin. The presequence-vesicle aggregates can be dissociated by applying a membrane potential across the bilayers (negative inside). These effects require the presence of cardiolipin and are not observed for other negatively charged phospholipids. We propose a role for the presequence in the formation and dissociation of mitochondrial contact sites.     

Digitalis-like and vasoconstrictor effects of endogenous digoxin-like factor(s) from the venom of Bufo marinus toad

Digitalis glycoside-like properties of the Bufo marinus toad crude venom and one of its constituents, bufalin, were studied in various assay systems. In concentrations 0.3-30 micrograms/ml crude venom increased the contractility of isolated electrically driven rat atria, constricted rat aortic rings, inhibited ouabain-sensitive Na+,K(+)-ATPase in rat erythrocytes and the Na+,K(+)-pump in rat aorta, and cross-reacted with antidigoxin antibody from the dissociation enhanced lanthanide fluoroimmunoassay (DELFIA). These effects were unaffected by adrenoceptor blockers and the 5-HT antagonist, deseril, but were blocked by antidigoxin antibody. Bufalin (10-30 microM) increased myocardial contractility and inhibited Na+,K(+)-ATPase in rat erythrocytes similarly to crude Bufo marinus venom. In rat aorta bufalin showed weak and delayed vasoconstrictor activity which was antagonized by 2 microM phentolamine, and had a biphasic effect on the Na+,K(+)-pump; 0.5-1.0 microM bufalin stimulated the pump, while higher concentrations inhibited its activity. Although the effects of bufalin were blocked by antidigoxin antibody, bufalin showed very low digoxin-like immunoreactivity in the DELFIA. These observations suggest that, in addition to bufalin, Bufo marinus venom contains at least one more digitalis-like steroid with significant intrinsic vasoconstrictor activity which, unlike bufalin, constricts the blood vessels acting directly via inhibition of the sodium pump in the vascular smooth muscle membrane.     

Neurohormonal control of gallbladder motility by intra-ileal and intracolonic nutrients--a review

The duodenum controls gallbladder motility mainly via stimulatory mechanisms, whereas intraileal and intracolonic nutrients have mainly inhibitory effects on postprandial as well as interdigestive gallbladder motility, which are described in particular. Possible mechanisms for the neurohormonal mediation of the effects of intraileal and intracolonic nutrients on gallbladder motility as well as the possible physiological importance of these effects are discussed.     

Use of [6,6-2H2]glucose and of low-enrichment [U-13C6]-glucose for sequential or simultaneous measurements of glucose turnover by gas chromatography-mass spectrometry

We developed gas chromatography-mass spectrometric methods for assaying the enrichment of 99 at.% [6,6-2H2]glucose and 30 at.% [U-13C6]glucose, although both tracers are mostly M + 2. 13C enrichment is determined either by the C-1 to C-5 fragment of glucose aldonitrile pentaacetate or by oxidation of glucose to glucarate. 2H enrichment is assayed as the difference between the 13C enrichment of glucarate and the 2H + 13C enrichment of glucose. The techniques, which were validated in in vivo experiments, are applicable to the determination of simultaneous or sequential measurements of the rate of glucose appearance before and after an intervention. They could also be applied to the simultaneous determination of (i) gluconeogenesis by incorporation of a 13C-labeled precursor into glucose and (ii) the rate of glucose appearance by [6,6-2H2]glucose infusion.     

Contribution to modelling of process planning

The process planning activities have been performed up to now manually and based on personal experience of those who are engaged. Development in computer based planning attempts to make the planning process to be carried out easier for the staff and to make use of experiences gained in the past with help of expert systems. The two principles used are the variant and the generic approach.