126
|
Abstract
A new non-benzodiazepine compound proposed as a non-sedating anxiolytic was tested in the mouse exploratory model of anxiety. CGS 9896 significantly increased the number of light dark transitions at doses beginning at 7.5 mg/kg i.p. Analysis of general locomotor activity at these doses revealed no change in spontaneous motor activity in a photocell equipped activity monitor. Pretreatment with the benzodiazepine receptor antagonist, Ro15-1788, 10 mg/kg i.p., blocked the increase in light dark transitions produced by CGS 9896. These data support the interpretation that CGS 9896 acts as an anxiolytic through the benzodiazepine receptor, and appears to have no sedating properties within the anxiolytic dose range.
Collapse
|
127
|
Lessor RA, Bajwa BS, Rice KC, Jacobson AE, Streaty RA, Klee WA, Smith CB, Aceto MD, May EL, Harris LS. Probes for narcotic receptor mediated phenomena. 13. Potential irreversible narcotic antagonist-based ligands derived from 6,14-endo-ethenotetrahydronororipavine with 7-(methoxyfumaroyl)amino, (bromoacetyl)amino, or isothiocyanate electrophiles: chemistry, biochemistry, and pharmacology. J Med Chem 1986; 29:2136-41. [PMID: 3023609 DOI: 10.1021/jm00161a002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
N-Allyl-, N-(cyclopropylmethyl)-, and N-propyl-endo-ethenotetrahydronororipavines (N-substituted 6,14-endo-etheno-4,5-epoxy-3-hydroxy-6-methoxymorphinans) were synthesized with potential acylating or alkylating moieties at the C-7 position (isothiocyanato, (bromoacetyl)amino, and (methoxyfumaroyl)amino) and examined in vivo for their narcotic agonist and antagonist activities and for their ability to interact with opioid receptors in vitro. The N-(cyclopropylmethyl)-substituted compounds were found to have the highest affinity for opioid receptors among these N-substituted compounds, although all of them were found to be reasonably potent narcotic antagonists in the mouse tail flick vs. morphine assay. Their in vivo potency ranged from 1/8 to 4 times that of nalorphine on intravenous injection in mice. Rat brain membrane binding studies indicated that the compounds interacted with opioid receptors with potencies that ranged from 0.5 times that of morphine (8c, 9c, and 10c) to 0.017 that of morphine (8b). Among the compounds studied here, only the previously reported isothiocyanato compound (10c) and (methoxyfumaroyl)amino compound (8c) interacted irreversibly and selectively with mu or delta opioid receptors, respectively, in assays using NG108-15 neuroblastoma-glioma hybrid cells and/or in a rat brain membrane preparation. Both 8c and 10c were found to interact irreversibly, to a limited extent, with kappa opioid sites in rat brain membranes in which the mu and delta opioid receptors were depleted by interaction with the mu-selective irreversible ligand BIT and the delta-selective irreversible ligand FIT. Neither compound showed irreversible actions in the electrically stimulated mouse vas deferens preparation.
Collapse
|
128
|
Abrahm DR, Hollingsworth PJ, Smith CB, Jim L, Zucker LB, Sobotka PA, Vinik AI. Decreased alpha 2-adrenergic receptors on platelet membranes from diabetic patients with autonomic neuropathy and orthostatic hypotension. J Clin Endocrinol Metab 1986; 63:906-12. [PMID: 3018030 DOI: 10.1210/jcem-63-4-906] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Platelet adrenergic receptors were studied in normal subjects and diabetic patients with autonomic neuropathy to determine the relationship between adrenoreceptor status and orthostatic hypotension. The binding of [3H]clonidine and [3H]yohimbine to platelet membranes was measured in diabetic patients with autonomic neuropathy and orthostatic hypotension (n = 12) and without orthostatic hypotension (n = 11), diabetic patients without autonomic neuropathy (n = 12), and normal subjects (n = 9). Mean basal and standing plasma norepinephrine levels were not different in the four groups, and there was no relationship between orthostasis and norepinephrine responses. The diabetic patients with orthostatic hypotension had a significantly greater fall in mean blood pressure [31 +/- 2.8 (+/- SE) mm Hg] than any of the other three groups. Diabetic patients with diabetic autonomic neuropathy and orthostatic hypotension had a 30-40% decrease in number of platelet alpha 2-adrenergic receptors, as demonstrated by [3H]clonidine and [3H]yohimbine binding. The maximum number of binding sites for clonidine was 34 +/- 2.8 (+/- SE) fmol/mg protein in normal subjects, 27.4 +/- 3.4 in diabetic patients with neuropathy, 26 +/- 2.5 in diabetic patients with autonomic neuropathy without orthostatic hypotension, and 20.4 +/- 3.8 fmol/mg protein in diabetic patients with autonomic neuropathy with orthostatic hypotension (P less than 0.001). The maximum number of binding sites for yohimbine was 112 +/- 12.6 in normal subjects, 127 +/- 10 in diabetic patients without orthostatic hypotension, and 87 +/- 12.4 fmol/mg protein in patients with diabetic autonomic neuropathy with orthostatic hypotension (P less than 0.001). Reduced platelet alpha 2-receptors are associated with postural hypotension in diabetic autonomic neuropathy. If applicable to the postjunctional alpha 2-adrenergic receptor on sympathetic neurons, reduced vascular responses to changes in posture would be expected despite normal or enhanced norepinephrine secretion.
Collapse
|
129
|
Smith CB, Griffiths MM, Wei LS. Rat cytomegalovirus infection enhances type II collagen arthritis in rats. ARTHRITIS AND RHEUMATISM 1986; 29:1263-8. [PMID: 3021178 DOI: 10.1002/art.1780291012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of rat cytomegalovirus (RCMV) infection on type II collagen-induced arthritis was studied in DA rats. Rats were infected with RCMV 5 days before, simultaneously with, or 5 days after immunization with calf type II collagen. Control rats were either given type II collagen alone or were injected with normal rat salivary gland (NRSG) simultaneously with collagen immunization. Severity of arthritis in each limb was graded on a scale of 1-4 (maximum score 16). In 5 experiments, peak arthritis scores in the RCMV groups were twice those of the control groups which received NRSG or collagen only (8-9 versus 4-6). Radiographs of involved joints showed greater destruction of cartilage and articular bone in the RCMV rats than in the NRSG control group. Repeated attempts to culture RCMV from joint tissues were unsuccessful. Our results indicate that RCMV infection enhances the arthritic process in this experimental model of an autoimmune arthritis.
Collapse
|
130
|
Kirlin PC, Das S, Grekin R, Juni J, Weiss RJ, Smith CB, Gross M, Pitt B. Sympathetic inhibition with methyldopa in heart failure. J Cardiovasc Pharmacol 1986; 8:1092-100. [PMID: 2429085 DOI: 10.1097/00005344-198609000-00031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hypothesis that withdrawal of increased sympathetic activity may be beneficial in heart failure was tested by administration of the centrally acting adrenergic inhibitor methyldopa. Fourteen subjects with chronic, stable New York Heart Association Functional Class 2 or 3 heart failure receiving digitalis and diuretics were randomized to methyldopa (n = 8) 500-1000 mg daily or placebo (n = 6). Clinical, hemodynamic, neurohumoral, and platelet alpha 2-receptor effects were studied after chronic (3 weeks) administration. Sympathetic inhibition did not alter symptom status or exercise duration but reduced plasma norepinephrine concentration during exercise and permitted the same level of exercise to be attained at a lower pressure-rate product, indicating reduced myocardial oxygen consumption. Left ventricular ejection fraction and stroke volume tended to increase, and systemic vascular resistance tended to decrease during exercise after methyldopa administration, suggesting enhanced vasodilation. Upright plasma renin activity increased from 8.2 +/- 2.2 to 13.3 +/- 3.0 ng/nl/h (p = 0.03) after methyldopa, but plasma antidiuretic hormone concentration changed insignificantly. In a subset of patients, platelet alpha 2-receptor density and affinity were unaltered. Renal function was also unchanged. Thus, sympathetic inhibition induced by methyldopa in selected patients with chronic, stable heart failure does not worsen symptom status or exercise performance, and may produce a beneficial effect by withdrawal of excess sympathetic activity with reduction of plasma norepinephrine levels.
Collapse
|
131
|
Simpson PJ, Smith CB, Rosenthal G, Lucchesi BR. Reduction in the incidence of thrombosis by the thromboxane synthetase inhibitor CGS 13080 in a canine model of coronary artery injury. J Pharmacol Exp Ther 1986; 238:497-501. [PMID: 3735129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The antithrombotic potential of the thromboxane (TX) synthetase inhibitor CGS 13080 (CGS) was studied in an anesthetized open-chest canine model of coronary artery intimal wall injury induced by the local application of a low amperage electrical current (100 microA for 6 hr). CGS was administered by i.v. infusion (1 mg/kg/min) beginning 30 min before applying the direct current to the intimal wall of the vessel. CGS did not alter basal values for heart rate, blood pressure or coronary blood flow. After 6 hr of current application to the vessel, 1 of 10 CGS-treated dogs exhibited complete thrombotic occlusion of the circumflex coronary artery compared to 8 of 10 nontreated control dogs (P less than .01). Thrombus masses within the injured left circumflex coronary artery were: Control, 25.9 +/- 4.5 mg (n = 10) and CGS, 11.0 +/- 2.8 mg (n = 10); P less than .01. The concentration of TXB2 determined ex vivo in serum from thrombin-activated whole blood was decreased by CGS administration: Control, 43.15 +/- 16.08 ng/ml (n = 9) vs. CGS, 1.72 +/- .69 ng/ml (n = 10); P less than .001. Ex vivo platelet aggregometry demonstrated that arachidonic acid (0.65 mM)-induced aggregation was reduced from a control value of 82.3 +/- 7.8% (n = 10) to 45.0 +/- 11.3% (n = 10) (P less than .05), whereas aggregation in response to ADP (5 micrograms/ml) or collagen (156 and 312 micrograms/ml) was unaffected. CGS was compared with two other TX synthetase inhibitors, U63557A and OKY1581, for the ability to divert cyclic endoperoxide metabolism to the synthesis of prostaglandin (PG) E2 and prostacyclin in response to stimulation of whole blood in vitro with collagen (25 micrograms/ml). CGS, U63557A and OKY 1581 were found to be equally effective with respect to PGE2 and 6-keto PGF1 alpha production in vitro. The data demonstrate that CGS is an effective antithrombotic agent in vivo and that it selectively inhibits arachidonic acid-induced platelet aggregation ex vivo and the formation of TXA2 in thrombin-activated whole blood.
Collapse
|
132
|
|
133
|
Smith CB, Wei LS, Griffiths M. Mouse cytomegalovirus is infectious for rats and alters lymphocyte subsets and spleen cell proliferation. Arch Virol 1986; 90:313-23. [PMID: 3015085 PMCID: PMC7086953 DOI: 10.1007/bf01317379] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The Smith strain of mouse cytomegalovirus (MCMV) was infectious for infant and mature DA strain laboratory rats as judged by development of neutralizing antibodies and specific spleen cell proliferation on stimulation with MCMV antigen. An i.p. inoculum of 10(6) PFU of MCMV was fatal for more than two-thirds of infant mice (1-7 days of age), and disseminated viral infection was documented by isolation of virus from body organs. In contrast, weanling and adult rats did not become ill as a result of infection with a larger inoculum of 10(7) PFU. However, these older MCMV infected rats did show transient reversals of T helper/suppressor cell ratios and alterations of immune cell function as detected by in vitro spleen cell proliferation assays. Seven days after MCMV infection, there was a generalized increase in 3H-thymidine incorporation by spleen cells in both resting (unstimulated) cultures and cultures exposed to mitogens (Con A, PHA, LPS) and to MCMV antigen. At 14 days, the spleen cell proliferation in the unstimulated cultures returned to normal but was depressed compared to controls in response to Con A. These observations show that laboratory rats are susceptible to MCMV infection and that asymptomatic infection may occur and cause transient alterations in lymphocyte subsets and in their reactivity to mitogens.
Collapse
|
134
|
Silverstein F, Smith CB, Johnston MV. Effect of clonidine on platelet alpha 2-adrenoreceptors and plasma norepinephrine of children with Tourette syndrome. Dev Med Child Neurol 1985; 27:793-9. [PMID: 3005096 DOI: 10.1111/j.1469-8749.1985.tb03804.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Clonidine, an alpha 2-adrenoreceptor agonist, is useful for treating some patients with Tourette syndrome, and it has been suggested that their noradrenergic receptors are 'subsensitive'. The authors measured plasma norepinephrine and specific binding of 3H-clonidine and 3H-yohimbine, an alpha 2-adrenoreceptor antagonist, to receptors on platelet membranes from children with Tourette syndrome. Before clonidine treatment, plasma norepinephrine, the maximum number of binding sites and the dissociation constants for both ligands were the same as for the controls. After two weeks of treatment there was little clinical improvement, but the number of binding sites for 3H-yohimbine decreased and plasma norepinephrine also decreased in four of the five patients. Over the next six months all five patients continued to improve clinically, but both indices of noradrenergic activity returned towards baseline values. The data suggest that clonidine's action may be independent of its prominent effects on alpha 2-adrenergic receptors and norepinephrine release.
Collapse
|
135
|
Aceto MD, Harris LS, Woods JH, Katz JL, Smith CB, Medzihradsky F, Jacobson AE, Shiotani S. Pharmacological actions of the racemic and the enantiomeric 1,4-dimethyl-10-hydroxy-2,3,4,5,6,7-hexahydro-1,6-methano-1H-4-benz azo nines (C-homobenzomorphans). JAPANESE JOURNAL OF PHARMACOLOGY 1985; 39:7-19. [PMID: 4068392 DOI: 10.1254/jjp.39.7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The racemate and optical isomers of the C-homobenzomorphans, 1,4-dimethyl-10-hydroxy-2,3,4,5,6,7-hexahydro-1,6-methano-1H-4-benzaz onine, were evaluated in a number of assays sensitive to narcotics of different types. All three C-homobenzomorphans were active in vitro in guinea pig ileum, mouse vas deferens, and rat brain membrane binding assays, but were of low potency. These C-homobenzomorphans showed different profiles of in vivo activity. The (+)-isomer and racemate were active as agonists in the tail-flick assay, whereas the (-)-isomer was inactive. At higher doses, the (-)-isomer and the racemate behaved as antagonists of morphine in the tail-flick assay. All three compounds were active in the phenylquinone test, but naloxone did not block this effect. In addition, all three were potent in the hot-plate test. Neither of the isomers substituted for morphine in dependent rats or monkeys. However, the (+)-isomer precipitated withdrawal in these monkeys. The (-)-isomer produced opioid-like physical dependence in both rats and monkeys. Some of the implications regarding the results with these remarkable homobenzomorphans are discussed.
Collapse
|
136
|
Smith CB. Article does not show harm from midforceps. Am J Obstet Gynecol 1985; 152:604-5. [PMID: 4014360 DOI: 10.1016/0002-9378(85)90641-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
137
|
Ingvar MC, Maeder P, Sokoloff L, Smith CB. Effects of ageing on local rates of cerebral protein synthesis in Sprague-Dawley rats. Brain 1985; 108 ( Pt 1):155-70. [PMID: 3978396 DOI: 10.1093/brain/108.1.155] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The effects of ageing on local rates of protein synthesis in 39 brain structures in resting conscious rats have been examined. Young adult rats (aged 6 months) have been compared with a group of middle-aged/aged rats (aged 15-23 months). The results show that ageing is associated with significant decreases in rates of protein synthesis in the brain as a whole as well as in several specific brain regions. Brain regions involved in visual and auditory function were selectively affected, perhaps due to a chronic lack of sensory input. Several regions involved in motor function and two areas in the limbic system had significantly decreased rates of protein synthesis in the old rats. Notably, there was a significant age-related decrease in protein synthesis in the locus coeruleus which contains the cell bodies of origin of the major ascending noradrenergic innervation of the cortex.
Collapse
|
138
|
Smith CB. Ultrasound without history. Am J Obstet Gynecol 1985; 151:421-2. [PMID: 3881969 DOI: 10.1016/0002-9378(85)90325-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
139
|
Smith CB. Diagnostic ultrasound. Am Fam Physician 1985; 31:22, 24, 32. [PMID: 3883725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
140
|
Moises HC, Smith CB. Changes occur in central adrenoreceptor function following long-term morphine treatment and during morphine withdrawal. Neuropeptides 1984; 5:29-32. [PMID: 6152326 DOI: 10.1016/0143-4179(84)90019-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Radioligand binding techniques were used in combination with in vivo electrophysiological recording to characterize changes in beta adrenoreceptor activity in various brain areas in rats treated chronically with morphine. Following chronic morphine treatment, the maximum number of specific binding sites for 3H-dihydroalprenolol (3H-DHA) in parietal cortex and hippocampus showed a biphasic change, indicating an initial increase and decrease (relative to controls) in beta adrenoreceptors in these regions with time during withdrawal. No appreciable changes were observed in the dissociation constants for 3H-DHA binding. The changes in cortical beta adrenoreceptor density found in early (8 hr) and later phases (32 hr) of withdrawal were paralleled by a selective increase and decrease, respectively, in cortical neuron sensitivity to noradrenergic stimulation. These results suggest a possible linkage between changes in central adrenoreceptor function and the formation and/or expression of opiate dependence.
Collapse
|
141
|
Smith CB, Bennett-Kelly L, Woods JH. Comparison of "selective" opiate receptor antagonists on the isolated mouse vas deferens. Neuropeptides 1984; 5:161-4. [PMID: 6099488 DOI: 10.1016/0143-4179(84)90052-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The selectivity and relative potencies of opiate receptor antagonists were compared on the mouse vas deferens preparation. ICI-174864 was found to be a highly selective antagonist at delta opiate receptors equal in potency to naltrexone in blocking the actions of delta agonists. Although less potent than naltrexone, beta-funaltrexamine (beta-FNA) and Mr-1452, like naltrexone, were less selective in that they blocked the actions of mu, delta and kappa agonists. The relative potencies of beta-FNA and Mr-1452 in antagonizing the three types of agonists also were similar to naltrexone.
Collapse
|
142
|
Cameron OG, Smith CB, Hollingsworth PJ, Nesse RM, Curtis GC. Platelet alpha 2-adrenergic receptor binding and plasma catecholamines. Before and during imipramine treatment in patients with panic anxiety. ARCHIVES OF GENERAL PSYCHIATRY 1984; 41:1144-8. [PMID: 6095785 DOI: 10.1001/archpsyc.1984.01790230030004] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Specific binding of tritiated clonidine, an alpha 2-adrenergic receptor agonist, and tritiated yohimbine, an alpha 2-adrenergic receptor antagonist, to platelet membranes was measured in persons with panic attacks or major depression and in normal subjects. Plasma catecholamine levels were measured in patients with panic attacks and in normal subjects. The number of binding sites in patients with panic attacks, as measured with tritiated clonidine, was lower than in depressed persons and was the same as in normal subjects. The number in patients with panic attacks, as measured with tritiated yohimbine, was lower than in either depressives or normal subjects. Catecholamine levels were somewhat higher in patients with panic attacks than in normal subjects. Treatment with imipramine hydrochloride decreased the number of sites, as measured with either ligand, in both patient groups and increased catecholamine levels in patients with panic attacks.
Collapse
|
143
|
Weiss RJ, Dix BR, Kissner PZ, Smith CB. Altered platelet alpha 2 adrenoreceptors in orthostatic hypotension. Clin Cardiol 1984; 7:599-602. [PMID: 6094066 DOI: 10.1002/clc.4960071108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Alpha 2 adrenergic agonists have been used to raise blood pressure in patients with idiopathic orthostatic hypotension (IOH). In an attempt to define the mechanism of action of these agents, radioligand binding of [3H]clonidine, an alpha 2 agonist, and of [3H]yohimbine, an alpha 2 antagonist, to human platelet membranes from a patient with IOH was performed to determine the maximum number (Bmax) and dissociation constant (KD) for this receptor. There was a marked decrease in receptor number in this patient when compared to normal subjects. In normal volunteers the specific binding of [3H]clonidine yielded a mean Bmax of 33 +/- 2 fmol/mg protein and a KD of 5.5 +/- 0.6 nM, while for the patient the Bmax was 20 fmol/mg protein and the KD was 7.4 nM. For [3H]yohimbine binding in normals, the Bmax was 165 +/- 12 fmol/mg protein and the KD was 4.0 +/- 0.5 nM, whereas for the patient the Bmax was 65 fmol/mg protein and the KD was 12.0 nM. Alpha 2 adrenergic agonists such as clonidine decrease blood pressure by stimulating central presynaptic alpha 2 sites, and thus inhibiting sympathetic activity. There are also alpha 2 adrenergic receptor sites postsynaptically on vascular smooth muscle. The presence of this receptor postsynaptically in a patient with a reduction of the presynaptic inhibitory sites could account for clonidine's pressor activity in patients with IOH. Further study of both alpha 2-adrenergic receptors in patients with IOH may be important in developing an understanding of central and peripheral mechanisms in the control of blood pressure.
Collapse
|
144
|
Smith CB, Crane AM, Kadekaro M, Agranoff BW, Sokoloff L. Stimulation of protein synthesis and glucose utilization in the hypoglossal nucleus induced by axotomy. J Neurosci 1984; 4:2489-96. [PMID: 6491719 PMCID: PMC6564692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The metabolic responses of rat hypoglossal nuclei to unilateral section of the 12th cranial nerve have been studied. Changes in the rates of protein synthesis and glucose utilization in the regenerating nucleus were determined with two quantitative autoradiographic techniques, the L-[1-14C]leucine method and the [14C] deoxyglucose method, respectively. The results show that both of these processes increase in the nucleus ipsilateral to the sectioned nerve and are unaffected in the contralateral nucleus as compared with sham-operated animals. The time courses of these metabolic changes have been compared with that of the return of functional innervation of the tongue. An increase in glucose utilization is first detected 24 hr postaxotomy. It is maximal between 1 and 3 days postaxotomy and constitutes an 84% increase over the rate in the contralateral control nucleus. The increase in protein synthesis is of smaller magnitude than that of glucose utilization. It is maximal at 48 hr after axotomy and constitutes a 25% increase over the rate in the contralateral nucleus. The increases in both of these metabolic processes persist even after functional recovery of the tongue at 21 days postaxotomy. Protein synthesis and glucose utilization return to normal levels between 24 and 35 days postaxotomy. Although the time courses of the changes in protein synthesis and glucose utilization are similar, the magnitude of the increase in glucose utilization is too large to be accounted for by the energy requirements of the relatively small increase in protein synthesis and probably reflects other processes as well, including altered function of the soma-dendritic membrane of regenerating neurons.
Collapse
|
145
|
Hökfelt T, Smith CB, Norell G, Peters A, Crane A, Goldstein M, Brownstein M, Sokoloff L. Attempts to combine 2-deoxyglucose autoradiography and tyrosine hydroxylase immunohistochemistry. Neuroscience 1984; 13:495-512. [PMID: 6151149 DOI: 10.1016/0306-4522(84)90244-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The possibilities were analysed to combine the 2-deoxyglucose technique and indirect immunofluorescence histochemistry using tyrosine hydroxylase antiserum, with the aim to study functional activity in immunohistochemically characterized single neurons. Since the product measured with the 2-deoxyglucose method is water soluble and since immunohistochemistry requires that sections repeatedly run through aqueous media, the 2-deoxyglucose method was carried out before fixation and immunohistochemistry. The routine rapid thaw-mounting at + 60 degrees C of sections for 2-deoxyglucose autoradiography was found not to be compatible with immunohistochemistry. Instead a new mounting technique based on "gluing" the sections on to the object slide with a mixture of a standard mounting medium (Permount) and xylene was used to avoid diffusion at this stage. Two procedures were outlined, both starting with unfixed brains cut on a cryostat. In Method I autoradiographic sheet film was used. After autoradiographic exposure, the section was immersion-fixed in formalin, processed for immunohistochemistry, analysed and photographed in a fluorescence microscope and the results compared with the autoradiographic distribution patterns on the film. However, only the low resolution of the routine 2-deoxyglucose technique was obtained, which did not allow analysis of activity in single cells. In Method II, liquid emulsion applied by the loop technique was used. After exposure, autoradiographic developing and fixation, dehydration, mounting, analysis and photography of autoradiographs in the light microscope, the cover-slip was removed, the sections rehydrated and processed for indirect immunofluorescence histochemistry. With this procedure single autoradiographically labeled cells were observed, some of which contained tyrosine hydroxylase. Thus, with Method II it may in the future be possible to monitor functional activity in single immunohistochemically identified neuronal cell bodies. In order to obtain a useful and reliable method for this purpose, however, further extensive work with regard to, for example, quantification will be required.
Collapse
|
146
|
Cashman JS, Smith CB, Weidner M, Matsen JM. Evaluation of cost-effectiveness and rationale for use of a selective culture plate for isolation of Staphylococcus aureus from stool specimens. J Clin Microbiol 1984; 20:570-1. [PMID: 6436310 PMCID: PMC271372 DOI: 10.1128/jcm.20.3.570-571.1984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
An assessment was made of the necessity of performing routine screening for Staphylococcus aureus in stool specimens. A total of 527 stool specimens were evaluated. Because of the rare incidence of staphylococcal enterocolitis and the high ($2.50) screening cost, the results of this evaluation suggest that such a screening need not be performed routinely.
Collapse
|
147
|
Smith CB. Birth weights of fetuses exposed to diagnostic ultrasound. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 1984; 3:395-396. [PMID: 6384546 DOI: 10.7863/jum.1984.3.9.395] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The birth weights of newborns routinely subjected to diagnostic ultrasound antenatally are compared with the birth weights of infants delivered by the same physician over a similar span of time seven years earlier, when diagnostic ultrasound was not available. They are also compared with the birth weights of infants delivered by a physician in the same rural community who requested diagnostic ultrasound for less than 10 per cent of his pregnant patients. There is no apparent difference between the average weights of the infants subjected to diagnostic ultrasound and those who were not.
Collapse
|
148
|
Weiss RJ, Webb RC, Smith CB. Comparison of alpha 2 adrenoreceptors on arterial smooth muscle and brain homogenates from spontaneously hypertensive and Wistar-Kyoto normotensive rats. J Hypertens 1984; 2:249-55. [PMID: 6099386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Alpha 2 adrenoreceptors are located on vascular smooth muscle of the rat tail artery. In the present study this receptor was studied in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. Adrenergic agonists were used to produce isometric contractions of helically-cut tail artery strips from SHR and WKY. Clonidine and guanabenz, alpha 2 agonists, were more potent in the SHR than in the WKY (e.g. clonidine: EC50 SHR = 3.5 +/- 0.6 X 10(-8) M; EC50 WKY = 17.0 +/- 0.2 X 10(-8) M; P less than 0.0005). There was no difference in potency between the alpha 1 agonists, phenylephrine and methoxamine. Yohimbine, an alpha 2 antagonist, was more potent in inhibiting the clonidine-induced contraction in the SHR (pA2 = 7.66 versus 7.14). To determine the number of alpha 2 adrenoreceptors, the specific binding of 3H-clonidine to homogenates of tail artery and of five brain areas was also measured. The maximum number of high-affinity sites on the tail artery was threefold greater in SHR than in WKY (31 +/- 5 versus 11 +/- 3 fmol/mg protein, P less than 0.0005). No differences in the number or affinity of alpha 2 receptor sites was found in the hypothalamus, hippocampus, locus coeruleus or parietal cortex of the two strains of rat. There was a difference in the amygdala (SHR: 163 +/- 16 versus WKY: 108 +/- 14, P less than 0.05). The larger number of alpha 2 adrenoreceptors on the vascular smooth muscle in SHR may provide an explanation for the supersensitivity of SHR to adrenergic agonists.
Collapse
MESH Headings
- Animals
- Arteries/metabolism
- Arteries/physiology
- Brain/metabolism
- Clonidine/metabolism
- Clonidine/pharmacology
- Epinephrine/pharmacology
- Guanabenz/pharmacology
- In Vitro Techniques
- Male
- Membranes/metabolism
- Methoxamine
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Norepinephrine/pharmacology
- Phenylephrine/pharmacology
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Receptors, Adrenergic, alpha/drug effects
- Receptors, Adrenergic, alpha/metabolism
- Receptors, Adrenergic, alpha/physiology
- Yohimbine/pharmacology
Collapse
|
149
|
Rice HE, Smith CB, Silk KR, Rosen J. Platelet alpha 2-adrenergic receptors in schizophrenic patients before and after phenothiazine treatment. Psychiatry Res 1984; 12:69-77. [PMID: 6087398 DOI: 10.1016/0165-1781(84)90139-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The specific binding to isolated platelet membranes of 3H-clonidine, an alpha 2-adrenergic receptor partial agonist, and 3H-yohimbine, an alpha 2-adrenergic receptor antagonist, was measured in male, drug-free schizophrenic patients. The maximum number of binding sites (Bmax) for 3H-yohimbine was significantly lower in these patients than in normal subjects. Treatment with chlorpromazine (CPZ) for 2 weeks further decreased the Bmax for both ligands. Plasma catecholamine levels were determined before and after treatment. Before treatment, levels of dopamine and norepinephrine (NE) were within a normal range, while epinephrine (E) levels were significantly elevated. CPZ treatment significantly increased plasma NE levels, but decreased E levels to a normal range. These observations suggest that schizophrenia might be associated with abnormal noradrenergic function that is reflected by a decreased number of platelet alpha 2-adrenergic receptors.
Collapse
|
150
|
Smith CB. Physical principles of digital radiography. Radiography (Lond) 1984; 50:41-4. [PMID: 6709859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|